AU666157B2 - Body tissue omega-3 fatty-acid-augmenting agent and nutrient composition containing the same - Google Patents

Description

b66615 7

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): SNOW BRAND MILK PRODUCTS CO., LTD.

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Invention Title: BODY TISSUE (0-3 FATTY-ACID-AUGMENTING AGENT AND NUTRIENT COMPOSITION CONTAINING THE SAME The following statement is a full description of this invention, including the best method of performing it known to me/us:

SPECIFICATION

TITLE OF THE INVENTION BODY TISSUE w-3 FATTY-ACID-AUGMENTING AGENT AND NUTRIENT COMPOSITION CONTAINING THE SAME BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an agent to augment w-3 fatty acids in body tissue, comprising a specific nucleotide admixture, and to a nutrient composition containing said agent. The agent or the composition can be used as a nutriment for a variety of patient conditions, an oral or enteral nutrient for pre-operative or post-operative patients, an infant formula, and the like.

S 2. Description of the Prior Art A nucleotide is the building block of the nucleic acids which constitute the body of a gene, and is an essen- S tial substance found universally in all organisms. That is, all organisms, including humans, synthesize nucleotides in eeeee an amount as required. However, very little is known about the nutritional significance of nucleotides, and research is still in the developmental stage.

Under these circumstances, what little research has been done concerning the physiological effect of nucleotides does provide us with the following information. For 2 example, it is previously known that nucleotides have bifidobacteria growth-promoting activity, and the intestinal bacterial flora predominating with bifidobacteria is established when nucleotides are fed to infants (Kozaburo Ito, Bulletin of the Kobe Medical College, 29, 1, 1968). Furthermore, it has been shown that nucleotides ingested orally are closely linked to the immune function. Namely, it is known that a lack of dietary nucleotides can suppress the cellular immune function in which T-cells are involved (Rudolph et. al., Adv. Exp. Med. Biol. 165, 175, 1984), generally resulting in an increase in the death rate of the experimental animals due to Staphylococcus aureus. Said report(Rudolph et. al.) further suggests that nucleotides S. ingested orally activate the natural killer cell function, and thereby for infants in particular, stimulate the maturation of their immune system.

In addition, it has been reported that an infant formula containing adenosine monophosphate, cytidine monophosphate, guanosine monophosphate, uridine monophosphate, and inosine monophosphate in a very specific 1:1:1:3:0.5 S molar ratio, namely, 1.32 mg, 1.12 mg, 1.49 mg, 3.42 mg, and 0.45 mg respectively per 100 g of powdered formula mix, stimulates the growth of Bifidobacterium bifidum Ti, a bacterium uniquely found in the intestines of breast-fed infants, and as a result, the fatty acid composition of blood serum of infants fed on this formula approximates that 3 of breast-fed infants (Japanese Patent Publication No.

35894/1991). However, the effectiveness of this formulation was studied for one very specific adn. ture ratio only, and the same effectiveness may not be assured if the ratio is changed. Furthermore, although a change was observed in blood serum fatty acid composition in infants fed on formula containing adenosine monophosphate, cytidine monophosphate, guanosine monophosphate, uridine monophosphate, and inosine monophosphate in a very specific ratio, the significance of this change, namely, any specific effects on the growth of the infant, was not discussed and remained unknown. In any case, in view of the fact that the difference in the nucleotide composition and content in human breast milk and aminal S' milk is one major nutritional difference between the two types of milk, then it is expected that nucleotide composition and content would have a major physiological impact.

However, aside from these reoorts on blood serum, there is virtually no information as to the effect of nucleotides on changing fatty acid composition in tissues and organs, such as brain, nor as to how nucleotides affect the functions of these tissues and organs.

As to fatty acid composition, it is known that polyunsaturated fatty acids such as arachidonic acid and S docosahexaenoic acid exist in large quantities in the brain and are closely linked to the function of the brain and the nervous system Svenner Holm, J. Lipid Resi, 9, 570, 4 1968). These polyunsaturated fatty acids are synthesized in the body from linoleic acid or alpha-linolenic acid as the starting material, but it is also said that natural synthesis of polyunsaturated fatty acids in humans, including infants, is insufficient and must be supplemented by oral ingestion. A means to increase these polyunsaturated fatty acids in the brain by the oral ingestion of these fatty acids and to improve learning ability was disclosed (Japanese Patent Laid-open No. 153629/1989). Attempts are being made to fortify polyunsaturated fatty acid content in infant formula by the use of fish oils such as sardine oil, but it is shown that these oils contain large quantities of eicosapentaenoic acid, which is hardly found in breast milk, and o might have deleterious effects on prostaglandin metabolism •coo ~and blood platelet aggregation (ESPGAN Committee on Nutrition Acta P ac diatr. scond; 80.887 1991).

