AS PART of an investigation into the physiologic competence of the sweating mechanism in newborn infants, we have been studying local sweating responses to intradermally injected sudorific drugs having different modes of action.
In a recently reported first test series,1 we tested the responsiveness of neonates to epinephrine (Adrenaline) hydrochloride and to the muscarinic action of acetylcholine, stimuli which are believed to act directly on the receptors of the sweat glands.2-8 Full term infants, 1 to 7 days old, were found to be highly responsive to both drugs, while the glands of prematurely born infants of corresponding age were significantly less reactive, or refractory.
The present report deals with local stimulation tests employing nicotine, the most effective of those agents which excite local sweating indirectly by initiation of the sudomotor axon reflex. By definition, axon reflex responses are transmitted over pathways involving solely the peripheral ramifications of a