title: Renal transtubular transport of mercapturic acid in vivo.
abstract: When S-benzyl-N-acetyl-L-[U-14C]cysteine, a mercapturic acid, was administered to rats intravenously, the plasma level of radioactivity decreased very rapidly with a concomitant increase in the renal level of radioactivity. The renal radioactivity reached its maximum within 2 min and then decreased rapidly with concomitant appearance of the radioactive mercapturic acid in the urine. Bilateral ligation of the ureters resulted in only a slight decrease in the rate of disappearance of mercapturic acid from the plasma, while bilateral nephrectomy caused a marked retardation of its clearance from the plasma. Intravenous administration of probenecid, a well known inhibitor of a renal transtubular transport system for organic acids, caused a significant retardation of mercapturate clearance from the plasma in both of the control and ureter-ligated animals. The renal accumulation of this mercapturic acid as well as its excretion into urine was inhibited by probenecid. All these data suggested that a mercapturic acid in the plasma was preferentially taken up by renal tubule cells from the basolateral side of plasma membranes via the probenecid-sensitive transtubular transport system and then excreted rapidly into the lumenal space. This transtubular transport of a mercapturic acid seems to constitute an important process in the hepato-renal cooperation in the mercapturic acid biosynthesis in vivo.
mesh_terms: D000111:Acetylcysteine / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism*; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D007684:Kidney Tubules / Q000378:metabolism*; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008297:Male; D011339:Probenecid / Q000494:pharmacology; D051381:Rats
chemical_list: D011339:Probenecid; D000111:Acetylcysteine; C029319:S-benzyl-N-acetyl-L-cysteine