Although trials on the oral ingestion of polyunsaturated fatty acids have thus been conducted, none of the results was satisfactory in terms of effectiveness in improving the functions of tissues and organs. Furthermore, e e there has been no research in which in stead of orally administrating polyunsaturated fatty acids, substances which stimulate the activity for synthesizing polyunsaturated fatty acids are alternatively administered. Moreover, with respect to fatty acid composition in body tissue, the mechanism for the synthesis and metabolism to form fatty acids in 5 tissues is different in two different way of administration; and there is virtually no information as to the alternative administration of the stimulative agent.

SUMMARY OF THE INVENTION In the course of intensive study on nucleotides in view of the above-mentioned technological environment, the inventors of the present invention found that certain nucleotide admixtures are closely linked to fat metabolism without the involvement of intestinal bacteria, thus affecting the fatty acid composition in body tissue in general, particularly in the brain, thereby the present invention being completed.

The objective of the present invention is to provide a nutrient composition containing nucleotides which change the fatty acid composition in body tissue, particularly in the brain, to increase the content of polyunsaturated fatty acids, in particular the c-3 fatty acids, thereby stimulating an improvement in the functions of the brain and nervous system, for example, learning ability.

This objective can be met by the following means.

Namely, the present invention is a body tissue fattyacid-augmenting agent, comprising an admixture which contains 15-85% by weight cytidine monophosphate and 15-85% by weight one or more other nucleotides selected from among uridine monophosphate, adenosine monophosphate, guanosine 6 monophosphate, and inosine monophosphate, or salts of said nucleotides in rate to the calculated weight of said nucleotides, as an effective component. Furthermore, the present invention is a nucleotide-fortified nutrient composition which is effective in augmenting w-3 fatty acids in body tissue, wherein said nucleotide admixture is added to a nutrient composition in an amount such that the final composition will contain at least 1.5 mg% by solid weight cytidine monophosphate and at least 1.5 mg% by solid weight one or more other nucleotides selected from among uridine monophosphate, adenosine monophosphate, guanosine monophosphate, and inosine monophosphate, or salts of said nucleotides in ratio to the calculated weight of said nucleotides.

S. The above-mentioned nucleotide-fortified nutrient Scomposition preferably contains 5-120 mg% by solid weight a nucleotide admixture comprising per the solid weight of the nutrient composition 1.5-55 mg% cytidine monophosphate, 0-20 mg% uridine monophosphate, 0-15 mg% adenosine monophosphate, 0-15 mg% guanosine monophosphate and 0-15 mg% inosine monophosphate, or salts of said nucleotides in ratio to the calculated weight of said nucleotides.

The present invention is based upon the discovery that the administration of a suitable concentration of S specific types of nucleotides, by a specific mechanism, affect the metabolism of fats, thereby changing the fatty acid composition in body tissue, particularly in the brain, 7 wherein polyunsaturated fatty acids, especially what are known as the w-3 fatty acids, are specifically augmented.

Intestinal bacteria are not involved in this activity, and in this sense, this effect is completely different from the effects found in conventional techniques. The fattyacid-augmenting agent and nutrient composition of the present invention can stimulate an improvement in the functions of the brain and nervous system, for example, increased learning ability and the like. To provide the nutrient composition, the w-3 fatty-acid-augmenting agent can be incorporated into a nrrt'et-+ composition such as infant formula and oral or enteral nutrients, which upon ingestion can, without any difficulty in administration, be efficacious for the development of an infant's brain, the recovery of the functions of a patient brain or nervous system and the like.

The body tissue w-3 fatty-acid-augmenting agent of the present invention increases the content of polyunsaturated fatty acids such as arachidonic acid and docosahexaenoic acid, particularly w-3 fatty acids, in the brain; S moreover, it can improve the functions of the brain and nervous system such as improved learning ability and the like.

DETAILED DESCRIPTION AND THE PREFERRED EMBODIMENTS The present invention will be explained in detail 8 below.

First, the body tissue fatty-acid-augmentation, which is the achievement of the present invention, will be explained.

Body tissue as referred to here in the present invention does not mean blood serum or the like. In the nucleotide-supplemented artificial milk according to Japanese Patent Publication No. 35894/1991 described above as a prior art, the nucleotides in said milk act upon intestinal bacterial flora to stimulate the growth of bifidobacteria, thereby causing a change in the fatty acid composition in the blood serum. In contrast, in the present invention, intestinal bacteria need not be involved, and the agent acts upon fat metabolism, thereby causing a change in the fatty acid composition not in blood serum but in body tissue, which is a major difference of the present invention from conventional ones.

