title: Effects of aging and hypertension on the participation of endothelium-derived constricting factor (EDCF) in norepinephrine-induced contraction of rat femoral artery.
abstract: Endothelium-dependent contraction elicited by high concentrations of acetylcholine was described in hypertensive as well as in aged normotensive rats. The contribution of endothelium-derived constricting factor (EDCF) to norepinephrine-induced contraction is still unknown. We aimed to compare EDCF participation to norepinephrine-induced arterial contraction in spontaneously hypertensive rats (SHR) and aged normotensive Wistar-Kyoto (WKY) rats. Femoral arteries from either adult (7-months-old) or aged (14-months-old) animals were placed in myograph and norepinephrine-induced concentration-response curves were recorded under control conditions and in the presence of indomethacin (cyclooxygenase inhibitor, 10(-5) mol/l) or L-NNA (NO synthase inhibitor, 10(-4) mol/l) or both. Norepinephrine-induced concentration-response curve was enhanced in SHR compared to WKY rats, but concentration-response curve of aged WKY rats was similar to those of adult SHR. Cyclooxygenase inhibition largely attenuated concentration-response curves in all groups. However, this effect was greater in aged WKY rats and adult SHR compared to adult WKY rats. NO synthase inhibition augmented norepinephrine-induced contraction in arteries of adult WKY rats, but not in arteries from aged WKY rats or adult SHR. The combined administration of L-NNA and indomethacin had no additive effects on concentration-response curves. EDCF contribution to norepinephrine-induced contractions of arteries was considerably greater in adult SHR (80±3%) and aged WKY rats (86±2%) compared to adult WKY rats (35±10%). The inhibition of NO synthase augmented EDCF contribution to norepinephrine-induced contraction only in arteries from adult WKY rats (76±9%). We conclude that EDCF contribution to norepinephrine-induced contraction of conduit arteries is similarly enhanced in adult hypertensive and aged normotensive rats.
authors.forename: Silvia
authors.initials: S
authors.lastname: Líšková
authors.affiliation: Center of Cardiovascular Research and Institute of Physiology, Academy of Sciences of Czech Republic, Prague, Czech Republic. silvia.liskova@gmail.com
authors.forename: Líšková
authors.initials: L
authors.lastname: Silvia
authors.forename: Miriam
authors.initials: M
authors.lastname: Petrová
authors.forename: Petrová
authors.initials: P
authors.lastname: Miriam
authors.forename: Petr
authors.initials: P
authors.lastname: Karen
authors.forename: Karen
authors.initials: K
authors.lastname: Petr
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Kuneš
authors.forename: Kuneš
authors.initials: K
authors.lastname: Jaroslav
authors.forename: Josef
authors.initials: J
authors.lastname: Zicha
authors.forename: Zicha
authors.initials: Z
authors.lastname: Josef
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000375:Aging / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D016232:Endothelins / Q000378:metabolism*; D005263:Femoral Artery / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology*; D006973:Hypertension / Q000378:metabolism / Q000503:physiopathology*; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors; D009638:Norepinephrine / Q000494:pharmacology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D051381:Rats; D014661:Vasoconstriction / Q000187:drug effects*
chemical_list: D016861:Cyclooxygenase Inhibitors; D016232:Endothelins; D019001:Nitric Oxide Synthase; D011451:Prostaglandin-Endoperoxide Synthases; D000109:Acetylcholine; D009638:Norepinephrine; D007213:Indomethacin