title: Aldosterone and chloride conductance of amphibian skin.
abstract: Chloride influx (JCl) across the skin of toads maintained in dilute MgCl2 or Na2SO4 was determined after overnight incubation with(out) aldosterone, and related to mitochondria-rich cell (MRC) density of the preparations. Adaptation to MgCl2 vs. Na2SO4 was reflected by higher plasma aldosterone in the former group (17 vs. 3 nmol/l, respectively) while JCl was lower, even after overnight incubation (172 vs. 318 pmol cm-2 s-1). Incubation with aldosterone induced a more pronounced increase in JCl in the case of Na2SO4- vs. MgCl2-adapted toads (delta JCl: 242 vs. 25 pmol cm-2 s-1, respectively), which could be related to difference in MRC density between these two groups (1078 vs. 615 cells/mm2, respectively). On the other hand, the in vitro effect of aldosterone on Na+ transport (assessed by Isc) was equally pronounced in both groups, and thus independent of MRC density. These data suggest that aldosterone, rather than being involved in MRC proliferation, stimulates Cl- conductance by influencing the functional state of MRC.
authors.affiliation: Department of Physiology, U.C.L. Medical School, Brussels, Belgium.
authors.forename: O
authors.initials: O
authors.lastname: Devuyst
authors.forename: V
authors.initials: V
authors.lastname: Beaujean
authors.forename: J
authors.initials: J
authors.lastname: Crabbé
mesh_terms: D000450:Aldosterone / Q000494:pharmacology*; D000818:Animals; D002024:Bufo marinus; D002455:Cell Division / Q000187:drug effects; D002712:Chlorides / Q000378:metabolism*; D004553:Electric Conductivity / Q000187:drug effects; D005110:Extracellular Space / Q000187:drug effects; D015636:Magnesium Chloride; D008564:Membrane Potentials / Q000187:drug effects; D012867:Skin / Q000187:drug effects / Q000378:metabolism*; D012964:Sodium / Q000378:metabolism*; D012965:Sodium Chloride; D013431:Sulfates
chemical_list: D002712:Chlorides; D013431:Sulfates; D015636:Magnesium Chloride; C012036:sodium sulfate; D012965:Sodium Chloride; D000450:Aldosterone; D012964:Sodium