Endothelium-derived hyperpolarizing factor as an in vivo back-up mechanism in the cutaneous microcirculation in old mice.

摘要: There is now strong evidence that an endothelium-derived hyperpolarizing factor (EDHF), other than nitric oxide (NO) or prostaglandin (PG), exists for dilating arteries and arterioles. In vitro studies on isolated vessels pointed out a role EDHF as back-up mechanism when the NO pathway impaired, but there was lack of in vivo showing functional EDHF. Ageing has pronounced effects vascular function particularly endothelium-dependent relaxation, providing novel situation which to assess contributions The purpose present study thus determine if, vivo, cutaneous microcirculation ageing process. We investigated contribution each endothelial (NO, PG EDHF) vasodilatation induced by iontophoretic delivery acetylcholine local pressure application young adult (6–7 months) old (22–25 mice, using pharmacological inhibitors. vasodilator responses were dependent upon pathways whereas they EDHF-dependent mice. appears serve reaches pathological states terms ability relax microvessels, allowing persistent vasodilatator However, mechanism, did not completely restore vasodilatation, since reduced mice compared