Temperature changes produced by the injection of catecholamines and 5‐hydroxytryptamine into the cerebral ventricles of the conscious mouse

Abstract

Changes in temperature were determined following injection of noradrenaline, adrenaline, iso-prenaline, dopamine and 5-hydroxytrptamine (5-HT) [norepinephrine] into the cerebral ventricles of the conscious mouse. Noradrenaline [epinephrine] (1-20 Mg) and dopamine (10-160 [mu]g) caused falls in body temperature. Adrenaline [epinephrine] (1-20 Mg) caused a slight and transient rise in body temperature followed by a fall. Isoprenaline (5-20 [mu]g) caused a rise in body temperature, hypothermia only occurring after very high doses (200 [mu]g) of this catecholamine. a- and 0-adrenergic blocking agents, phentolamine (> 2 Mg) and propranolol ( 5 Mg) respectively, caused falls in body temperature when injected into the cerebral ventricles of the mouse. Specific drug antagonism studies were limited owing to the intrinsic effects of the [alpha]- and [beta]-adrenergic blocking agents. However, some evidence was obtained to indicate that noradrenaline mediated its effects through a central [alpha]-type adrenergic receptor. 5-HT (10-160 Mg) caused a fall in body temperature. The action of this indoleamine and the catecholamines in regard to thermoregulatory function is discussed.