Absorption of 14C-clanobutin-Na isolated perfused intestinal segments in vitro of rats
Strugala, G.; Overhoff, H.; Forth, W.
Arzneimittel-Forschung 31(3): 429-433
1. The absorption of 14C-labelled 4-[4-chloro-N-(4-methoxyphenyl)-benzamido]-butyric acid (clanobutin) was investigated on isolated perfused jejunal segments of rats in vitro according to the method of Fisher and Parsons and using everted (Wilson and Wiseman) and non-everted sac preparations. 2. Transfer to and content of the mucosal tissue of 14C-clanobutin in isolated perfused jejunal segments is proportional to the concentration administered on the mucosal side in the range of 1-100 mumol/l. 3. The concentration of 14C-clanobutin in the absorbate is 1.5 times higher than in the perfusion fluid. As compared on the basis nmol/ml perfusion fluid versus nmol/g wet weight the concentration of 14C-clanobutin in the tissue is twice that in the perfusion fluid. 4. No detectable metabolic alteration of 14C-clanobutin could be demonstrated during the passage across the jejunal epithelium. 5. The transfer of 14C-clanobutin in everted sac preparations from the mucosal to the serosal side (M leads to S) is about 3.7 times higher than in the reverse direction (S leads to M). 6. In the intestinal tissue the concentration of 14C-clanobutin is 1.7 times higher than that in the incubation medium; this calculation was made on the basis nmol/ml fluid versus nmol/g tissue wet weight. 7. When having administered 14C-clanobutin on both sides, on the serosal side the 14C-clanobutin concentration increases slightly whereas on the mucosal side due to uptake into the intestinal a slight decrease of the 14C-clanobutin concentration was observed.