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Biomedical subjects

D P Bilibin

Publications and source records attributed to D P Bilibin.

At least 19 recordsLinked to original sources
PubMed2005

Uncoupling of afferent and myoelectric reactions in portions of gastroduodenal complex in acute damage period.

In two series of experiments on cats, afferent reactions of organs of the gastroduodenal complex (gastric corpus, pylorus, and duodenal bulb) were studied and myoelectric activity of these portions of the gastroduodenal complex was examined. In each series, only one portion of the gastroduodenal complex was stimulated with electrical pulses. It was found that processes underlying changes in functional heterogeneity and enhancement or moderation of their interrelations in the acute damage period can affect the development of early regional adaptation.

Acute Disease↗
PubMed2003

Role of stomach regions and duodenum in the formation of electrical activity of gastroduodenal complex.

Functional activity of components of the gastroduodenal complex (gastric cardia, gastric corpus, pylorus, and duodenal bulb) was studied in 4 series of acute experiments. One of these regions was subjected to electrical stimulation in each series. Our results suggest that the cardia possesses rhythm-forming properties, the corpus plays a system-organizing role, the pylorus plays a trigger role, and the duodenal bulb produce synchronizing effects.

Animals↗
PubMed2002

Role of serotoninergic structures in coordination of electric activity in the gastroduodenal complex.

Myoelectric activity in various portions of the stomach and duodenum in normal and after vagotomy and intravenous injection of serotonin adipinate was studied in acute experiments on cats. Vagotomy disturbed coordination of myoelectric activity in the stomach and duodenum. Intravenous injection of serotonin adipinate restored coordination and increased myoelectric activity in the stomach, particularly, in the pylorus. Under these conditions the pacemaker of myoelectric activity in the gastric corpus and autonomic regulation of the duodenum were preserved. Intravenous injection of serotonin adipinate most significantly changed myoelectric activity in the pylorus. Myoelectric activity in the cardia increased after vagotomy against the background of serotonin adipinate. Our findings suggest that serotoninergic structures maintain functional heterogeneity of digestive organs and coordinate their interrelationships.

Adipates↗
PubMed2002

Osteovisceral afferent interrelations.

The effects of stimulation of intraosseus receptors on visceral afferent reactions were studied in experiments on anesthetized cats. Stimulation of intraosseus receptors decreased the thresholds of evoked potentials recorded in the cerebral cortex in response to stimulation of the heart, stomach, and duodenum. It was concluded that stimulation of intraosseus receptors during osteopathy (e. g. increased intraosseus pressure) increases sensitivity of visceral sensory systems and can provoke the development of pain syndromes. It is important that visceral pain in such cases should be considered as a symptom of organ pathology, but not as a manifestation of vertebrovisceral syndrome.

Afferent Pathways↗
PubMed1992

[Role of the vagus nerve in mechanisms of the modulation of afferent duodenal effects].

The electrostimulation of vagal nerves, the effect of naloxone and atropine on duodenal afferentation by registering evoked potential (EP) at cortex on direct electrostimulation of duodenum have been studied in acute experiments on cats. It has been established that the stimulation of afferent portion of vagal nerves causes the effect of deprivation of EP, whereas the stimulation with certain intensity of efferent portion of vagal nerves intensifies the duodenal afferentation. The effect of afferentation easeness (relief) has been blocked by the application of naloxone 10-20 microgram on duodenal bulbus, but not on it's i. v. injection and without effect on local application of atropine. It is concluded that the role of vagal nerves on the modulation of duodenal nociception is due to the activation of opiate terminals of the efferent vagal nerve portions.

Animals↗
PubMed1991

[Hypothalamo-bulbar regulation of afferent reactions of intact and altered heart].

Afferent reactions of the heart were studied by registration of evoked potentials (EP) in acute experiments on cats. It was established that the hypothalamo-bulbar structures take part in regulation of heart afferentation through depressive effects descending along the system of the vagus nerves. In this case increase of the activity of the posterior hypothalamus in the period of acute myocardial ischemia due to activation of neurons of the motor nucleus of the vagus nerves leads to depression of excitation processes on the neurons of the intracardiac nervous system, while the zones of the anterior hypothalamus exert a relieving effect on heart afferentation.

Afferent Pathways↗
PubMed1990

[Characteristics of cortical representation of the components of the gastroduodenal complex and role of the vagus nerve in the regulation of visceral afferentation].

