title: Organic cation secretion by Cancer borealis urinary bladder.
abstract: In the crab, Cancer borealis, initial clearance studies showed a potent renal excretory system for the model organic cation, tetraethylammonium (TEA). TEA clearance averaged 145 +/- 32 ml/day, which was 18 times the paired polyethylene glycol clearance. TEA uptake by slices of urinary bladder was concentrative, saturable, inhibitable by N1-methylnicotinamide chloride, and dependent on glycolytic, but not oxidative, metabolism. When mounted in flux chambers, bladders exhibited a large net secretory flux. For 0.1 mM TEA, the ratio of secretory to reabsorptive fluxes was 65. Urinary bladders from another crab, Cancer irroratus, and a lobster, Homarus americanus, also exhibited net TEA secretion. In C. borealis bladder, secretory transport was concentrative, saturable, and nearly abolished by addition of 1 mM quinine to the serosal bath. Reabsorptive transport was not concentrative and was not reduced by luminal quinine. The data are consistent with a secretory pathway that is transcellular and mediated by carriers at both the serosal and luminal membranes.
mesh_terms: D000818:Animals; D001692:Biological Transport; D003386:Brachyura; D002412:Cations; D004848:Epithelium / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D011092:Polyethylene Glycols / Q000378:metabolism; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000378:metabolism; D001743:Urinary Bladder / Q000502:physiology*
chemical_list: D002412:Cations; D013757:Tetraethylammonium Compounds; D011092:Polyethylene Glycols; D019789:Tetraethylammonium