TY - JOUR T1 - THE RENAL TUBULAR TRANSPORT AND METABOLISM OF SEROTONIN (5-HT) AND 5-HYDROXYINDOLEACETIC ACID (5-HIAA) IN THE CHICKEN JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 749 LP - 762 VL - 175 IS - 3 AU - RAMSES HAKIM AU - WILLIAM M. WATROUS AU - JAMES M. FUJIMOTO Y1 - 1970/12/01 UR - http://jpet.aspetjournals.org/content/175/3/749.abstract N2 - By use of the Sperber technique, C14-serotonin (5-HT) was shown to be actively transported. The transport was characterized by a large apparent tubular excretion fraction represented by an excess of 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) (a metabolite) in the urine from the kidney on the side of the i.v. infusion as contrasted to the contralateral side. Serotonin transport was inhibited by mepiperphenidol and quinine, which are blockers of the organic cation transport system. Probenecid partially inhibited 5-HT excretion without affecting either metabolism of 5-HT or excretion of intracellularly formed 5-HIAA. Intracellular metabolism in the kidney of 5-HT to 5-HIAA was blocked by the monoamine oxidase inhibitor, pheniprazine, with no effect on 5-UT transport. When infused i.v. 5-HIAA was actively secreted by the organic anion transport system evidenced by complete block of transport by probenecid. Probenecid did not affect the excretion of H3-5-HIAA formed intracellularly in the kidney from H3-5-HT while at the time the transport of C14-5-HIAA infused simultaneously with the H3-5-HT was effectively blocked. Thus, these findings led to the localization of the site of active transport of 5-HIAA and the site for the blocking action of probenecid to the peritubular border of the cell. © 1970 by The Williams & Wilkins Co. ER -