Evoked potentials were registered at the cortex of both hemispheres of the brain during electrical stimulation of the body of the stomach, pylorus and duodenum pre and post bilateral vagotomy. It has been demonstrated that duodenum is represented at the cortex more widely in comparison with other parts of the gastroduodenal complex. Bilateral vagotomy increases amplitude of the evoked potentials, more substantially at the right hemisphere, that may be connected with enhancement of excitability of the irritating structure by exclusion of the efferent influence of vagal nerves, which take part in the regulation of visceral afferentation at the level of end organ nervous system.

Afferent Pathways↗
PubMed1988

[Participation of the opioid-ergic system in the regulation of afferent reactions of the damaged myocardium].

It has been established that in lesion of the myocardium accumulation of huge amount of algesic compounds may cause limitation of the level of cardiac afferentation. Use of naloxone, buterfanol tartrate and D-ala-2-lei-enkephalin prevent the development of the reaction. The possibility of participation of the endogenic cardiac opioids in anti-nociceptive reactions of heart during its lesion is considered.

Animals↗
PubMed1987

[Characteristics of cardiac regulation in ischemic damage to the ventricular myocardium].

The evoked potentials produced by the irritation of the heart sinus node zone in the brain cortex and bradycardia have been registered in 5 to 40-min ischemia of the left and right ventricular myocardium during the electrical stimulation of the vagus. Restricted cardiac afferentation and the heart escape from vagus influences have been revealed at the early stages of ischemia.

Afferent Pathways↗
PubMed1987

[Mechanisms of cutaneous-cardial interconnections].

Using the method of double stimuli, some features of inhibitory influences of conditioning stimulation of cutaneous zones on the afferent transmission from the heart were studied in the experiments on cats. It has been shown that when the interval between testing and conditioning stimuli is from 50 to 150 ms, the cutaneous stimulations effectively block the appearance of evoked potentials in the rostral parts of the cerebral cortex, which were induced by the electrical stimulation of the sinoatrial nodal zone. Bilateral vagotomy completely eliminated this reaction. Stimulation of the peripheral part of the cut vagus also effectively blocked the transmission of the afferent impulses from the heart. It was concluded that inhibitory cutaneo-cardiac effects are determined by the mechanisms of presynaptic inhibition, which develop at the level of intracardiac nervous system.

Animals↗
PubMed1987

[Afferentation of the heart in pathological states of the myocardium].

The state of afferent connections between sinoatrial node zone (SNZ) in the normal and affected myocardium (reversible ischemia, necrosis) and rostral parts of the brain cortex (RPC) was studied with the help of evoked potentials in acute experiments on cats. Interruption of afferent connections (SNZ-RPC) during reversible ischemia and experimental myocardial necrosis of the right ventricle was revealed. Ultramicroscopic data of SNZ studies as well as electrophysiologic changes registered in RCP during irritation of the peripheral part of the right vagus nerve and local application of GABA on SNZ suggest possible interruption of cardiac afferentation at the level of SNZ due to the mechanism of presynaptic inhibition.

Afferent Pathways↗
PubMed1986

[Effect of alcohol on conduction of afferent impulsation from the area of the sinus node of the heart to structures of the central nervous system].

Acute experiments in cats, using the induced potentials technique, showed intraperitoneal 30% alcohol administration (1.5-2 ml per 1 kg body weight) as well as direct application of 2 or 3 ml of similarly concentrated alcohol solution to the sinus node area (SNA) to block afferent impulse conduction from the SNA to central nervous structures, such as cerebral cortex, reticular formation of the midbrain, peri-aqueduct gray matter. The fact that the induced potentials generated within the cerebral cortex and subcortical structures in response to SNA stimulation showed a pattern of change that was similar to the one associated with alcohol administered intraperitoneally or applied directly to SNA has suggested that alcohol may block the cardiac afferent flow directly at the level of SNA structures.

Animals↗
PubMed1985

[Cortical representation of the heart sinus node zone].

Evoked potentials (EP) arising in response to electrical stimulation of the heart sinus node zone (SNZ) were registered in the cortex of the large hemispheres (LHS) of cats. EP with the shortest latent period (LP) of 18-19 months were recorded both in the left and right hemispheres in the area of a cross-shaped cleft (associative field PCA, partially the I motorsensor zone and the I sensorimotor zone). Besides, EP with a more durable LP (20-21 months) were registered in the 2nd sensorimotor zone. EP remained unchanged after bilateral vagotomy and disappeared after spinal cord cutting at C-2 level. The presence of the functional centre regulating cardiac activity in the branch sections of LHS is suggested.

Animals↗