title: Effect of periglandular ionic composition and transport inhibitors on rhesus monkey eccrine sweat gland function in vitro.
abstract: 1. The effects of peritubular ions and transport inhibitors were studied on methacholine (MCH)-induced sweat secretion by the isolated, cannulated monkey palm sweat glands in vitro and on the transepithelial and basolateral membrane potential (p.d.). 2. Sweat secretory rate was a curvilinear function of peritubular Na+ and Cl- concentration. Among the anion substitutes only Br- was able to totally substitute for Cl-. Presence of HCO3- or H2PO4- in the bath was not essential. 3. Both bumetanide and furosemide inhibited sweat secretion in a dose-dependent manner with the median effective concentration (EC50) of 3 X 10(-6) and 3 X 10(-5) M, respectively. 4. Bumetanide (10(-4) M) had no significant effect on basolateral membrane p.d. but nearly abolished the transepithelial p.d. 5. Hydrochlorothiazide (HCTZ, 3 X 10(-4) M) inhibited sweat secretion by only 35%. Inhibitors of ion exchangers amiloride (10(-4) M) and DIDS (4,4'-diisothiocyanostilbene-2,2'-disulphonic acid, 10(-4) M) lowered sweat secretion by less than 20%. 6. Removal of peritubular K+ as well as addition of 5 mM-Ba2+ also inhibited sweat rate. 5 mM-Ba2+ abolished the transepithelial p.d. and depolarized the basolateral p.d. by 26 mV, although the effects of Ba2+ on sweating and the transepithelial p.d. were only transient. 7. The data raise a possibility that either the NaCl or Na+-K+-2Cl- co-transport system or both may be involved in MCH-induced sweat secretion, whereas the role of parallel ion exchangers, if any, may be rather minor.
mesh_terms: D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000838:Anions / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D002412:Cations / Q000494:pharmacology; D002712:Chlorides / Q000502:physiology; D004232:Diuretics / Q000494:pharmacology; D004439:Eccrine Glands / Q000502:physiology*; D066298:In Vitro Techniques; D007473:Ion Channels / Q000502:physiology*; D008253:Macaca mulatta; D011188:Potassium / Q000494:pharmacology; D012636:Secretory Rate / Q000187:drug effects; D012964:Sodium / Q000502:physiology; D013542:Sweat / Q000378:metabolism*; D013545:Sweat Glands / Q000502:physiology*
chemical_list: D000838:Anions; D002412:Cations; D002712:Chlorides; D004232:Diuretics; D007473:Ion Channels; D012964:Sodium; D011188:Potassium