ABSORPTION AND EXCRETION OF SIMMONDSIN AFTER DIFFERENT ADMINISTRATIONROUTES IN RATS

Adult rats received simmondsin by intragastric intubation (ig) or intr aperitoneal injection (ip) or mixed in with food (MF). Food intake inh ibition was noted after administration by any of these routes, startin g within minutes after ig or MF administration and continuing for +/-2 h in the former case and for 20 h in the latter. Following ip adminis tration, food intake inhibition started after approximately 0.5 h and continued for about 2 h and was followed by a hyperphagic period. Simm ondsin was measurable in the blood, but the concentration did not corr elate with the anorexic effect. Only a fraction of the ingested or ip- administered simmondsin was excreted unmodified in the urine or feces. Ip administered simmondsin was detectable in the feces, indicating pa ssage from the blood into the gut. The presence of simmondsin in the p roximal gut seems to be necessary for the induction of anorexia.