ABSORPTION AND METABOLISM OF PROSTAGLANDIN E1 BY PERFUSED RAT JEJUNUM IN VITRO

Segments of rat jejunum were perfused in vitro with Krebs-Ringer bicarbonate buffer containing [1-14C]prostaglandin E1 or [5,6-3H2]prostaglandin E1. 1. 1. When segments were perfused with [1-14C]prostaglandin E1, approx. 15% of the radioactivity disappearing from the mucosal fluid in 60 min was translocated to the serosal fluid, 34% was taken up by the perfused tissue and 49% was lost from the system, presumably as 14CO2. 2. 2. 14C Activity was distributed throughout tissue lipids: 17% was in the total nonsaponifiable fraction, 6% in the digitonin precipitable sterols, 47% in ethyl ether extracts of the saponifiable fraction and 36% in the ether extracted aqueous phase. 3. 3. When segments were perfused with [5,6-3H2]prostaglandin E1, only about 0.1% of the total radioactivity translocated to the serosal fluid was identified as intact prostaglandin E1 by reverse isotope dilution. 4. 4. [5,6-3H2] Prostaglandin E1 was not incorporated into intestinal tissue glycerol or cholesterol esters under conditions where [9,10-3H2]palmitic acid was esterified. These data support the hypothesis that the intestine may be a primary site of oxidative metabolism of orally administered prostaglandin E1. © 1969.