That is, fatty acids in blood serum are different 0* from the fatty acids in body tissue. Fatty acids in body tissue accumulate through the metabolism of fats, requiring 000** a certain time period before any change becomes apparent.

The nucleotide admixture according to the present invention stimulates the synthesis of specific polyunsaturated fatty acids.

However, the activity of the body tissue w-3 fatty-acid-augmenting agent of the present invention does 9 not totally exclude any change in the fatty acid composition in blood serum; that is, the activity of said agent to change body tissue fatty acids causes a similar change in blood serum fatty acids. However, it should be noted that the converse that a given change in blood serum fatty acids is always accompanied by a similar change in body tissue fatty acids is not true.

Among body tissue, nucleotides have the most conspicuous effect on brain tissue. In experiments on rats (to be discussed in Examples thereinafter), a significant increase in polyunsaturated fatty acids, particularly the w-3 fatty acids, was found in the cerebral cortex. That is, although there was an increase in level of both arachidonic acid, an polyunsaturated acid, and docosahexaenoic acid, an polyunsaturated acid, the ratio of fatty acids to Aw-6 fatty acids content also increased, which signifies a preferential increase in the 3 fatty acids. The fatty acids, unlike the w-6 fatty acids, are closely linked to the synthesis of physiologically active substances such as prostaglandins. An increase in polyunsaturated fatty acid content accompanied by a selective increase in fatty see.

0* 06 acids are an effective means of improving the functions of the brain and the nervous system.

Polyunsaturated fatty acids include those which have two or more double bonds within the molecule, such as linoleic acid alpha-linolenic acid arachi- 10 donic acid eicosapentaenoic acid (20:5) and docosahexaenoic acid Linoleic acid and arachidonic acid are w,-6 fatty acids, while alpha-linolenic acid, eicosapentaenoic acid, and docosahexaenoic acid are w-3 fatty acids.

The w series of unsaturated fatty acids are defined by the position of the double bond closest to the methyl end of the molecule. The difference between and fatty acids is related to the ease of oxidation and other factors which account for the difference in physiological activity.

Upon administering the body tissue i-3 fatty-acid-augmenting agent of the present invention to rats, the polyunsaturated fatty acid content in the cerebral cortex increased from 16.1% in the control rats up to 21.2- 28.3% in the recipients, and the fatty acid ratio go** increased from 0.5 in th. control rats up to 1.0-1.1 in the recipients; that is, the agent stimulated the synthesis of fatty acids to a greater degree than the e- 6 fatty acids (to be discussed in the Examples thereinafter).

6 Consequently, this increased synthesis of w-3 fatty acids is to improve the functions of the brain and nervous system to improve learning ability, which is a remarkably effective finding.

°Subsequently, the nucleotides according to the present invention will be explained. This nucleotide admixture must at minimum contain cytidine monophosphate (CMP), plus one or more other nucleotides selected from among 11 uridine monophosphate (UMP), adenosine monophosphate (AMP), guanosine monophosphate (GMP), and inosine monophosphate

(IMP).

These nucleotides can be added in the free form, or alternatively can be added in a salt form such as a sodium salt or a potassium salt, wherein the same effectiveness can be obtained. However, if a salt of the nucleotides is used, the salt content must be considered, in which case, an amount equal to the nucleotide equivalent weight must be added. Hereinafter, the admixtures shall be explained to S include the nucleotide salt; that is, for example, cytidine monophosphate or salt thereof shall simply be referred to as

CMP.

There are no particular restrictions as to the molar ratio or the like by which CMP, UMP, AMP, GMP, and IMP are to be added, and can be specified over a comparatively wide range. However, CMP is a mandatory component, to which at least one other nucleotide must be added. Specifically, the nucleotide admixture comprises 15-85% by weight CMP, preferably 20-65% by weight, and 1E-85%, preferably 35-80% by weight one or more nucleotides selected from among AMP, GMP, IMP, and UMP.

The percentage content of UMP, AMP, GMP, or IMP is preferably be 0-60% by weight of UMP, 0-45% by weight of AMP, 0-45% by weight of GMP, and 0-45% by weight of IMP, but more preferably, the content is 6-60% by weight of UMP, 12 4.5-45% by weight of AMP, 1.5-45% by weight of GMP, and 1.5-30% by weight of IMP. However, as described above, the total content of these nucleotides in the admixture is between 15-85% by weight, preferably between 35-80% by weight. A nucleotide composition of this ratio will preferentially increase the w-3 fatty acids level in body tissue, making it feasible to improve learning ability.

