JPH0411525B2 - - Google Patents

Description

Claim 1 An animal in need of treatment for reducing the heme metabolic rate is treated with tin-protoporphyrin or chromium-protoporphyrin in an amount effective to reduce the heme metabolic rate and suppress the bilirubin concentration in the blood. A method for reducing the metabolic rate of heme in a non-human animal, the method comprising administering. 2. The method according to claim 1, wherein tin-protoporphyrin is administered. 3. The method according to claim 1, wherein chromium-protoporphyrin is administered. 4 Approximately 0.05 to 1 μmol of tin per 1 kg of animal weight
2. The method of claim 1, wherein protoporphyrin or chromium-protoporphyrin is administered. 5. An amount of tin effective to reduce the rate of bilirubin accumulation in neonatal non-human animals immediately after birth.
2. The method of claim 1, comprising administering protoporphyrin or chromium-protoporphyrin. 6. The method according to claim 5, wherein tin-protoporphyrin is administered. 7. The method according to claim 5, wherein chromium-protoporphyrin is administered. 8. The method according to claim 5, wherein 10 to 25 μmol of tin-protoporphyrin or chromium-protoporphyrin is administered per kg of body weight of the animal. 9. A drug for reducing the metabolic rate of heme, containing an amount of tin-protoporphyrin or chromium-protoporphyrin effective to decrease the metabolic rate of heme and suppress the bilirubin concentration in the blood, and a pharmaceutically acceptable carrier. Composition. 10. The composition according to claim 9, which contains tin-protoporphyrin. 11. The composition according to claim 9, which contains chromium-protoporphyrin. 12. The composition according to any one of claims 9 to 11, wherein the carrier is a buffered physiological aqueous solution. 13. The composition according to claim 12, wherein the buffered physiological aqueous solution has a pH of 7 to 8. 14 Buffered physiological aqueous solution 100-2500μ per liter
14. A composition according to claim 12 or 13, containing moles of tin-protoporphyrin or chromium-protoporphyrin. 15 0.1 to 1 milliliter of buffered physiological aqueous solution
Claim 1 containing 2.5 μmol of tin-protoporphyrin or chromium-protoporphyrin
Composition according to item 2. 16. The composition according to claim 12, wherein the buffered physiological aqueous solution is a buffered physiological saline. 17. The composition according to claim 12, wherein the buffered physiological aqueous solution is a buffered physiological glucose aqueous solution. 18. A composition according to any one of claims 9 to 17 in dosage unit form. 19 Freeze-dried powder claims 9-
19. The composition according to any one of Item 18. 20. The composition of claim 9, containing an amount of tin-protoporphyrin or chromium-protoporphyrin effective to reduce the rate of bilirubin accumulation immediately after birth in a newborn mammal. 21 Claim 20 in which the newborn mammal is a human
Compositions as described in Section. 22. The composition according to claim 21, which is prepared in a dose of 0.1 to 2.5 μmol per kg of human body weight. 23 Claim 2 in which the newborn mammal is an animal
Composition according to item 0. 24. The composition according to claim 23, prepared at a dosage of 10 to 25 μmol per kg of animal body weight. 25. The composition of claim 9, containing an amount of tin-protoporphyrin or chromium-protoporphyrin effective to reduce the increase in bilirubin concentration in an adult mammal. 26. The composition according to claim 25, wherein the mammal is a human. 27. The composition according to claim 26, which is prepared in a dose of 0.05 to 1 μmol per kg of adult body weight. 28. The composition according to claim 25, wherein the mammal is an animal. BACKGROUND OF THE INVENTION The present invention relates to methods and compositions useful for reducing the metabolic rate of Heme in mammals.
More specifically, the present invention provides methods for reducing the rate at which heme is metabolized in the living mammalian body.
Concerning the use of metal protoporphyrins. Iron protoporphyrin, which is called heme. More precisely, ferroprotoporphyrin is a specific porphyrin isomer in mammalian blood. Heme is an essential component in the respiratory system and energy transfer reactions that occur within the mammalian body. Heme is synthesized and degraded by known metabolic routes via known enzymatic reactions. In the normal decomposition process, heme first undergoes a ring-opening reaction to become biliveridin and then to bilirubin. Bilirubin is toxic, or this toxicity is usually not manifested. The reason is that biliverdin immediately binds to albumin and is sent to the liver. In the liver, the protein is liberated and bilirubin reacts with uridine diphosphoglucyuronide to form the corresponding diglyquyuronide. Digluquiuronide is dissolved and excreted. Many homologs synthesized from iron protoporphyrin are known. They are commercially available;
Alternatively, it can be easily synthesized by known methods. Examples include platinum, zinc, nickel, cobalt, copper, silver, manganese, chromium, and tin protoporphyrins. For convenience, these compounds are generally referred to as metal-
It is written as protoporphyrin. Individually, chromium-
Protoporphyrin, tin-Protoporphyrin indicates a compound of chromium and tin. One of the more difficult aspects of bilirubin toxicity is that
