Sweat secretion by human axillary apoeccrine sweat gland in vitro

1987 ◽  
Vol 252 (1) ◽  
pp. R181-R187 ◽  
Author(s):  
K. Sato ◽  
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.

1983 ◽  
Vol 245 (2) ◽  
pp. R203-R208 ◽  
Author(s):  
K. Sato ◽  
F. Sato

The mechanisms underlying variations in perspiration rate at the glandular level are still poorly understood. Human eccrine sweat glands were dissected from the back of 12 adults, cannulated, and stimulated in vitro with methacholine (Mch). The maximal sweat rate and pKA for Mch determined from the dose-response curve for each individual were compared with the anatomic dimensions of the isolated secretory tubules. There was significant correlation between Mch sensitivity (pKA) and the size of the sweat gland, sweat rate per gland, sweat rate per unit length of the secretory tubule, and sweat rate per unit glandular volume. The sweat glands from individuals judged to be poor sweaters exhibited smaller size, lower secretory activity both in vivo and in vitro, and decreased Mch sensitivity compared with glands from physically fit individuals. We conclude that the increased Mch sensitivity and glandular hypertrophy are the two important features of functionally active sweat glands and infer that these parameters could improve as a result of acclimatization to physical exercise and/or heat.


1994 ◽  
Vol 86 (2) ◽  
pp. 133-139 ◽  
Author(s):  
K. Sato ◽  
S. Cavallin ◽  
K. T. Sato ◽  
F. Sato

1. Some of the basic functional features of the mouse paw eccrine sweat gland were delineated to allow comparison with those of transgenic mice in the future. 2. The mouse sweat secretory coil responds to methacholine, elaborating a K+-rich (> 120 mmol/l), Na+-poor (< 70 mmol/l) primary fluid as does the rat paw sweat gland, as previously reported. The methacholine-induced sweat rate increases with age in parallel with the growth of the sweat gland over the first 6 weeks of life. 3. The sweating response to cyclic AMP-elevating agents, such as isoprenaline or forskolin, is as much as 40% of the methacholine-induced sweat rate at 1 week of age, but falls to 10% by 6 weeks of age despite the fact that the agonist-induced tissue accumulation of cyclic AMP expressed on a per μg of protein basis triples with age over the same period. 4. A marked K+ outflux was also noted in response to methacholine and a small K+ outflux was seen in response to cyclic AMP-elevating agonists in super-fused adult mouse secretory coils in vitro. 5. Since sweat secretion is usually associated with activation of either K+ channels or Cl− channels or both, and since the sweating occurred in response to cyclic AMP-elevating agonists, we speculate that the cyclic AMP-activated Cl− channels (the mouse version of the cystic fibrosis transmembrane conductance regulator) may also occur in the mouse sweat gland, but that the degree of their expression may be influenced by the age of the mice.


1991 ◽  
Vol 260 (2) ◽  
pp. R314-R320 ◽  
Author(s):  
H. Yokozeki ◽  
T. Hibino ◽  
T. Takemura ◽  
K. Sato

Although cysteine proteinases have been reported to be present in human eccrine sweat, their endogenous inhibitors, cysteine proteinase inhibitors (CPIs), have remained unstudied. We now present evidence that CPIs are indeed a true ingredient of human eccrine sweat. Sweat induced in sauna was collected over a Vaseline barrier placed on the skin to minimize epidermal contamination. The absence of major epidermal contamination of the sweat was further ensured by monitoring an epidermal marker, high-molecular-mass aminopeptidase. Sweat CPI was purified sequentially by chromatography with Sephacryl S-200, carboxymethylated papain-Sepharose, and anion-exchange Mono Q fast-protein liquid chromatography columns. Sweat CPI has a molecular mass of approximately 15 kDa, is stable for temperature (up to 80 degrees C) and pH (from 3 to 10), and inhibits papain, ficin, and sweat cathepsin B- and H-like enzymes. Sweat CPI may be of sweat gland origin because 1) the rate of CPI output in sweat (CPI concentration x sweat rate) is constant over 45 min; 2) antibody against epidermal CPI, which cross-reacts with sweat CPI, localized immunoreactivity in the sweat duct; 3) CPI activity was present in the glandular extracts of control and methacholine-stimulated (for 1 h in vitro) human sweat glands; and 4) the peaks of CPI activity in the glandular extract and sweat CPI were both eluted (by high-pressure liquid chromatography) at around 15 kDa. Sweat CPI may be very similar to epidermal CPI (which belongs to the stefin family of CPIs) because of many shared characteristics. The identity and function of sweat CPI remain to be studied.


