[Effect of acetylcholine of substrate oxidation in heart mitochondria]. / Deistvie atsetilkholina na okislenie substratov v mitokhondriiakh serdtsa.

Acetylcholine has been studied for its effect on respiration and oxidative phosphorylation in mitochondria from the heart of a rat and guinea pig. Acetylcholine in doses of 25, 50 and 100 mg per 100 g of the body weight 5, 15 and 30 min after intraperitoneal injection intensifies the rate of phosphorylative respiration at ketoglutarate oxidation and moderately lowers it at succinate oxidation. Malonate increases the activating influence of acetylcholine on oxidation of alpha-ketoglutarate in the heart mitochondria and aminooxyacetate decreases it. Phosphorylative respiration with oxidation of pyruvate and isocitrate is not changed essentially under the action of acetylcholine. Introduction of acetylcholine stimulated most strongly the aminooxyacetate-sensitive portion of respiration, a mixture of aminotransferases in the activation of alpha-ketoglutarate oxidation under effect of acetylcholine. The stimulating action of acetylcholine on alpha-ketoglutarate oxidation is mediated by M- and H-cholinoreceptors, since it is abolished by their blockers: atropine and benzohexonium. Stimulation of alpha-ketoglutarate oxidation by acetylcholine is mostly expressed under introduction of beta-adrenoblocker obsidan which provides prevalence of the parasympathetic nervous system. This stimulation is more intensive in the guinea pig as a more cholinergic animal in comparison with a rat.

[Acetylcholine activation of alpha-ketoglutarate oxidation in liver mitochondria]. / Aktivatsiia atsetilkholinom okisleniia alpha-ketoglutarata v mitokhondriiakh pecheni.

Activation of alpha-ketoglutarate oxidation in the rat liver mitochondria takes place 15 and 30 min after intraperitoneal injection of acetyl choline. This mediator in doses of 25, 50 and 100 micrograms per 100 g of body weight causes a pronounced stimulation of phosphorylation respiration rate and calcium capacity of mitochondria with alpha-ketoglutarate oxidation. Acetyl choline is found to have a moderate inhibitory action on oxidation of lower (physiological) concentrations of succinate. Its stimulating action on alpha-ketoglutarate oxidation is associated with activation of M-cholinoreceptors; atropine, a choline-blocker, removes completely this effect. It is supposed that alpha-ketoglutarate and succinate are included into the composition of two reciprocal hormonal-substrate nucleotide systems.

[High adrenaline sensitivity of the mitochondrial processes in the mucosa of the small intestine in rats]. / Vysokaia chuvstvitel'nost' k adrenalinu mitokhondrial'nykh protsessov v slizistoi obolochki tonkoi kishki krysy.

Higher adrenalin sensitivity of mitochondrial processes in the small intestinal mucosa compared to that in liver mitochondria, was revealed under specially devised conditions of work with isolated mitochondria retaining their natural properties. Fifteen minutes after intraperitoneal injection of adrenalin into rats in a dose of 5 micrograms/100 bw an increase in Ca2+ capacity was seen only in intestinal mucosa mitochondria. The adrenalin-induced activation of oxidative phosphorylation was more remarkable in intestinal than in liver mitochondria at the initial stages of adrenalin action. The effect of adrenalin was completely reversed by the beta-blocker propranolol only in liver mitochondria. After 3 hours the adrenalin-induced activation of phosphorylation in the mitochondria ceases, whereas in the small intestinal mucosa it still persists.

[Isolation and features of the functioning of mitochondria of the small intestine mucosa in the rat]. / Vydelenie i osobennosti funktsionirovaniia mitokhondrii slizistoi obolochki tonkogo kishechnika krysy.

A modification is suggested for the method of intact mitochondria isolation from rat thin intestine mucosa. Mitochondria are obtained which can in vitro transport Ca2+ simultaneously with phosphorylation of the added ADP. Kinetic advantages of succinate in providing oxidative phosphorylation as compared with NAD-dependent substrates are much more pronounced in mitochondria of the thin intestine mucosa than in other tissues, and Ca2+ transport occurred only under succinate oxidation. As compared with liver mitochondria these mitochondria are shown to be more sensitive to adrenaline and calcium action.

[Effect of adrenaline on calcium transport and oxidative phosphorylation in mitochondria]. / Vliianie adrenalina na transport kal'tsiia i okislitel'noe fosforilirovanie v mitokhondriiakh.

Intraperitoneal adrenaline injection induces in 15 and 30 min an increase in the phosphorylation rate, calcium capacity and Ca2+ retention time in the rat liver mitochondria. A rise of the phosphorylation rate is inhibited by inderal, a beta-adreno-blocker. Energy metabolism grows considerably with succinate exchange intensification.

[Effect of acetylcholine on incorporation of 14C-precursors into uridylic and cytidylic nucleotides of the RNA of digestive glands]. / Vkliuchenie 14C-predshestvennikov v uridilovye i tsitidilovye nukleotidy RNK pishchevaritel'nykh zhelez pod vliianiem atsetilkholina.

The incorporation rate of [2-14C]orotic acid and [2-14C]uridine into the cytidylic RNA nucleotides is significantly lower than into the uridylic ones. In the liver it was twice as low as in the stomach mucosa or in pancreas of albino rats. The administration of acetylcholine in combination with proserine has no influence on the RNA content and its nucleotide composition in the tissues. The administered drugs however caused changes in the relation of the incorporation rates of both labels into uridylic and cytidylic RNA nucleotides, which evidences for the uridylic nucleotide synthesis. In the liver such changes are not detected, but utilization of the labeled uridine is shown to be more intensive for the cytidylic RNA nucleotides synthesis.