Referred to as "neonatal jaundice," it is caused by undesirably high levels of bilirubin in the blood of newborn mammals. During the period immediately after birth, heme concentrations in mammals are high. It also has high heme oxygenase activity. This enzyme is essential for the metabolism of heme to bilirubin. A combination of factors results in extensive heme metabolism and elevated bilirubin concentrations in the newborn's body fluids. Since bilirubin is yellow, newborns appear yellow and can be called "neonatal jaundice." Free bilirubin is fat-soluble and easily crosses the blood-brain barrier, causing widespread and serious brain damage. One manifestation of bilirubin toxicity is kernicterus or bilirubin brain disease. External symptoms include coma, stiffness and tension, high-pitched crying,
Fever, convulsions, and death may occur. or,
Survivors are often left with cerebral palsy, choreoacetoid symptoms, deafness, intellectual retardation, and other psychiatric disorders in their newborn and early childhood years. The main treatments for severe bilirubinism are phototherapy and blood exchange. In the former procedure, the patient received 420
-470nm, which increases the oxidation of bilirubin and
It also results in a change to a currently unknown substance. Although this procedure is widely used, especially in the United States, unanswered questions about its safety and effectiveness remain and it is not satisfactory. A more surgical blood exchange procedure is employed for all neonates when the unconjugated bilirubin content is 20 mg/dl. For premature newborns, the concentration needs to be as low as 9 mg/dl for blood exchange, and generally speaking, the concentration should not exceed 2.0 mg/dl in order to not pose a risk to the newborn. This is the limit. However, it is desirable to keep the level of this highly toxic chemical below 2 mg/dl as much as possible. When bilirubin appears in high concentrations in the blood of adult humans and other mammals, sickle cell anemia,
Acquired liver disease is often present along with Mediterranean anemia and other congenital anemias. In such individuals, bilirubin concentrations are unlikely to reach concentrations as high as in newborns. However, toxic concentrations have been reached and should be controlled. From the above, it would be desirable to have a method or substance available that suppresses the metabolism of heme and reduces the rate at which it is degraded and the rate at which it accumulates in the blood. be. DISCLOSURE OF THE INVENTION The rate of heme metabolism in mammals can be improved by administering an effective amount of a synthetic metal protoporphyrin.
It was found that it can be reduced. Presently preferred are tin-protoporphyrin and chromium-protoporphyrin. Both of these compounds can be easily synthesized and used in a purer framework at a reasonable cost. They are water soluble and can be formulated with a variety of pharmaceutically acceptable carriers. Tin compounds appear to be more active. To determine the effect of tin-protoporphyrin on controlling the rate of heme metabolism, newborn rats were injected subcutaneously with a 0.1 ml solution of tin-protoporphyrin at 12, 24, 48, and 72 hours after birth. To make the parenteral injection, the material was dissolved in a small volume of 0.2N caustic soda, brought to pH=7.4 with 1N hydrochloric acid, and then adjusted to 0.9% sodium chloride. The composition prepared and used in this way had an injection volume of 0.1 ml.
It contained about 100 μmol/Kg body weight of tin-protoporphyrin. Control newborn rats were injected with the same volume of saline at each time point. Newborn rats are grouped (6-30 rats per group)
The animals were dissected at predetermined time intervals. Heme oxygenase activity and bilirubin concentration were analyzed in treated and control animals. Since heme oxygenase is essential for heme catabolism, an increase in heme oxygenase activity means an increase in the rate of heme catabolism. Heme oxygenase was described by Maines and Kappas in J. Biol. Chem., 253, 2321-2326 (1978).
Analyzed as described. Total bilirubin in serum was evaluated by the method of Roth, Clin Chem. Acta. 17, 487-492 (1967). In a six-week experiment, as for the controls,
The level of heme oxygenase in the neonatal liver increases rapidly, reaching 4 levels above that found in the adult liver.
It reaches double levels and then gradually declines, returning to normal adult levels between days 21 and 42.
In neonates treated with tin-protoporphyrin, administration of the active drug completely suppressed the normal and significant increase in heme oxygenase activity in the liver after birth. In these neonates, heme oxygenase activity immediately (day 1) falls to levels less than half that of controls, remains significantly lower than control levels for about 3 weeks, and finally reaches normal levels by about day 42. control levels were reached. Administration of tin-protoporphyrin rapidly and clearly reduces serum bilirubin levels in treated animals. This low level of bilirubin concentration persisted until about day 4, and then remained at nearly the same level as controls for the remainder of the 42-day study period. In a similar study, neonatal rats were given 2 chromium-protoporphyrin per kilogram after birth.
and 10 micromolar subcutaneous treatment. Heme oxygenase activity and bilirubin concentration were analyzed in various organs. Results were compared to each of the controls that received subcutaneous 0.1 ml saline treatment. Table 1 shows the results of heme oxygenase activity in the liver, kidneys, and paralysis in terms of heme oxygenase activity in nanomoles per milligram of granule protein per hour. As can be seen from Table 1, the efficacy of administering chromium-protoporphyrin is to rapidly reduce heme oxygenase. Similar results are found in the second
In the table, concentrations were observed for serum bilirubin, expressed in milligrams per deciliter.

