Responses of isolated rabbit ear arteries to intra- and extraluminal L- and D-noradrenaline, L-adrenaline and histamine in the temperature range 37-3 degrees C.

Abstract

While the sensitivity of perfused rabbit ear arteries to intraluminal L- and D-noradrenaline and histamine fell markedly between 37 and 3°C, their sensitivity to extraluminal L-noradrenaline was similar at these 2 temperatures. This maintenance of response is attributed to cold blockade of uptake by nerve terminals around the media of the artery, so that a much higher proportion of the extraluminal noradrenaline reaches the smooth muscle cells, thereby compensating for a fall in sensitivity of the cells.