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V A Lebedeva

Publications and source records attributed to V A Lebedeva.

11 recordsLinked to original sources
PubMed1982

[Tissue chemoreceptors].

Intraarterial administration of acids or perfusion with solutions inducing acidosis in the small intestine tissue, increase the afferent impulsation in the splanchnic nerves as well as the arterial pressure in anesthetized cats. Threshold concentrations of lactic and carbonic acids don't exceed, at that, their normal contents in the blood and tissues. Similar data were obtained in perfusion of the small intestine with blood of a donor animal whose acid--alkaline balance (AAB) was altered. The tissue receptors were found to be more sensitive to the metabolic rather than respiratory acidosis, due to different alteration of of the intratissue pH. Sensitivity of the skeletal muscles' chemoreceptors proved somewhat lower as compared with the small intestine receptors. Nevertheless, the threshold shifts of the AAB parameters in the m. gastrocnemius perfusion developed within the normal range. The changes of minute volume of ventilation revealed the possibility of tissue receptors participation in the reflex control of respiration as well. The data on adequate sensitivity of the tissue receptors to terminal products of aerobic and anaerobic metabolism: carbonic and lactic acids, once more corroborate V. N. Tchernigosky's ideas of the tissue chemoreceptors as a special class of receptor structures providing the c.n.s. with necessary information on intensity of the tissue metabolism.

Acid-Base Imbalance↗
PubMed1976

[Responses of small intestine tissue chemoreceptors to change in the pCO2, pH and (HCO3-) in perfusion solutions].

Perfusion of the small intestine of anesthetized cats with a solution having excessive CO2 and H+ concentration (pCO2 60 mm Hg; pH; 7.2; [HCO3-] 25 MM) produced a threshold reflex increase in the blood pressure. The subsequent increase of pCO2 to 380 mm Hg and decrease of pH to 6.4 evoked a gradual raise of the blood pressure (8.0+/-0.6 mm Hg) followed by the sharp increase of pressor reflexes amplitude within the range of pH 6.4--6.1. Tissue receptors were found to be essentially sensitive to solutions imitating metabolic acidosis (decrease of [HCO3-] within the physiological range of pH changes (pH 7.1--6.8). Solutions with pH 6.4--6.1 imitating respiratory acidosis (increase of pCO2) were more effective than those imitating metabolic acidosis. The possible role of interstitial pH changes in responses of the tissue chemoreceptors to CO2, is discussed.

Animals↗
PubMed1975

[Changes in blood pressure and impulse activity in intestinal nerves during exposure of small intestine interoreceptors to lactic acid].

I. a. administration of threshold concentration (0.2 ml 7.8 mM) of lactic acid into the small intestine was found to increase afferent and efferent impulsation in the intestinal nerves as well as the systemic arterial blood pressure in anesthetized cats. Increase in the lactic acid concentration up to 250 mM/l resulted in two-phasic augmentation of the nerve responses and of the pressor reflexes. In the range from 7.8 to 62.5 mM/l of lactic acid concentration the absolute magnitude of pressor reflexes was 2.3 +/- 0.6--4.2 +/- 0.5 mm Hg. Further increase in the lactic acid concentration (up to 250 mM/l) produced on augmentation in the reflexes magnitude up to 18 +/- 2.8 mm Hg. A possible functional role of afferent impulses generated by the tissue receptors following an increase in metabolites concentration in the organs, is discussed.

Animals↗