【table】

Table: A study was conducted in adult rats treated with strontium-protoporphyrin to determine the effects on heme oxygenase activity and bilirubin production. Three rats, each weighing approximately 230 g, were injected subcutaneously with 50 μmol/Kg of tin-protoporphyrin in physiological saline at pH 8. Three control animals were given the same treatment with physiological saline. Rats were sacrificed 16 hours after treatment. Granular protein (Microsomal Protein) was evaluated for each liver and three kidneys combined,
Heme oxygenase activity was measured by Mearns and Katsupers method. This method measures heme oxygenase activity by quantifying the amount of bilirubin produced. The results are shown in Table 3.
The concentration unit for bilirubin is 1 nanomole of bilirubin produced per milligram of protein per hour.

[Table] From the above, it is easy to see that tin-protoporphyrin is highly effective in reducing bilirubin production and heme oxygenase activity in adult mammals. With regard to newborn mammals, the therapeutic composition of the invention may be administered immediately after birth to
It is administered at a dose of 25 μmol, and in humans at a dose of 0.1 to 2.5 μmol per kg of body weight. Although any conventional parenteral route may be employed, intramuscular and intravenous injections are preferred. Usually, one injection is sufficient to maintain the bilirubin concentration at the desired low level until the newborn reaches an age when heme metabolism equilibrates. However, it is preferred to monitor serum bilirubin concentrations and utilize efficacy enhancers as necessary. Your doctor or veterinarian will select the appropriate dosage. Dosages generally fall within the ranges listed above, but may be varied to treat particular conditions. In adults suffering from sickle cell anemia or other conditions in which bilirubin levels increase, the dosage unit is usually smaller, since in all but the most acute conditions bilirubin levels are lower than in newborns. This is because it is not very high. The standard dose for adults is usually about 0.05 to 1 μmol per kg of body weight. To enable the availability of suitable dosage units, the compositions of the invention are usually formulated in large quantities at a concentration of 100 to 2500 μmol per buffered physiological aqueous solution with a pH of 7 to 8.
Subdivide into dosage units containing approximately 0.1-2.5 μmol/ml of solution. Typical pharmaceutical carriers have a pH of about 7-8, usually
7.4 buffered saline or glucose solution. Alternatively, the therapeutic composition can be provided in lyophilized powder form and reconstituted with water to the clinical dosage. For example, a selected metal protoporphyrin can be made into a physiological solution by placing it in 0.1 molar phosphate or other pharmaceutically acceptable buffer containing sufficient saline or other solutes, and then lyophilized into a powder. can do. Add distilled water or salt solution to the powder to make solution 1.
The solution contains 0.1 to 2.5 μmol/ml of metal protoporphyrin per milliliter.