To model sweat gland fluid secretion <I>in vitro</I>, human apocrine glands were isolated from axillary skin and their secretory coil cells were cultured and mounted in an Ussing chamber. Cultured apocrine coil cells exhibited an amiloride-sensitive inward resting short circuit current, suggesting an absorptive phenotype. However, evidence of a chloride-secretory phenotype was also observed: transient inward currents were recorded in response to autonomic secretagogues and inflammatory mediators, and these were not abolished by amiloride, but they were reduced by half in chloride-free buffer. This may indicate a role for chloride secretion in mediating the stimulated currents. Further, sustained inward currents were recorded in 58% of tissues which were attenuated by frusemide, implying the involvement of the Na<SUP>+</SUP>/K<SUP>+</SUP>/Cl<SUP>-</SUP> transporter. Assuming that secondary active chloride transport is responsible for aqueous fluid secretion in the apocrine sweat gland, these data are compatible with some maintenance of an <I>in vivo</I> phenotype in culture. To study the cellular determinants of eccrine sweat gland differentiation, eccrine sweat gland-associated fibroblasts were cultured and compared with derminal fibroblasts from the same subject, demonstrated a different pattern of outgrowth and proliferation. Therefore these cells may represent a novel fibroblast subtype. To improve the differentiation of eccrine sweat gland coil cells <I>in vitro</I>, they were co-cultured with eccrine fibroblasts. Eccrine sweat gland cells grown on a Transwell as a control demonstrated apparent dedifferentiation to a reabsorptive phenotype, indicated by the amiloride-sensitivity of their resting and agonist-stimulated inward short circuit currents. Eccrine cells co-cultured with eccrine fibroblasts, however, demonstrated agonist-stimulated outward currents in the presence of amiloride.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:598614 |
| Date | January 1997 |
| Creators | Dove, N. S. |
| Publisher | University of Cambridge |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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