Abstract
2.5mg of retinoic acid-6,7^<14>C_2 were infused into the midportions of ligated intestines of rats and estimation of both radioactivity and retinoic acid in organs and tissues of the animals was undertaken at 1 and 6 hours after the infusion. Both radioactivity and retinoic acid were detected in liver, kidney, bone, muscle and skin after 1 hour, but after 6 hours, only trace of or no radioactivity was detected in them, except liver. Radioactivity in the upper portions of the intestines and the urine after 6 hours was 32 and 18% of the total given activity. Excretion of metabolites of retinoic acid was shown to have two ways to urine through kidney and to upper intestine through gall-bladder. If one way was shut down by ligation, the excretion of activity was shown to be exclusive to the urine or to the upper intestine. Radioautography of the urine and the upper intestine content demonstrated 4 metabolites (Rf 0.05,0.3,0.55,0.95) in the urine and 4 metabolites (Rf 0.05,0.15,0.75,1.0) in the upper intestine. Retinoic acid and its ester was recovered from the upper intestine but no tetinoic acid was found in the urine.
