title: Effect of angiotensin-converting enzyme inhibitor quadropril on dynamic parameters of vascular tone under conditions of NO synthesis blockade in normotensive and spontaneously hypertensive rats.
abstract: The role of NO in the mechanism of quadropril modulation of the flow-dependent vasodilation was examined in normotensive (Wistar) and spontaneously hypertensive (SHR) rats. The abdominal aorta was cannulated and autoperfused at different volume rates to obtain the pressure-flow curves. In the first experimental series, the blood flow-pressure dependence was measured before and after intravenous injection of quadropril (1 mg/kg). In the next series, this dependence was obtained before and after injection of NO-synthase inhibitor L-NNA (10 mg/kg) and quadropril, respectively. Quadropril potentiated vasodilation caused by an increase in perfusion volume rate in both normo- and hypertensive rats and stabilized intravascular pressure. Inhibition of NO synthesis elevated hydraulic resistance and decreased stability of intravascular pressure in normo- and hypertensive rats. In normotensive rats, these changes were promoted by a decrease in vascular distensibility. Under these conditions, quadropril pronouncedly potentiated the flow-dependent vasodilation only in SHR rats, which was revealed methodically by an increase in perfusion rate in the posterior quarter of the body. Thus, in SHR rats the quadropril-potentiated vasodilation in response to increased perfusion rate does not depend on NO synthesis.
authors.affiliation: V. A. Almazov Federal Center for Heart, Blood, and Endocrinology, St. Petersburg, Russia. sonin_d@mail.ru
authors.forename: D L
authors.initials: DL
authors.lastname: Sonin
authors.forename: M M
authors.initials: MM
authors.lastname: Galagoudza
authors.forename: A V
authors.initials: AV
authors.lastname: Syrensky
authors.forename: V A
authors.initials: VA
authors.lastname: Tsyrlin
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D004656:Enalapril / Q000031:analogs & derivatives* / Q000494:pharmacology; D006439:Hemodynamics / Q000187:drug effects*; D006973:Hypertension / Q000201:enzymology / Q000503:physiopathology*; D008297:Male; D009569:Nitric Oxide / Q000096:biosynthesis / Q000378:metabolism*; D051381:Rats; D011918:Rats, Inbred SHR; D017208:Rats, Wistar; D014655:Vascular Resistance / Q000187:drug effects; D014664:Vasodilation / Q000187:drug effects*; D019323:omega-N-Methylarginine / Q000494:pharmacology
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D004656:Enalapril; C052555:spirapril