Response of the cat's pad eccrine sweat glands to intravascular injections of catecholamines.

1. Using a sensitive method for detecting and monitoring sweat secretion, a study has been made of the effects of adrenaline and noradrenaline on the cat's pad sweat gland activity in the anaesthetized cat.2. Intravenous or intra-arterial injections of adrenaline or noradrenaline only very occasionally caused these glands to secrete.3. The predominant effect of these drugs on glands which are already secreting in response to plantar nerve stimulation is inhibitory.4. The catecholamine inhibition could be reduced or blocked by phentolamine, but not by propranolol, dibenamine or phenoxybenzamine.5. It is concluded that these glands can be directly activated by intravascular injections of adrenaline or noradrenaline, but that the inhibitory effect of concomitant vasoconstriction usually prevents a response being detected at the skin surface.