Response of Human Sweat Glands to Local Heating

The responsiveness of sweat glands to locally applied heat was first reported by Saito (1) who observed sweating from the denervated foot-pad of the cat upon warming of the part, as well as localized thermal sweating in normal human skin. This response of human eccrine sweat glands was further characterized by Randall (2), Janowitz and Grossman (3) and Benjamin (4). The latter author studied the conditions of local temperature and environmental temperature and humidity which determine the response. In the several cited reports, the effects of a variety of locally applied blocking drugs were observed: reduction in the degree, or elevation in the threshold, of the response, but not its abolition, was produced with procaine, with atropine and hexamethonium. These findings, and the continued responsiveness of the glands after denervation (3), suggested that the thermal effect was, at least in part, independent of the innervation of the glands, whether this might be acting through a central or an axone reflex mechanism.