[Caffeine and bile secretion. Experimental studies in the unanaesthetized piglet (author's transl)]

We investigated the distribution and excretion of 8-14C-caffeine as well as the effects of caffeine on bile secretion in the unanaesthetized piglet after intravenous and intraduodenal application. The findings confirm a) data known from other species concerning the intestinal absorption, distribution and excretion of 8-14C-caffeine, b) the delayed plasma disappearance of 8-14C-caffeine known in the pig following an initial rapid disappearance rate and c) a hydrocholeresis, so far only known from rats. However, the increase in bile flow accompanied by an increase of urine flow was noticed not before 3--4 h after caffeine application. Therefore the question arises whether this increase is caused by caffeine itself or by its metabolites. On the basis of our results and those of the literature it is attempted to answer this question.