AJP - Regulatory, Integrative and Comparative Physiology, Vol 266, Issue 3 950-R959, Copyright © 1994 by American Physiological Society
Interleukin-1 alpha in human sweat is functionally active and derived from the eccrine sweat gland
K. Sato and F. Sato
Marshall Dermatology Research Laboratories, Department of Dermatology, University of Iowa College of Medicine, Iowa City 52242-1181.
We wished to establish the presence of interleukin-1 (IL-1) in human sweat
(5) and clarify its origin and mechanism of secretion. IL-1 alpha
concentration ([IL-1 alpha]) in clean sweat from the back increased with
the sweat rate, plateauing at the maximal sweat rate ([IL-1 alpha]max). The
mean [IL-1 alpha]max was 545 pg/ml (n = 17) for men and 1,324 pg/ml for
women in back sweat. The mean [IL-1 alpha]max for axillary sweat in men was
1,568 (n = 6). Palmar sweat was 9.2 ng/ml (n = 5) for IL-1 alpha and 7.9
ng/ml for IL-1 beta. [IL-1 alpha]max decreased to one-third that of the
first sweat test, when second sauna sweat tests were conducted after 2 h of
continuous sweating on the same day. Western blot analysis of the purified
sweat IL-1 alpha fraction revealed bands at 17, 29, and 33 kDa.
Immunoreactive IL-1 alpha was localized mainly in the secretory coil lumen,
intercellular canaliculi, cytoplasm, mitochondria, and near plasma
membranes. Polymerase chain reaction revealed the presence of IL-1 alpha
mRNA in the sweat gland and in cultured human eccrine secretory coil cells.
Both sweat IL-1 alpha and human recombinant IL-1 alpha at 500 pg/ml
strongly stimulated interleukin-6 and interleukin-8 production in cultured
fibroblasts. We conclude that the IL-1 alpha-like immunoreactive substance
in sweat is IL-1 alpha itself, is derived from the sweat gland, and is
biologically active at concentrations normally present in fresh sweat.
