The effect of temperature on the sensitivity to noradrenaline of isolated perfused ear and mesenteric arteries of ox, sheep and pig.

RESPONSES to graded doses of noradrenaline were obtained from isolated perfused arteries of the ox, sheep and pig at 38-39, 35, 30, 20 and 10°C. The sensitivity of ox and sheep ear arteries from animals exposed to an environmental temperature of approximately 5°C was maximal at 20°C. The sensitivity of ox and sheep mesenteric arteries was maximal at 38-39°C, as was the sensitivity of ear arteries from pigs exposed to an environmental temperature of 27°C.It is suggested that the temperature at which isolated mammalian arteries show maximal sensitivity to noradrenaline may be related to the local temperature to which they were previously exposed in the intact animal.