Subsequently, the amount of the above-mentioned nucleotides required for efficacy will be explained. An admixture containing the preferred ratios of the individual nucleotides may not exhibit any effectiveness if the ingested amount is too small.

In experiments on the rat, it was essential to add to the feed, at minimum 1.5 mg% or more by solid weight CMP plus 1.5 mg% or more by solid weight one or more other S nucleotides selected from among UMP, AMP, GMP, and IMP in order for the admixture to be effective. That is, the content of CMP in particular was important to specifically increase the synthesis of w-3 fatty acids, and at least mg% (computed as solid weight) CMP in the feed was essential. More specifically, a feed containing a nucleotide admixture in 5-120 mg% by solid weight comprising mg% CMP, 0-20 mg% UMP, 0-15 mg% AMP, 0-15 mg% GMP, and 0-15 mg% IMP, is preferable to improve learning ability.

This nucleotide content is in excess of that in conventional nucleotide- supplemented artificial milk. For example, in 13 the above- mentioned Japanese Patent Publication No.

35894/1991, the CMP content is 1.12 mg% and the admixture ratio of each nucleotide is stringently limited. For a nucleotide admixture to impact upon the metabolism of fats, thereby improving the functions of the brain and nervous system, the nucleotide content must be greater than in the conventional preparation. However, in the prior art, since the above-mentioned finding was not conceived and the relationship between the nucleotides and the body tissue polyunsaturated fatty acid was not recognized, no trials were e conducted in adding nucleotides in excess of the essential amount; moreover, the improvement in the desired effectiveness could not be ascertained with nucleotide ratios based eoe e S" on the prior art, when large amounts were added and even if such amounts were added incidentally, the action and effec- *o S tiveness of the nucleotides as considered in the present invention did not enter at all into recognition.

The most preferable composition includes all of the above-mentioned nucleotides; particularly a nucleotide admixture containing 3.0-55 mg% CMP, 2.0-20 mg% UMP, 1.5-15 mg% AMP, 0.5-15 mg% GMP, and 0.5-10 mg% IMP, added to an amount between 7.5-115 mg% of the composition is the most preferable.

The above-mentioned results are rather surprising; however the interaction between CMP and the other four nucleotides and the mechanism by which these nucleotides 14 affect fatty acid synthesis remain unclear.

The addition of nucleotides in excess of the required amount dose not effect any greater improvement in functions, such as learning ability, of the brain and nervous system and large amounts of nucleotides transfer their unique flavor which affects the taste of the food product.

In particular, in administering large doses of nucleotides to rats by allowing them to ingest ad libitum, the adverse effect in taste, which prevents the ad libitum ingestion, has to be eliminated.

Feed is a nutrient composition, and for humans, eo nutrient compositions can be used as nutriment for a variety oo of patient conditions, oral or enteric nutrient for presurgical or postsurgical patients, infant formula and the like.

Desired nucleotide-fortified nutrient compositions can be S formulated by adding nucleotides in the amounts as described above to these compositions. By taking these compositions with each meal, a specific amount of nucleotides can be ~ingested. A nutrient composition as used herein includes those comprised of proteins, fats, carbohydrates, minerals, vitamins, and the like, and can be in the form of a powder, granules, solid, liquid, semi-liquid, emulsion, or the like.

The above-mentioned preferred admixture ratios of each nucleotide are computed for solid compositions. For liquid compositions, the quantities should be diluted to between 5- 50% of the amount for solid compositions. For 15 example, for a liquid composition in which the solid content is 13%, then 0.2-7.2 mg of CMP, 0-2.6 mg of UMP, 0-2.0 mg of AMP, 0-2.0 mg of GMP, and 0-2.0 mg of IMP per 100 ml are used. In particular, 0.4-7.2 mg of CMP, 0.2-2.0 mg of UMP, 0.2-2.0 mg of AMP, 0.06-2.0 mg of GMP, and 0.06-2.0 mg of IMP per 100 ml are preferably used.

Furthermore, the nucleotide admixture can be prepared into a form which is not used for a nutrient composition. For example, preparations containing the nucleotide admixture as an effective component can be formulated. That e is, excipients, emulsifiers, binders, flavoring components, coloring agents, and the like can be added as required to the nucleotide admixture, and the resultant preparation can be processed into capsules, tablets, granules, and the like.

