Membrane potential of rat urinary bladder epithelial cells.
Rat urinary bladder epithelial cells exhibited a membrane potential of about -22 (apical) and -24 (basal) mV in normal Krebs solution. Blockade of Na+ entry through the apical membrane by Na+ depletion of administration of amiloride, or inactivation of the Na pump in the basal membrane by ouabain resulted in marked hyperpolarization of the epithelial cells. N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN), a specific carcinogen, and saccharin, a potent enhancer of carcinogenesis, inhibited development of the Na+ channel and/or Na pump on the bladder epithelium. This physiology may contribute to the abnormal intracellular environment leading to bladder carcinoma.
D000818:Animals; D002085:Butylhydroxybutylnitrosamine / Q000494:pharmacology; D004848:Epithelium / Q000187:drug effects / Q000502:physiology; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D051381:Rats; D011916:Rats, Inbred F344; D012439:Saccharin / Q000494:pharmacology; D001743:Urinary Bladder / Q000187:drug effects / Q000502:physiology*
D002085:Butylhydroxybutylnitrosamine; D012439:Saccharin