[Effect of temperature on the adrenoreactivity of the small intestine in the rat].

In isolated sections of the rat small intestine, adrenergic responses to phenylephrine (P), noradrenaline (NA) and isopropylnoradrenaline (IN) were studied at various temperatures of the incubation medium. Raise of the temperature from 33 to 37 degrees C increased the sensitivity of adrenoreceptors to P and NA 3.2-and 2.1-fold but did not change the sensitivity to IN. This change of adrenoreactivity was eliminated by phentolamine blockade of alpha-adrenoreceptors, and the raise of temperature always produced a decrease in maximal reaction of the small intestine. The change of adrenoreceptors of the small intestine smooth muscles seems to be related primarily to the rearrangement of alpha-adrenoreceptors.