ABSTRACT
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.
Subject(s)
Adenosine Triphosphate/biosynthesis , Calcium/metabolism , Epinephrine/metabolism , Mitochondria, Liver/metabolism , Stress, Physiological/metabolism , Succinic Acid/metabolism , Acute Disease , Adaptation, Physiological , Adenosine Triphosphate/agonists , Animals , Calcium/agonists , Duodenal Ulcer/metabolism , Epinephrine/pharmacology , Humans , Male , Mitochondria, Liver/drug effects , Myocardial Infarction/metabolism , Rats , Rats, Wistar , Succinic Acid/agonists , Transplantation, Homologous/physiologyABSTRACT
A protocol is developed for preparation of concentrated rat liver homogenate preserving assemblies of mitochondria in isotonic KCl under 0 and 15 degrees C. Assemblies preserve ability for self-organization during storage in homogenate. All key energy functions of mitochondria can be investigated in such a homogenate. Oxidative phosphorylation and membrane potential are stable for 5-7 h and can be still observed on the next day. Substrate-level phosphorylation is better pronounced for mitochondria in KCl than in sucrose medium while Ca2+ capacity is greater and lipid peroxidation is much lower. Sucrose addition impairs these functions. The rate of phosphorylating respiration is lower in large assemblies and higher in small. Transition from large to small assemblies corresponds to the transition from quiescent state of animal to adrenaline induced active state. The proposed method is particularly convenient for clinical investigations with small bioptates.
