Urinary and Fecal Coproporphyrin Excretion in Rats. III. Excretion of Injected Coproporphyrin. ∗

Abstract

Summary and Conclusions

1. Studies have been made of the urinary and fecal excretion of coproporphyrins I and III administered intravenously to rats. In the normal animal, no increase in urinary excretion occurred; approximately one-half of the injected material was excreted in the feces. 2. Coproporphyrin administered intravenously to rats was rapidly excreted in the bile via an external biliary fistula, or in the urine when complete biliary obstruction existed. Orally administered coproporphyrin did not appear to be absorbed, and approximately half was recovered from the feces. Regardless of the route of administration, only half of the coproporphyrin could be recovered. 3. In acute liver injury due to carbon tetrachloride, intravenous administration of coproporphyrin resulted in an increased urinary porphyrin excretion, with a relative reduction in the amount excreted in the feces. 4. In rats with chronic liver injury due to a choline-deficient diet virtually none of the injected porphyrin could be recovered in either urine or feces. The reason for this is unknown. 5. Rats made anemic by acute bleeding exhibited normal (i.e., increased) fecal excretion of coproporphyrin III, following its intravenous administration.