[The metabolism and biological activity of glucuronidation substrates in experimental diabetes mellitus]. / Metabolizm i biologicheskaia aktivnost' substratov gliukuronidirovaniia pri éksperimental'nom sakharnom diabete.

The study was undertaken to examine the impact of experimental diabetes mellitus on the biotransformation of some drugs, their toxicity and hypoglycemic action, as well as on the biotransformation of endogenous testosterone and the androgenic status. The accelerated metabolism of both exogenous and endogenous substrates which occurred in diabetes mellitus caused a decrease in their biological activity.

[Change in carbohydrate metabolism, secretion of insulin and glucagon in normoglycemic rats during administration of various doses of nicotinamide]. / Izmenenie uglevodnogo obmena, sekretsii insulina i gliukagona u normoglikemicheskikh krys pri vvedenii razlichnykh doz nikotinamide.

Development of hypoglycemia, a slight decrease in concentration of glucagon in blood as well as increase in activity of malate-and glucose-6-phosphate dehydrogenases in liver cytosol were detected in rats injected subcutaneously with nicotinamide at a dose of 31.25 mg/kg 6 hrs before decapitation. Increase of the single dose up to 125 mg/kg caused hypoglycemia, distinct increase in concentration of insulin and glucagon in blood plasma simultaneously with a pronounced inhibition of the enzymatic activity in liver tissue. Effect of nicotinamide on carbohydrate metabolism appears to have a dissimilar character depending on the drug dose: its small doses accelerated utilization and oxidation of glucose but did not affect the secretion of insulin and glucagon.

[Effect of nicotinamide on body glucose utilization in animals]. / Vliianie nikotinamida na utilizatsiiu gliukozy organizmom zhivotnykh.

A single administration of nicotinamide (62.5 mg/kg) was found to enhance the relative activity of exogenous insulin, to decrease glucose level in the peripheral blood, to increase the activity of malate dehydrogenase and glucose-6-phosphate dehydrogenase in the liver cytosol in intact mice and to increase the rate of exogenous glucose utilization in rabbits. The character of nicotinamide effect on carbohydrate metabolism in intact animals is suggested to be dose-dependent. When administered in low doses, the drug increases tissue sensitivity to endo- and exogenous insulin.

[Metabolic products of methandrostenolone in the body of white rats studied by high-performance liquid chromatography]. / Izuchenie produktov metabolizma metandrostenolona v organizme belykh krys metodom vysokoéffektivnoi zhidkostnoi khromatografii.

Metabolism of the anabolic steroidal hormone methandrostenolone in Wistar rats was studied by high performance liquid chromatography (HPLC) and redioisotope techniques. The conditions for isolation of methandrostenolone metabolites by HPLC were developed. Reduction of the double bonds was shown to be an early stage in methandrostenolone biotransformation. The main portion of the metabolites was excreted with urine as glucuronide conjugates. No sulfoesters were found.

[Dynamic distribution of methandrostenolone in the body of white rats]. / Dinamika raspredeleniia metandrostenolona v organizma belykh krys.

Dynamics of distribution of anabolic steroidal hormone methandrostenolone and routes of its elimination from the organism of Wistar rats were studied by using methods of radioisotopes and high-performance liquid chromatography. Methandrostenolone metabolites were shown to be excreted mainly in the urine. Methandrostenolone metabolism is a complicated process in the course of which redistribution of metabolites among various organs occurs. The anabolic effect of methandrostenolone is supposed to be due to the formation of its metabolites.

[Effect of insulin, adrenaline and cyclic adenosine monophosphate on the activity of transport adenosine triphosphatases and pyruvate dehydrogenase of the rat myocardium under normal conditions and in insular insufficiency]. / Vliianie insulina, adrenalina i tsiklicheskogo adenozinmonofosfata na aktivnost' transportnykh ATF-az i piruvat-degidrogenazy miokarda krys v norme i pri insuliarnoi nedostatochnosti.

Experiments with rats were set up to study the interaction of hormones with Na+, K+-ATP-ase and Ca2+-ATP-ase of the sarcoplasmatic reticulum fragments and with pyruvate-dehydrogenase of the myocardial mitochondria in healthy rats and the ones with alloxan diabetes. Insulin was found to activate, while epinephrine and c-AMP to inhibit Na+, K+-ATP-ase. The Ca2+-ATP-ase is activated with epinephrine and c-AMP. In alloxan diabetes Na+, K+-ATP-ase is inhibited and Ca2+-ATP-ase and pyruvate-dehydrogenase--activated.

[Influence of thyrocalcitonin on the adenosine triphosphatase activity and the electrolyte balance of the rat myocardium]. / Vliianie tirokal'tsitonina na adenozintrifosfataznuiu aktivnost' i élektrolitnyi balans miokarda krys

The effect of thyrocalcitonine on the calcium, sodium and potassium levels in the blood plasma of the rats' myocardium and also on the activity of Na+-, K+- and Ca2+- ATP-ase of the sarcoplasmatic cardiac reticulum fragments were studied in experiments with rats. Calcitonine was found to force down the level of calcium in the blood plasma and to raise the sodium content in the myocardium on rats. The drug lessened the activity of the myocardial Na+-, K+-ATP-ase.

[Stimulation by cyclic adenosine-3'5'-monophosphate by Na+, K+-activated ATPase from rabbit kidney]. / Stimuliatsiia (Na+ - K+)-aktiviruemoi ATF-azy pochek krolikov pod vliianiem tsiklicheskogo adenozin-3',5'-monofosfata

Cyclic 3',5-AMP in vitro increased the activity of Na+, K+-ATPase, isolated from cortex and medulla of rabbit kidney. Maximal stimulating effect was observed in kidney cortex at 10(-6) M concentration and in medulla at 10(-4) M concentration of 3',5'-AMP. Under these conditions the enzymatic activity was increased by 24.6 +/- 4.1% and 27.9 +/- 7.7%, respectively. These data suggest that Na+, K+-ATPase, activated by cyclic 3',5'-AMP, is directly involved in the mechanism of Na+ transport in cells of osmoregulating organs.

[Effect of catecholamines on the activity of rabbit kidney microsomal (na+--k+)-activated atpase]. / Vliianie katekholaminov na aktivnost' mikrosomal'noi (Na+--K+)-aktiviruemoi ATF-azy pochek krolikov

The significance of alpha- and beta-adrenoreceptors and the role of cyclic 3', 5' -AMP in the mechanism of the activation by catecholamines of the microsoma (Na+ - K+)-activated ATP-ase of the rabbits kidneys were investigated. Phentolamine did not obstruct the activating effect of epinephrine in the cortical and medullar layer. Inderal inhibited the reaction of the enzyme in response to epinephrine in the renal cortex and fully prevented any rise of the enzymatic activity in the medullar substances. Isopropylnorpinephrine and cyclic 3',5' -AMP stimulated the (Na+ - K+)-activated ATP-ase in the cortical and medullar layer. An inference is drawn to the effect that the activation of the enzyme occurring under the effect of catecholamines comes as a consequence of a beta-adrenoreceptors stimulation. It is suggested that the cyclic 3',5'-AMP may be directly involved in the mechanism accounting for stimulation by catecholamines of the activity displayed by the microsomal (Na+ - K+)-activated ATP-ase of the rabbits kidneys.