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S A Gavrilova

Publications and source records attributed to S A Gavrilova.

6 recordsLinked to original sources

[Secretory function of the endothelium as a factor of vascular tone regulation in the norm and in cardiovascular pathology].

Endothelin-1 and nitric oxide are the most potent factors of the endothelium-derived substances. The factors play opposite roles in regulation of cardiovascular system, and their interaction underlies the balance of vasoconstrictor and vasodilator influences on vascular tone under normal conditions. In our experiments, changes in endothelin-1 blood concentration were associated with affected production of endogenous nitric oxide. The altered interrelationships between the endothelium-derived vasoactive substances may precede pathological shifts in the cardiovascular system.

Animals↗

Chronic administration of interferon-a decreases blood pressure and heart rate in rats.

We studied the effects of interferon-alpha on rat cardiovascular system. Intravenous administration of intron-A in a dose of 100,000 IU/kg for 3 days led to a permanent and statistically significant decrease in blood pressure (on days 2 and 3) and reduction in heart rate. These effects were not associated with changes in baroreflex regulation of the cardiovascular system.

Animals↗

Active immunization against endothelin-1 is associated with a decrease in plasma endothelin-1 and changes in vascular reactivity.

Exogenous endothelin-1 (ET-1) or high concentrations of the peptide in pathological conditions have marked effects on vascular reactivity. In order to evaluate the role of endogenous ET-1 we investigated responsiveness of conduit (aorta) and of resistant-like (tail artery) vessels in ET-1-deficient rats. Elimination of circulating ET-1 was achieved by active immunization of Wistar rats with a peptide-haemocyanin conjugate (anti-ET-1 group), leading to a marked reduction in plasma level of the peptide in comparison with that of vehicle-treated animals (control group): 1.9 fmol/ml vs 4.9 fmol/ml, respectively. The immunization was associated with a slight elevation of mean arterial pressure, whereas heart rate remained unchanged. In the anti-ET-1 group rings of isolated aorta displayed reduced sensitivity to ET-1: EC50 = 6.57 nM vs 2.95 nM in the control group. Tail arteries of the ET-1-deficient rats showed diminished responses to ET-1, the maximal rise in perfusion pressure: +5.2 mmHg vs +13.6 mmHg in the control group. After immunization, rings of isolated aorta displayed no changes in endothelium-dependent relaxation to acetylcholine (Ach, EC50 = 0.20 microM vs 0.35 microM in the control group), whereas experiments on perfused tail artery showed a twofold reduction in Ach effects. Thus, depletion of circulating ET-1 induces slight changes in haemodynamics associated with altered vessel responsiveness to vasoactive substances.

Acetylcholine↗