Mack GW, Smith BS, Rowland B. TEA-sensitive K
+ channels and human eccrine sweat gland output.
J Appl Physiol (1985) 2019;
127:921-929. [PMID:
31465715 DOI:
10.1152/japplphysiol.00308.2019]
[Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Cholinergic-activated sweating depends on an influx of Ca2+ from extracellular fluid. It is thought that the opening of K+ channels on secretory epithelial cells facilitates Ca2+ entry. We examined the hypothesis that tetraethylammonium (TEA)-sensitive K+ channels participate in sweat production. We used a pre-post experimental design and initiated cholinergic-mediated sweating with intradermal electrical stimulation, monitored local sweat rate (SR) with a small sweat capsule mounted on the skin, and delivered 50 mM TEA via intradermal microdialysis. Local SR was activated by intradermal stimulation frequencies of 0.2-64 Hz, and we generated a sigmoid-shaped stimulus-response curve by plotting the area under the SR-time curve versus log10 stimulus frequency. Peak local SR was reduced from 0.372 ± 0.331 to 0.226 ± 0.190 mg·min-1·cm-2 (P = 0.0001) during application of 50 mM TEA, whereas the EC50 and Hill slopes were not altered. The global sigmoid-shaped stimulus-response curves for control and 50 mM TEA were significantly different (P < 0.0001), and the plateau region was significantly reduced (P = 0.0023) with the TEA treatment. The effect of TEA on peak local SR was similar in male and female subjects. However, we did note a small effect of sex on the shape of the stimulus-response curves during intradermal electrical stimulation. Overall, these data support the hypothesis that cholinergic control of sweat gland activity is modulated by the presence of TEA-sensitive K+ channels in human sweat gland epithelial cells.NEW & NOTEWORTHY The contribution of various potassium channels to the process of cholinergic-mediated human eccrine sweat production is unclear. Using a novel model for cholinergic-mediated sweating in humans, we provide evidence that tetraethylammonium-sensitive K+ channels (KCa1.1 and Kv channels) contribute to eccrine sweat production.
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