Absorption, distribution and excretion of (carboxy-14C)bisbromoacetyl hexestrol

Bisbromoacetyl hexestrol is a new antitumor agent. Mice were given intragastrically [carboxy-14C]bisbromoacetyl hexestrol 500 mg/kg, the radioactivity in blood detected on a moderate level up to 24 h. In rats treated ig with 250 mg/kg, the radioacticity in blood attained the peak at 6-8 h. The tissue distribution of 14C in mice bearing sarcoma 180 was high in liver and stomach, moderate in intestine, kidney, prostate, epididymis, tumor and spleen. A marked retention of 14C was found in both uterus and ovary. Following ig gavage of [carboxy-14C] bisbromoacetyl hexestrol in 48 h, recoveries of 14C in mice were 36% in urine and 37% in feces. Choledochostomized rats excreted about 40% of the 14C within 12 h. Thin layer chromatograohy revealed that the polarity of the metabolite was higher.