METABOLISM OF CL-36-ORNIDAZOLE AFTER ORAL APPLICATION TO THE MALE-RATIN RELATION TO ITS ANTIFERTILITY ACTIVITY

1. The antimycotic ornidazole (a male antifertility agent in rats) was synthesized incorporating Cl-36 in the chloropropyl sidechain and its metabolism was investigated in the male rat after oral ingestion. 2. Blood levels of radioactivity were low over the first 24 h and there w as no tissue accumulation of radioactivity over 48 h. 3. Most of the e xcreted radioactivity (20 % of the ingested dose) appeared in the urin e within the first 24 h. 4. Three major compounds were detected in 0-2 4-h urine samples and were characterized as ornidazole (13 % of total radioactivity), Cl- (22 %) and 3-chlorolactate (30 %), the oxidation p roduct of 3-chlorolactaldehyde. 5. No polyuria or glucosuria was obser ved following the oral administration of ornidazole, suggesting that a ny (R)-3-chlorolactate produced was insufficient to affect renal metab olism. 6. Conversion of ornidazole initially to (R, S)-alpha-chlorohyd rin or ultimately to the glycolytic inhibitor (S)-3-chlorolactaldehyde could explain its antifertility action in the male rat.