ION-TRANSPORT IN PRIMARY CULTURES FROM HUMAN SWEAT GLAND COILS STUDIED WITH X-RAY-MICROANALYSIS

Chloride secretion in primary cultures of cells originating from om th e secretory coil of human sweat glands was investigated by electron pr obe X-ray microanalysis. The total intracellular CI concentration was lowered by muscarinic agonists (carbachol and acetylcholine), as well as by the calcium ionophore A23187. The muscarinic agonists also lower ed the cellular K concentration. Cl- secretion induced by these agonis ts could be inhibited by the chloride channel blocker NPPB. After cAMP stimulation, the frequency distribution of the Cl concentration chang ed from Gaussian to bimodal, indicating that cAMP induces Cl- secretio n only from a subpopulation of the cells. Also ATP stimulated Cl- secr etion, indicating the presence of purinergic receptors. The results su ggest that some of the cells in addition to Ca2+-regulated Cl- channel s also possess cAMP-activated Cl- channels. Hence, the primary culture s still possess the Cl- transport mechanisms known to be present in in tact glands. It can, however, not be excluded that some coil cells hav e acquired ductal characteristics during culture.