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Biomedical subjects

L V Filippova

Publications and source records attributed to L V Filippova.

At least 19 recordsLinked to original sources
PubMed1999

Changes in afferent impulse activity of small intestine mesenteric nerves in response to antigen challenge.

Sprague-Dawley rats (weight 130-150 g) were sensitized by an intraperitoneal injection of 1 mg chicken egg albumin with 0.25 ml Freund's adjuvant to stimulate immunoglobulin E antibody production. Leukocyte migration inhibitory factor was used as an indicator of animal sensitization. In acute electrophysiological experiments on sensitized animals, an intra-arterial or intraluminal chicken egg albumin (100 microg) challenge evoked a 10% enhancement of the activity of mesenteric nerves of the small intestine, regardless of the injection site chosen. Afferent nerve activity in control animals was not changed during the chicken egg albumin challenge. Morphometry at the light microscope level showed activation of mast cell degranulation after the antigen challenge to presensitized rats. Intraluminal injections of a stimulator of mast cell degranulation, compound 48/80 (20-30 mg), were found to increase afferent discharges in intact rats. An antagonist of H1 histamine receptors, clemastine, reduced the effect of compound 48/80. The results obtained provide direct evidence for the stimulation of sensory nerve endings by mast cell mediators released during mast cell degranulation.

Afferent Pathways↗
PubMed1998

[Cost benefit of detection and treatment patients with tuberculosis in Ivanovo region, Russian Federation].

To execute the tuberculosis control programme in the Ivanovo Region, the authors calculated the cost of detection of a tuberculosis case at patients' referrals to a therapeutical-and-prophylactic institution for medical aid and during prophylactic X-ray fluographic examinations and the cost of tuberculosis cure while treating the patient at a hospital in the intensive treatment phase (2-3 months) and in the outpatient setting or at a day hospital by the intermittent method in the continued treatment phase. The costs calculated were compared with those obtained by early approaches. The cost of detection of a tuberculosis case was 1580.8 for referrals in 1996 and 4000 for X-ray fluographic prophylactic examinations. The costs of hospital tuberculosis cure (85% cure rates) only in the intensive treatment phase (for 2-3 months) and outpatient intermittent treatment (for 2-4 months) with and without meals were 2415.34 and 2142.17 respectively. If the efficiency is equal, the introduction of new approaches to organizing the detection and treatment tuberculosis cases may save 3877.7 for each cured tuberculosis case and 2419.2 for each patient detected.

Ambulatory Care↗
PubMed1996

Mast cell mediators excite the afferents of cat small intestine.

The influence of intra-arterial injections of 5-hydroxytryptamine, histamine and prostaglandin E2 on afferent impulse activity of mesenteric nerves of small intestine was studied. In anaesthetized cats 5-hydroxytryptamine (10(-5)-10(-4) M) and histamine (10(-5)-10(-3) M) were shown to increase the impulse activity in a dose-dependent manner. Metergolin, 5-hydroxytryptamine antagonist, suppressed the effect of 5-hydroxytryptamine. Clemastine and cimetidine, antagonists of H1 and H2 histamine receptors respectively, distinctly diminished excitatory histamine effects. Prostaglandin E2 (10-30 micrograms/kg) enhanced the afferent impulse activity. The results suggest that afferents of the small intestine may be involved in reception of inflammatory and immune responses.

Animals↗
PubMed1996

[The effect of the mast-cell mediators histamine and prostaglandins on the afferent nerve fibers of the small intestine in the cat].

Histamine was shown to increase afferent impulse activity of the small intestine's mesenteric nerves in a dose-dependent manner, the effect being reduced by antagonists of the H1 and H2 histamine receptors. PG E2 and PC D2 also enhanced the afferent impulse activity. Interaction of antigens with the intestinal mast cells seems to participate in immune response.

Afferent Pathways↗
PubMed1992

[The localization of neurons in the nodose ganglion of the cat that innervate the rostral portion of the duodenum].

The method of axonal transport of horseradish peroxidase was used for studying the sites of localization and morphological features of sensory neurons of the vagus nerve in the left and right ganglion nodosum innervating the rostral part of the duodenum. Animals under nembutal narcosis were given 90-100 mcl of 33% solution of horseradish peroxidase ("Olaine", Riga RZ 2.7) injected into a limited area (1 x 1 sm) of the muscular layer of the duodenum. Horseradish peroxidase labelled neurons were found bilaterally in the both ganglia. The number of neurons in the left ganglion was 91 +/- 23, in the right one--115 +/- 24. The sensory cells are mainly of the ellipsoid form and of different sizes. Areas of sections of the neurons vary from 100 to 1300 mkm2, most on them having the area from 300 to 700 mkm2. The distribution of neurons according to the sizes of their areas have no substantial differences in the left and right ganglia. It was found that 65% of neurons in the right ganglion and 67% in the left one are localized in its caudal half.

