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Biomedical subjects

A A Kromin

Publications and source records attributed to A A Kromin.

17 recordsLinked to original sources

[Functional organization of myogenic pacemaker of the stomach in conditions of hunger and satiation].

In chronic experiments, we have studied electrical activity of muscles of the gastro-esophageal sphincter, small curvature, corpus and antrum of the stomach in conditions of hunger, food intake behaviour and satiation of the rabbits. The aim of this study involved particularities of the electrical activity of myogenic pacemaker zone of the stomach. It has been shown that function of myogenic pacemaker of the rabbit stomach is performed by smooth muscles of the small curvature of the stomach. Pacemaker properties of muscles of the small curvature of the stomach are performed in conditions of food intake behaviour and satiation.

Action Potentials↗

[The mechanism of inhibition of small intestine contractions following irritation of rabbit's vagus nerve].

Explored was mechanism of inhibition of small intestine contractions due to weak irritation (0.5-2.5 V, 1-30 Hz, 0.3-1.0 ms) of the peripheral segment of rabbit's right vagus nerve. It was shown that the inhibitory effect can be blocked by benzohexamethonium, arphonade, atropine, rhausedyl, and a combination of propranolol and dehydroergotoxine. Inhibition is triggered by catecholamines released by sympathetic endings in consequence of activation of presynaptic M-cholinoreceptors on their surface. Presynaptic M-cholinoreceptors are activated by acetylcholine released by the endings of postganglionary parasympathetic nerve fibers.

Animals↗

[Electric activity of striated muscles of the cervical part of the rabbit esophagus under conditions of hunger, food intake and satiation].

The experiments of free-moving rabbits have shown that the muscles of the proximal zone in the esophageal cervical part functions as the superior esophageal sphincter. In hunger stage the motor unit activity of the sphincter has regular low-amplitude discharge with monomodal distribution of interspike intervals. The process of food satisfaction leads to the appearance of burst-like unit activity with bimodal distribution of interspike intervals. During the food intake reorganization of the motor unit activity of the esophageal cervical part is manifested in characteristic patterns of interspike interval distribution.

Animals↗

[Morphohistochemical and electrophysiological characteristics of the transverse striated muscles of the rabbit esophagus].

A specific histochemical profile of the muscular tunic of the stomach has been revealed; its myons demonstrate a high succinate dehydrogenase and myofibrillar ATPase activity. Electrical activity of the oesophageal musculature has common features with biopotentials of the skeletal muscles and the smooth musculature of the stomach. The similiarity with the skeletal muscle biopotentials is evident as a peculiar spike activity, especially at the time of feeding. In electrograms of the striated oesophageal muscles slow waves are seen; they change at deprivation and feeding. Therefore, it is possible to compare them with the smooth musculature capable to generate slow waves.

Acetylcholinesterase↗

[The integrating role of biological motivation in the realization of feeding and drinking behaviors].

In chronic experiments on rabbits with preliminary alimentary or water deprivation electrical and mechanic activity was studied of the chewer muscle proper and of the esophagus in the process of animals food or water taking. It has been established that in patterns of electrical and mechanic activity of the chewer muscle proper and esophagus specific differences of alimentary and drinking behaviour of animals are reflected. Dominating motivation of different biological properties determines the specific integration of motoneurones of chewing and swallowing centers and peripheral contraction elements of digestive tract in the functional systems of alimentary and drinking behaviour.

Action Potentials↗

[Electric and mechanical activities of the upper esophageal sphincter in rabbits].

Electrical and mechanical activities of the rabbit muscles in different zones of the esophageal cervical part were examined on free-moving rabbits with chronically implanted electrodes and force transducers under conditions of hunger and food intake. It is shown that the functional role of the circular muscles of the cranial end of the esophagus is determined by their participation in activity of the superior esophageal sphincter.

Action Potentials↗