These preparations enable the ingestion of nucleotides without the intake of food. Moreover, it is convenient that *9 e taste is virtually no longer a limiting condition. Furthermore, the concentration of each nucleotide can be freely adjusted, except that a minimum amount is required in order to improve the functions of the brain and nervous system.

With rats, desired results were obtained by feeding them 0.8-12 mg per 100 g of body weight per day. Ingestion of nucleotides in greater amounts did not produce better results. The above- mentioned amounts of nucleotides to be added are determined assuming that the nucleotides are regularly ingested with each meal. For infant formula being 16 used in place of breast milk, the ingestion of the proper amount is no problem, but in other cases, namely, if the nuc3eotides are to be ingested separately as a supplement to meals, the necessary amount to be ingested cannot be guaranteed. In this case, the nucleotide preparations, which can be easily taken at any time other than with meals, are highly effective. For humans, an ingestion of approximately 5-260 mg per 1 kg of body weight per day is preferred.

Further, an infant formula is a typical example of the nucleotide admixture to be used as a nutrient composition, which can stimulate the growth of the infant brain and S improve learning ability. However, in this case, the composition of the nucleotide admixture in the infant formula does not simulate breast milk (human milk). Breast milk, on average, contains 1.2 mg% CMP, 1.1 mg% UMP, 1.2 mg% AMP, 0.3 mg% GMP, and 0.3 mg% IMP, as per cent solids, which corre- S sponds in part to the nucleotide composition of the present invention, but differs overall, and the CMP content in *444 particular is lower.

.The body tissue w-3 fatty acid augmenting agent i and the nutrient composition, as described above, can be prepared by known methods. In doing so, appropriate consideration should be given to such facts that nucleotides can be hydrolized by phosphatases, phosphatases are unstable to heat, and nucleotides are comparatively stable to heat.

Since an improvement in the functions of the brain 17 and nervous system occur only after fats are metabolized and the fatty acids accumulate within the body, the consequence is observable normally 14-21 days after the administration of the nucleotide composition.

The effectiveness of the present invention will be understood from Examples which follow.

Example 1 A basic feed mix comprising 25.0% casein, soybean oil, 51.5% corn starch, 3.0% sucrose, 8.0% cellulose powder, 3.5% mixed minerals, and 1.0% mixed vitamins was prepared; to 100 g of this basic feed mix were added 26.0 mg of CMP, 2.8 mg of UMP, 4.8 mg of AMP, 3.2 mg of GMP and 3.2 S: mg IMP, and thus a feed for the experiment was prepared.

Rats (4-week old SD female rats) were fed ad libitum on this feed over a period of 28 days, and then the composition of the fatty acids of a phospholipid fraction of the cerebral

C

cortex was analyzed. Results were compared with those of a control group to which a feed without nucleotides were fed, and are shown in Table 1. On average, the rats ingested a total of 4.8 mg of nucleotides per 100 g of body weight per day, according to the calculation.

18 Table 1 Fatty Acid Composition of Rat Cerebral Cortex r r r Fatty Acid Nucleotide-fed Group Control Group (No Nucleotide) C 16:0 13.8(4.3) 35.0(6.6) C 18:0 25.0(4.6) 20.1(5.3) C 18:1 13.0(2.5) 16.2(2.6) C 18:2 0.5(0.08) 0.6(0.12) C 20:2 0.1(0.01) 0.2(0.01) C 20:3 w-6 0.4(0.07) 0.2(0.07) C 20:4 (a-6 8.5(0.83) 5.8(0.91) C 22:4 w-6 2.6(0.51) 1.2(0.93) C 22:5 a-3 0.1(0.02) 0.1(0.02) C 22:6 (r-3 12.2(2.1) 5.52(1.8) Saturated Fatty Acids 39.3(7.0) 56.4(8.9) Unsaturated Fatty Acids 44.4(2.5) 36.6(4.7) Saturated/Unsaturated 0.9(0.12) 1.6(0.37) w-6 12.1(1.0) 7.9(0.8) 12.3(1.6) 5.6(1.4) w-3/ -6 1.0(0.09) 0.5(0.12) or more C atoms 2.3(2.9) 16.1(1.8) Average Value[%] (Standard Deviation) From the resulLs it was confirmed that, with respect to the phospholipid fatty acid composition in the 0 *Sr 0 0 19 cerebral cortex of rats fed on the nucleotide-fortified feed, the concentration of polyunsaturated acids such as arachidonic acid and docosahexaenoic acid increased and that the fatty acid ratio increased. The results also confirmed that the ratio of saturated fatty acids to unsaturated fatty acids was smaller in rats fed on the nucleotide-fortified feed than in rats fed on the feed without nucleotides. Furthermore, another group of rats (5 rats per test group) similarly fed ad libitum on the test feed of the same composition as described above, were studied to deter- S mine their learning ability by a water maze method. For this test, a rat was set free at a point in the maze and the time it took for the rat to find and swim to the finishing Spoint was measured, and the number of trials it took for the rat to memorize the path was counted. This maze test was performed in accordance with the method of Yonekubo (Shoku no Kagagu, 161, 47, 1991). The swim tests were conducted 8 times per day for 4 days. Rats fed on the nucleotidefortified feed memorized the route by the 3rd trial on day 2, with the average time to complete the maze being 13 seconds and no increase in time was observed thereafter; in contrast, rats fed on the feed without nucleotide did not memorize the path until the 4th trial on day 3 and no increase in time was observed thereafter. This difference can be attributed to the ingestion of the nucleotides, which increased the polyunsaturated fatty acid content in the 20 brain, further affecting the learning ability of the rats.

