[Changes in autoregulation of coronary blood flow in rats with various sensitivity to stress].
The purpose of work: study of a role of endothelial nitric oxide in development of stress-induced changes in autoregulation of coronary blood flow in rats with various types of behaviour. The experiments were performed on isolated hearts of female-rats, in the "open field" test, depending on the type of impelling and searching activity of animals subdivided into two groups: "active" and "passive". After a 6-hour immobilization stress only in "passive" rats an increase of volumetric velocity of coronary flow; a decrease of an autoregulation index, coronary reserve against the background of intravascular pressure reduction, were found out. The blockade of nitric oxide synthesis in this group completely eliminated the stress-induced decrease of coronary vascular tone and essentially limited the caused by stress dissociation of coronary flow and the contractility function of the myocardium. In blood plasma of "passive" animals the nitrite/nitrate contents was by 55% more than of the "active" rats. After the transferred stress, in "passive" animals the nitrite/nitrate concentration in blood plasma increased by 29% and in "active" rats--by 136%; the absolute values, however, did not differ between the groups. Thus the autoregulation of coronary flow seems to be subject to action of stress in the rats showing a "passive" type of behaviour in the test "open field", and practically does not change in "active" animals; secondly, in spite of the fact that the stress-induced amplification of NO-producing function andothelium of coronary blood vessels is stereotyped in different rats, in "passive" rats, apparently, sensitivity of coronary vessels to nitric oxide is higher than at "active" those.
Solodkov
A P
AP
State Medical University, Belarus, Vitebsk 210023, 27 Frunze Ave.
Shcherbinin
I Iu
IIu
D000818:Animals; D003326:Coronary Circulation; D004730:Endothelium, Vascular / Q000378:metabolism; D005260:Female; D006706:Homeostasis; D007103:Immobilization; D066298:In Vitro Techniques; D009200:Myocardial Contraction; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052250:Nitric Oxide Synthase Type III; D051381:Rats; D013045:Species Specificity; D013315:Stress, Psychological / Q000503:physiopathology* / Q000523:psychology
D019001:Nitric Oxide Synthase; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat
K mekhanizmu razvitiia izmeneniĭ autoreguliatsii koronarnogo krovotoka u krys s razlichnoĭ chuvstvitel'nost'iu k stressu.