1981 ◽  
Vol 241 (3) ◽  
pp. C113-C120 ◽  
Author(s):  
K. Sato ◽  
F. Sato

The role of Ca2+ in eccrine sweat secretion was studied using isolated cannulated monkey palm eccrine sweat glands in vitro. Removal of Ca2+ from the incubation medium promptly abolished sweat secretion induced by methacholine or phenylephrine. In contrast, isoproterenol-induced sweat secretion lasted from 40 to 220 min in a Ca2+-free medium. The methacholine-induced maximal sweat rate was a hyperbolic function of the Ca2+ concentration in the bath and reached a plateau at 1 mM Ca2+. Higher Ca2+ concentrations rather suppressed the secretory rate. The Ca2+ ionophore A23187, but not X537A, at 3 X 10(-6) M induced copious prolonged sweat secretion after a latent period of 10 min. A23187-induced sweat secretion was not inhibited by either atropine or propranolol. D 600 (methoxyverapamil) at 10(-3) M inhibited sweat secretion induced by methacholine or by isoproterenol, although the latter lasted longer than methacholine sweating (20 vs. 5 min) in the presence of D 600. The data support the notion that Ca2+ influx into the cell plays a crucial role in cholinergic and alpha-adrenergic sweating, whereas a partial supply of Ca2+ for isoproterenol-induced sweating is derived from an intracellular store.


1979 ◽  
Vol 237 (3) ◽  
pp. C177-C184 ◽  
Author(s):  
K. Sato ◽  
A. Nishiyama ◽  
M. Kobayashi

Contractile properties of an isolated segment of the secretory coil of the monkey palm eccrine sweat gland were studied in vitro with a transducer. Contraction of up to 10 mgf was induced with acetylcholine but not with alpha or beta adrenergic agonists, caffeine, prostaglandin E1, or by a calcium ionophore A23187. Other features included K+ contracture, staircase effect, poor extensibility, length-tension relationship with a peak tensile response at 115--120% of the resting length, and requirement of Ca2+. The function of myoepithelium is unlikely to expulse the preformed sweat because the amount of preformed sweat is small, K+-contracture failed to expulse sweat, and because myoepithelial contraction was not induced by such stimulants of sweat secretion as A23187, phenylephrine, isoproterenol, and prostaglandin E1. The maximal transverse tension of 20 mgf during acetylcholine stimulation under resting tension was calculated to support the luminal hydrostatic pressure of approximately 500 mmHg. Thus the function of the myoepithelium may be to render structural support for the secretory epithelium.


1981 ◽  
Vol 240 (1) ◽  
pp. R44-R51 ◽  
Author(s):  
K. Sato ◽  
F. Sato

Pharmacologic responsiveness of the eccrine sweat gland has never been studied under well-defined in vitro experimental conditions. Using isolated cannulated single monkey palm eccrine sweat glands, the dose response to both cholinergic and alpha- and beta-adrenergic agents and the effects of various antagonists on agonists were studied. The maximal sweat rate was highest after stimulation with cholinergic agonists, was lower with the beta-adrenergic agonist, and was least with the alpha-adrenergic agonist. Each secretory response was inhibited by its specific antagonist. Attempts to demonstrate the spare receptor, if any, by means of preincubation of the glands with N-(2-chlorethyl)dibenzylamine (Dibenamine) were unsuccessful. From the hyperbolic dose-response curves the values for KA and KB, dissociation constants for agonists and antagonists, respectively, were thus tentatively estimated according to Clark's classical receptor theory. Schild plots for each agonist-antagonist interaction produced straight lines with slopes of near unity, indicating the adequacy of the methodology. It was concluded that the isolated eccrine sweat glands retain their pharmacologic viability in vitro and show responsiveness to cholinergic as well as both alpha- and beta-adrenergic stimulations.


1984 ◽  
Vol 247 (3) ◽  
pp. C234-C239 ◽  
Author(s):  
K. Sato ◽  
F. Sato

The possibility that guanosine 3'5'-cyclic monophosphate (cGMP) may be an intracellular mediator of cholinergic stimulation [methacholine chloride (MCh)] was explored by comparing the relationship between the time course of cGMP accumulation and sweat secretion by use of isolated monkey palm eccrine sweat glands. Isolated sweat glands were incubated with MCh or other agents, and tissue levels of cGMP were determined by radioimmunoassay. In parallel experiments, sweat secretion was induced from cannulated single sweat glands in vitro. Stimulation with MCh produced a Ca-dependent transient elevation of cGMP level from 10 to 80 fmol/gland, peaking at 1-2 min but returning to the basal level by 5 min. The MCh-induced cGMP level was dose dependent and was inhibited by atropine. Ionophore A23187 (2 X 10(-4) M), however, caused persistent elevation of cGMP level for at least 20 min. Neither 10(-4) M MNNG, which elevated the cGMP level comparably with MCh stimulation, nor 8-bromo-cGMP (2 mM) induced sweat secretion. Thus although a parallelism between the cGMP level and sweating rate appears to hold for the initial stage of MCh-induced sweating, it does not hold for the steady state of sweat secretion. Data could not be interpreted to favor the notion that cGMP may be the intracellular mediator of cholinergic sweat secretion.


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