Animals↗
PubMed1992

[Extra-organ sources of parasympathetic innervation of small intestine in the region of ligament of Treitz].

Localization sites of neurons in the dorsal motor nucleus of cat vagus innervating the duodenal-jejunal region and upper part of the jejunum were investigated using the technique of the retrograde axonal transport of horseradish peroxidase. Most part of the neurons was located within the ventrolateral area of the nucleus from +1.0 to +2.7 mm (according to obex). Morphological features of the ganglion nodosum neurons which organize afferent innervation of the intestine were analyzed. It has been shown that the maximal amount of such neurons is concentrated in the medium and caudal parts of the ganglion.

Afferent Pathways↗
PubMed1991

[The localization of neurons innervating the upper portion of the duodenum in the dorsal motor nucleus of the vagus nerve].

In anesthetized cats, using method of the retrograde transport of the horseradish peroxidase and electrophysiological techniques, the dorsal motor nucleus neurons innervating upper portion of the duodenum were found. Maximal number of such neurons were found within 1.0 to 2.5 mm rostral to the obex. The effects of the neurons stimulation on the electrical activity of the duodenum smooth muscles were studied. Possible role of the dorsal motor nucleus neurons in realisation of gastro-duodenum motor reflexes is discussed.

Action Potentials↗
PubMed1985

[Changes in pulmonary ventilation after shafts in acid-base equilibrium in the skeletal muscles of the cat].

In anesthetized cats, perfusion of the m. gastrocnemius with solutions simulating metabolic acidosis produces a reflex enhancement of breathing proportional to the acidosis degree. Perfusion with solutions having pH 7.0, 6.8 and 6.3 induced 4.6 +/- 1.0, 6.3 +/- 0.5 and 10.3 +/- 1.2% increases of the minute volume of ventilation, resp. These increases were mainly due to increases of the tidal volume rather than of respiratory rate. An increase of the mean blood pressure also occurred whereas heart rate did not change significantly. Hindlimb perfusion experiments revealed that reflex changes of the blood pressure and breathing depended on the muscle mass perfused. Possible participation of the muscle receptors sensitive to changes of metabolism in exercise hyperpnea, is discussed.

Acidosis↗
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↗
PubMed1981

[Possible role of muscle receptors in regulating arterial pressure during shifts in acid-base balance in muscles].

It has been shown on anesthetized cats that perfusion of the gastrocnemius muscle with a solution simulating metabolic acidosis (pH 7.1, [HCO3-]-12.7 mM, PCO2- 38 mmHg) produces a threshold reflex increase in the arterial blood pressure. The relationship between the magnitude of the pressor reflexes and the decreased bicarbonate concentration and pH is depicted by a curve that consists of two areas: an initial progressive rise of the blood pressure is replaced after pH 6.6 by a more abrupt increase in the intensity of the pressor reflexes. The results indicate that the muscle receptors may take part in arterial blood pressure regulation during acid-base changes in the skeletal muscle.

Acidosis↗
PubMed1978

[Analysis of the mechanism of action of carbonic acid on tissue chemoreceptors].

Perfusion of the small intestine of anesthetized cats with a solution imitating metabolic acidosis (pH = 7.3; [HCO-3] = =20.2 mM; PCO2 = 38 mm Hg) produced a threshold reflex increase in the blood pressure. The subsequent decrease of [HCO-3] to 3.2 mM and pH to 6.5 evoked a gradual raise of the blood pressure followed by a sharp increase of pressor reflexes amplitude within the range of pH 6.5--6.3. Solutions imitating metabolic acidosis (pH = 7.1; [HCO-3] = 12.7 mM) were found to increase the concentration of H+ ions in the outflow perfusate and blood pressure to larger extent than solutions imitating respiratory acidosis (pH = 7.1; PCO2 = 75 mm Hg). If the solution pH was held constantly at 7.4 by simultaneous decreasing PCO2 and [HCO-3] by a factor of two, a reflex increase in the blood pressure and decrease of perfusate pH had no effect either on blood pressure or perfusate pH. The data obtained suggest that one of the primary determinants of different responses of the tissue chemoreceptors to CO2 is the interstitial pH.

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↗