Example 2 A nucleotide admixture comprising 50.8 mg of CMP, 15.4 mg of UMP, 11.6 mg of AMP, 11.6 mg of GMP and 11.6 mg of IMP was added to the same basic feed as used in Example 1, and an experiment was carried out in the same manner as in Example 1. The rats ingested a total of 12 mg of nucleotides per 100 g of body weight per day. The fatty acid composition in the cerebral cortices of the rats is shown in Table 2.

t.o. Table 2 Fatty Acid Composition of Rat Cerebral Cortex SFatty Acid Nucleotide-fed Group C 16:0 13.1(2.6) i C 18:0 26.2(4.2) 0 C 18:1 -9 12.5(2.4) C 18:2 w)-6 0.5(0.09) C 20:2 w-6 0.1(0.01) SC 20:3 w-6 0.4(0.08) C 20:4 wI-6 9.0(0.8) C 22:4 w-6 2.7(0.6) C 22:5 0.1(0.02) C 22:6 13.6(1.7) Saturated Fatty Acids 38.8(6.0) Unsaturated Fatty Acids 46.2(3.2) 21 Saturated/Unsaturated 0.8(0.08) 12.8(2.0) w-3 13.7(1.9) i -6 1.1(0,10) or more C atoms 28.3(3.0) Average Value[%] (Standard Deviation) The results indicate that in comparison with the control group of Example 1 which were fed on the feed without nucleotides, the nucleotide admixture of this Example *6 6 6 acted to increase the polyunsaturated fatty acid content, 6 and to increase the fatty acid ratio. Furthermore, it is confirmed by the water maze test that these test rats learned the route by the 2nd trial of day 4.

Subsequently, a feed was prepared in which the S• concentration of each nucleotide was twice as much as the 6* above example and used and the experiment was carried out in the same manner as above, from which results virtually the same as found in the example above were obtained in the analysis of fatty acid composition and in the water maze test. However, in this case, a sensory evaluation test showed that the taste of the nucleotides adversely affected the flavor of the feed, and the rats ingested a total of 18 mg of nucleotides per 100 g of body weight per day, or less than twice the amount of the previous example.

Example 3 22 A nucleotide admixture comprising 3.0 mg of CMP, 2.3 mg of UMP, 1.5 mg of AMP, 0.7 mg of GMP, and 0.7 mg of IMP was added to the same basic feed as used in Example 1, and an experiment was carried out in the same manner as in Example 1. The rats ingested a total of 1.0 mg of nucleotides per 100 g of body weight per day. The fatty acid composition in the cerebral cortices of the rats is shown in Table 3.

Table 3 *4 Fatty Acid Composition of Rat Cerebral Cortex Fatty Acid Nucleotide-fed Group C 16:0 15.2(2.0) SC 18:0 23.8(2.3) C 18:1 c)-9 13.7(2.1) C 18:2 0.5(0.05) C 20:2 0.1(0.01) C 20:3 0.3(0.03) C 20:4 8.0(0.77) C 22:4 0-6 2.3(0.20) C 22:5 e-3 0.1(0.02) C 22:6 (j-3 11.2(1.2) Saturated Fatty Acids 42.0(4.3) Unsaturated Fatty Acids 42.2(3.3) Saturated/Unsaturated 1.0(0.12) w-6 10.7(1.1) 23 11.3(0.8) -6 1.1(0.09) or more C atoms 24.8(2.1) Average Value[%] (Standard Deviation) The results showed that in comparison with the control group of Example 1 which were fed on the feed without nucleotides, the nucleotide admixture of this example acted to increase the polyunsaturated fatty acid content, and to increase the fatty acid ratio. Furthermore, it was confirmed by the water maze test that these test rats 6 learned the route by the 4th trial of day 2.

