Norepinephrine release in isolated arteries induced by K-free solution.
Helical strips from arteries with a rich sympathetic innervation (rat tail and femoral, and dog mesenteric arteries) develop a sustained contracture when exposed to a K-free physiological salt solution (PSS). The contracture can be blocked by phentolamine and does not occur in arteries whose nerve terminals have been destroyed with 6-hydroxydopamine. The temporal relationship between force development and efflux of NE was determined. Helical strips of rat tail arteries or dog mesenteric arteries were incubated in PSS containing 1-norepinephrine-7-3H([3H]NE). They were then transferred to a superfusion system which allowed isometric recordings and collection of the superfusate for the estimation of [3H]NE content. Following exposure to a K-free PSS force development paralleled NE release and both parameters were potentiated by ouabain. These data demonstrate that this neurogenic mechanism plays a most important role in the K-free contracture of the vascular smooth muscle studied. It is in accord with the observation that NE is released by adrenergic nerves following inhibition of Na+-K+-ATPase.
D000818:Animals; D001158:Arteries / Q000378:metabolism*; D002118:Calcium / Q000494:pharmacology; D004285:Dogs; D005263:Femoral Artery / Q000378:metabolism; D006892:Hydroxydopamines / Q000494:pharmacology; D008345:Manganese / Q000494:pharmacology; D008638:Mesenteric Arteries / Q000378:metabolism; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D009411:Nerve Endings / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism* / Q000502:physiology; D010042:Ouabain / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D011188:Potassium; D051381:Rats; D013564:Sympathetic Nervous System / Q000502:physiology; D013623:Tail / Q000098:blood supply
D006892:Hydroxydopamines; D008345:Manganese; D010042:Ouabain; D011188:Potassium; D002118:Calcium; D009638:Norepinephrine; D010646:Phentolamine