Hormone effects on transport in cultured epithelia with high electrical resistance.
Three continuous lines of amphibian epithelial cells form epithelia with a high transepithelial resistance (greater than 4,000 omega . cm2) in culture. The cell lines are TB-M and TB-6c, derived from the urinary bladder of Bufo marinus, and A6, derived from the kidney of Xenopus laevis. Short-circuit current is equivalent to net mucosa-to-serosa sodium transport in two cell lines and slightly exceeds sodium transport in epithelia formed by TB-6c cells. None of the cell lines has an adenylate cyclase response or a transport or permeability response to vasopressin. Water permeability is low in all three cell lines and is not affected by adenosine 3',5'-cyclic monophosphate (cAMP). In the three lines of cells, cAMP and aldosterone each increases short-circuit current with a time course similar to that seen in naturally occurring epithelia. In contrast to the toad urinary bladder and epithelia of line TB-M in which the aldosterone stimulation of short-circuit current is associated with a fall in transepithelial resistance, there is no change in resistance across epithelia of lines TB-6c and A6. There is also a striking difference in the sensitivity of the three lines to inhibition of short-circuit current by amiloride.
D000450:Aldosterone / Q000494:pharmacology; D000584:Amiloride / Q000494:pharmacology; D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002024:Bufo marinus; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism*; D007668:Kidney; D008564:Membrane Potentials / Q000187:drug effects; D012964:Sodium / Q000378:metabolism*; D013997:Time Factors; D001743:Urinary Bladder; D014667:Vasopressins / Q000494:pharmacology; D014982:Xenopus laevis
D014667:Vasopressins; D000450:Aldosterone; D000584:Amiloride; D012964:Sodium; D000242:Cyclic AMP