Example 4 A nucleotide admixture comprising 1.5 mg of CMP, mg of UMP, 1.5 mg of AMP, 1.5 mg of GMP, and 1.5 mq of IMP was added to the same basic feed as used in Example 1, and an experiment was carried out in the same manner as in Example 1. The rats ingested a total of 0.9 mg of nucleotides per 100 g of body weight per day. The fatty acid composition of the cerebral cortices of the rats is shown in Table 4.

Table 4 Fatty Acid Composition of Rat Cerebral Cortex Fatty Acid Nucleotide-fed Group C 16:0 24.6(5.4) 24 S...i Sn.

4

S

0 C 18:0 21.9(3.5) C 18:1 w-9 15.0(2.1) C 18:2 a,-6 0.5(0.06) C 20:2 w-6 0.2(0.01) C 20:3 0.3(0.04) C 20:4 u-6 7.4(0.44) C 22:4 w-6 2.2(0.17) C 22:5 0.1(0.01) C 22:6 w-3 10.2(1.0) Saturated Fatty Acids 46.4(4.0) Unsaturated Fatty Acids 45.8(4.2) Saturated/Unsaturated 1.0(0.10) w-6 10.6(1.2) w-3 10.3(1.3) w-3/1 -6 1.0(0.11) or more C atoms 22.2(2.5) Average Value[%] (Standard Deviation) The results indicate that in comparison with the control group of Example 1 which were fed on the feed without nucleotides, the nucleotide admixture of this example acted to increase the polyunsaturated fatty acid content, and to increase the fatty acid ratio. Furthermore, it was confirmed by the water maze test that these test rats learned the route by the 5th trial of day 2.

Example *4 *i

S

*a S 5 25 A nucleotide admixture comprising 3.0 mg of CMP, 0.0 mg of UMP, 0.0 mg of AMP, 2,Q.Qmg of GMP, and 1.9 mg of IMP was added to the same basic feed as used in Example 1, and an experiment was carried out in the same manner as in Example 1. The rats ingested a total of 0.8 mg of nucleotides per 100 g of body weight per day. The fatty acid composition in the cerebral cortices of the rats is shown in Table Table *4 Fatty Acid Composition of Rat Cerebral Cortex Fatty Acid Nucleotide-fed Group C 16:0 25.9(3.0) SC 18:0 21.6(2.4) C 18:1 15.7(1.6) C 18:2 w-6 0.6(0.06) S C 20:2 w-6 0.2(0.01) C 20:3 w-6 0.3(0.05) C 20:4 w-6 7.0(0.41) SC 22:4 t-6 1.9(0.11) C 22:5 w-3 0.1(0.01) C 22:6 w-3 9.8(0.63) Saturated Fatty Acids 48.8(2.8) Unsaturated Fatty Acids 42.5(3.2) Saturated/Unsaturated 1.0(0.16) w-6 9.9(0.75) 26 0-3 9.9(1.00) -6 1.0(0.13) or more C atoms 21.2(1.9) Average Value[%] (Standard Deviation) The results indicate that in comparison with the control group of Example 1 which were fed on the feed without nucleotides, the nucleotide admixture of this example acted to increase the polyunsaturated fatty acid content, and to increase the fatty acid ratio. Furthermore, it was confirmed by the water maze test that these test rats s* learned the route by the 8th trial of day 2.

6*.

Example 6 6 *6 A nucleotide admixture comprising 4.0 mg of CMP, 0.9 mg of UMP, 2.0 mg of AMP, 0.0 mg of GMP, and 0.0 mg IMP was added to the same basic feed as used in Example 1, and an experiment was carried out in the same manner as in Example 1. The rats ingested a total of 0.8 mg of nucleoa tides per 100 g of body weight per day. The fatty acid composition in the cerebral cortices of the rats is shown in Table 6.

6e Table 6 Fatty Acid Composition of Rat Cerebral Cortex Fatty Acid Nucleotide-fed Group C 16:0 26.0(6.7) 27 9 .99.

