title: Effect of aging and chronic angiotensin I converting enzyme inhibition on the endothelial function of the mesenteric arterial bed of the rat.
abstract: Endothelial function was studied in perfused mesenteric arterial bed preparations removed from 6, 12, 24, or 30 month-old, male, normotensive rats. Half of the animals were treated with a hypotensive dose of an angiotensin I converting enzyme (ACE) inhibitor (perindopril, 1 mg/kg/day, p.o.) from 6 months onwards. Disruption of endothelium produced a fall in baseline perfusion pressure in all animals except 30-month old controls, suggesting that the maintenance of baseline tone by endothelial vasoconstrictor(s) is impaired with age. Physiologic antagonism of norepinephrine-induced vasoconstriction by the muscarinic agonist carbachol was impaired in 30-month old controls. Norepinephrine-induced vasoconstriction increased following disruption of endothelium, suggesting that norepinephrine-induced release of endothelium-derived relaxing factor attenuates vasoconstriction. This mechanism was impaired in 30-month old controls. Chronic ACE inhibition postponed the age-related decrease in vasodilator and vasoconstrictor endothelial functions, either directly or indirectly via the hypotensive action of such treatment.
mesh_terms: D000375:Aging / Q000502:physiology*; D000704:Analysis of Variance; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D009569:Nitric Oxide / Q000378:metabolism; D020913:Perindopril; D051381:Rats; D011919:Rats, Inbred Strains; D014661:Vasoconstriction / Q000187:drug effects
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D000959:Antihypertensive Agents; D007211:Indoles; D009569:Nitric Oxide; D020913:Perindopril