Activation and Inhibition of Succinate-Dependent Ca²⁺ Transport in Liver Mitochondria during Adaptation

I. R. Saakyan^1*, S. G. Saakyan², and M. N. Kondrashova¹

¹Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino, Moscow Region, 142290 Russia; E-mail: saakyan@mail.ru

²Institute of Surgery, Armenian Ministry of Health, ul. Asratyana 10, Erevan, Armenia

^* To whom correspondence should be addressed.

Received December 22, 2000; Revision received March 20, 2001

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Succinate-dependent Ca²⁺ accumulation was investigated in rat liver mitochondria and in operation biopsies of patients under states either with prevalence of adrenergic influences (administration of activating doses of adrenaline, acute phase of immobilization stress, initial period after allogenic transplantation, and acute phase of myocardial infarction) or with prevalence of the reciprocal mediator acetylcholine (late period after transplantation, chronic ulcer disease of stomach and duodenum). Adrenaline prevalence leads to increase of succinate-dependent ATP synthesis and Ca²⁺ accumulation, which is due to known activation of succinate oxidation. However, together with activation, inhibition of these processes was revealed. The inhibition phase prevails under chronic pathology. Therefore, reciprocal regulation of succinate oxidation and succinate-dependent Ca²⁺ transport in mitochondria occurs in the body in the course of adaptation. The reciprocal regulation of mitochondrial processes is considered as a mechanism of reciprocal regulation of physiological functions.

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KEY WORDS: mitochondria, adrenaline, acetylcholine, stress, antigenic stress, Ca²⁺ transport, succinate oxidation, adaptation

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