title: Effect on Mn2+ on permeability properties of frog skin.
abstract: Mn2+ added to the inner bathing solution of frog skin caused a transient increase in potential difference (PD) and a decrease in total skin conductance and mannitol influx. Net Na flux and short-circuit current (Is. c.) were also reduced, the isotopic net flux being reduced more than Is. c. This observed discrepancy appears to be the result of Cl- retention in the outer medium since it was not observed when the skin was bathed in a sulfate-substituted chloride-free solution. The effect of Mn2+ on the inner side of the frog skin appears to be due to a reduced permeation of Na+ and Cl- through the outer barrier of the skin. Addition of Mn2+ to the outer solution bathing the frog skin caused an increase in PD and a smaller increase in Is. c. These changes were not associated with alterations in the fluxes of Na+ or mannitol and were observed only when chloride was present in the bathing solutions. The effect of Mn2+ on this side of the frog skin may therefore be due to a net retention of Cl- in the outer solution.
mesh_terms: D000818:Animals; D001001:Anura; D001693:Biological Transport, Active / Q000187:drug effects; D004553:Electric Conductivity; D066298:In Vitro Techniques; D008345:Manganese / Q000494:pharmacology*; D008353:Mannitol / Q000378:metabolism; D008564:Membrane Potentials; D010539:Permeability; D011898:Ranidae; D012867:Skin / Q000187:drug effects; D012879:Skin Physiological Phenomena; D012964:Sodium / Q000378:metabolism
chemical_list: D008353:Mannitol; D008345:Manganese; D012964:Sodium