Adaptive Changes in Sweat Gland Function

Abstract

Evidence has been presented that increased sweating function with acclimation to heat is attributed partly to adaptive changes in the periphery, especially in sweat gland function. Sweat output increases more at the extremities than at the trunk. Local sweat glands can be trained with repeated immersion of the area in hot water in unacclimatized individuals, but not any further in acclimatized persons. The process of gland training may be much slower during acclimation in which local heat stress is milder than that imposed by a hot water bath. It has also been suggested that adaptive changes are induced not by the repetitive experience of sweating but by the repetitive need to sweat. Repeated direct (chemical) stimulation of sweat glands appears to potentiate their function, but may rather exert an adverse effect on the function of the nerve ending. Women are inferior to men in adaptability of sweat glands, whereas in men adaptability is reduced more prominently with advancing age than in women. Reduction of sodium concentration in sweat with acclimation is attributable to increased sensitivity to aldosterone and is considered to form a part of adaptive increase in sweat gland function. Sweating response to heat load is rather reduced in long-term acclimatization to torrid climates, which resembles short-term acclimation to continuous heat. Whether adaptive changes occur in sweat glands remains to be investigated.