title: Stimulatory and inhibitory effects of sulfhydryl reagent on p-aminohippuric acid transport by isolated renal tubules.
abstract: Isolated tubules from rabbit kidney cortex were treated with several different sulfhydryl reagents in an attempt to determine whether sulfhydryl groups are involved in organic acid transport. Disulfide reagents such as sodium tetrathionate and 6,6'-dithionicotinic acid were found to exert a biphasic effect on p-aminohippuric acid transport, i.e. transient stimulation followed by inhibition. In contrast, treatment of tubules with the mercaptide-forming reagent, p-chloromercuribenzoate, caused only inhibition of organic acid transport. Treatment of tubules with reductants such as dithiothreitol or mercaptoethanol blocked the stimulatory effect of tetrathionate without affecting the inhibitory effect of this oxidant. The inhibition caused by p-chloromercuribenzoate, however, was largely reversible when tubules were treated with reductants. The results suggest that the renal organic acid transport system contains sulfhydryl groups and that its activity is increased when some of these groups are oxidized.
mesh_terms: D000818:Animals; D001693:Biological Transport, Active; D002729:Chloromercuribenzoates / Q000494:pharmacology; D066298:In Vitro Techniques; D007684:Kidney Tubules / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D009539:Nicotinic Acids / Q000031:analogs & derivatives / Q000494:pharmacology; D011817:Rabbits; D012964:Sodium / Q000378:metabolism; D013439:Sulfhydryl Reagents / Q000494:pharmacology*; D013776:Tetrathionic Acid / Q000494:pharmacology; D010130:p-Aminohippuric Acid / Q000378:metabolism
chemical_list: D002729:Chloromercuribenzoates; D009539:Nicotinic Acids; D013439:Sulfhydryl Reagents; D013776:Tetrathionic Acid; D012964:Sodium; D010130:p-Aminohippuric Acid