0 *0*9 *0 *r S *5S9 C 18:0 21.7(2.7) C 18:1 w-9 15.5(2.8) C 18:2 a,-6 0.5(0.07) C 20:2 w-6 0.2(0.01) C 20:3 w-6 0.3(0.04) C 20:4 7.1(0.86) C 22:4 c,-6 2.0(0.38) C 22:5 0-3 0.1(0.01) C 22:6 w-3 10.0(0.9) Saturated Fatty Acids 48.1(9.0) Unsaturated Fatty Acids 42.8(3.3) Saturated/Unsaturated 1.1(0.30) 10.0(1.2) 10.1(1.2) 1.0(0.10) or more C atoms 22.5(4.5) Average Value[%] (Standard Deviation) The results indicate that in comparison with the control group of Example 1 which were fed on the feed without nucleotides, the nucleotide admixture of this Example acted to increase the polyunsaturated fatty acid content, and to increase the fatty acid ratio. Furthermore, it was confirmed by the water maze test that these test rats learned the route by the 7th trial of day 2.

Comparative Example 1 28 A nucleotide admixture comprising 1.1 mg of CMP, 3.4 mg of UMP, 1.7 mg of AMP, 1.5 mg of GMP, and 0.45 mg of IMP was added to the same basic feed as used in Example 1, and an experiment was carried out in the same manner as in Example 1. The rats ingested a total of 1.0 mg of nucleotides per 100 g of body weight per day. The fatty acid composition in the cerebral cortices of the rats is shown in Table 7.

Table 7 S Fatty Acid Composition of Rat Cerebral Cortex Fatty Acid Nucleotide-fed Group C 16:0 27.0(3.6) C 18:0 22.6(2.5) C 18:1 w-9 15.2(2.5) C 18:2 0.5(0.05) C 20:2 w-6 0.2(0.01) C 20:3 w-6 0.3(0.04) C 20:4 8.7(0.62) C 22:4 wj-6 2.5(0.22) C 22:5 w-3 0.1(0.02) C 22:6 m-3 6.6(0.51) Saturated Fatty Acids 48.5(4.7) Unsaturated Fatty Acids 41.7(3.6) Saturated/Unsaturated 1.2(0.23) 12.2(1.2) 29 w-3 6.7(0.71) t-3/w-6 0.55(0.09) or more C atoms 20.1(2.0) Average Value[%] (Standard Deviation) The results indicate that in comparison with the control group of Example 1 which were fed no nucleotides, the nucleotide admixture of this Example acted to increase the polyunsaturated fatty acid content, but the cu-3/,-6 fatty acid ratio was virtually the same with that of the k* control group. Furthermore, it was confirmed by the water maze test that the test rats learned the route by the 3rd trial of day 3. Thus, also with respect to learning ability, there was no noticeable difference between the rats of the control group and the those of this Comparative Example.

This can be attributed to the fact that although the total ingested amount of nucleotides was virtually the same as in Experiments according to the present invention, the amount of ingested CMP was smaller.

Claims (2)

1. A method of improving learning ability, comprising orally administering to an infant in need an effective amount of an infant formula containing 3.0-55 mg% of cytidine monophosphate, 2-20 mg% of uridine monophosphate, 1.5-15 mg% of adenosine monophosphate, mg% of guanosine monophosphate, 1.5-15 mg% inosine monophosphate or an amount of salt thereof equivalent to the amount of nucleotide monophosphate, wherein 15-85% by weight of the total amount of nucleotide monophosphates is cytidine monophosphate or an equivalent amount of said salt of cytidine monophosphate, such that 0.8-12 mg of total nucleotide monophosphates are administered per 100 g of body weight per day. 15

2. The method of Claim 1, wherein said cytidine monophosphate is present in an amount not less than the 0 amount of the other nucleotide monophosphates. 0 eee *o ao *go staff/unitalkeep/32003.93_SW 11.5 ABSTRACT OF DISCLOSURE A body tissue c)-3-group fatty acid augmenting agent in which an effective component is a nucleotide admixture comprising 15-85% by weight cytidine monophosphate and by weight one or more other nucleotides selected from among uridine monophosphate, adenosine monophosphate, guano- sine monophosphate, and inosine monophosphate or salts of said nucleotides in ratio of the calculated weight of said nucleotides, or a nucleotide-fortified nutrient composition in which said nucleotide admixture is added to a nutrient S composition in an amount such that the final composition contains 1.5 mg% or more by solid weight cytidine monophos- 0* phate and 1.5 mg% or more by solid weight one or more other S nucleotides selected from among uridine monophosphate, adenosine monophosphate, guanosine monophosphate, and ino- o S 0 sine monophosphate, or salts of said nucleotides in ratio of the calculated weight of said nucleotides. This nucleotide 00006: admixture or nucleotide- fortified nutrient composition makes it possible to augment c-3-group fatty acids such as docosahexaenoic acid in the cerebral cortex and to stimulate the development of the functions of the brain and nervous function, for example, the learning ability.