AJP - Regulatory, Integrative and Comparative Physiology, Vol 252, Issue 1 181-R187, Copyright © 1987 by American Physiological Society
Sweat secretion by human axillary apoeccrine sweat gland in vitro
K. Sato and F. Sato
Functional characteristics of isolated single human axillary apoeccrine
sweat glands have been studied using in vitro sweat induction methods.
Sustained copious clear fluid secretion was evoked by methacholine (MCh),
epinephrine (EP), isoproterenol (ISO), and phenylephrine (PL) in decreasing
order in a pharmacologically specific manner. Apoeccrine glands showed a
higher cholinergic sensitivity than eccrine sweat glands, as shown by the
apparent association constant for MCh of 2.7 X 10(-7) M compared with 2.1 X
10(-6) M for the axillary eccrine sweat gland. The average total sweat rate
of the apoeccrine gland for a 30-min period was sevenfold higher than that
of the eccrine sweat gland. In contrast, isolated apocrine glands showed
intermittent pulsatile turbid sweat secretion in response to MCh or EP. The
Na+ and K+ concentration of apoeccrine glands was nearly isotonic, whereas
those of apocrine sweat was 120-140 mM for Na+ and 10-20 mM for K+.
Apoeccrine ductal Na+ absorption was also observed in the apoeccrine glands
and was no more efficient than that of the axillary eccrine sweat gland.
Thus apoeccrine sweat glands are functionally and pharmacologically
distinct from axillary apocrine glands and significantly contribute to
overall axillary sweating in humans.
