The absorption and excretion of butylated hydroxyanisole in beagle dogs

Recent studies have indicated that administration of [14C]butylated hydroxyanisole (BHA) to rats, either orally or by intraperitoneal (i.p.) injection, resulted in high retention of radioactivity in the forestomach. The present study was undertaken to investigate the fate of [14C]BHA in non-rodents. 2 Groups of 5-mth-old male beagle dogs were fed a diet containing either 3% or 0.03% BHA for 7 days, and were injected i.p. with 3-tert-[methyl-14C]butyl-4-hydroxyanisole (Amersham International) at a dose of 30 muCi/kg. On the 7th day after [14C]BHA injection, all dogs were killed after fasting overnight, and the liver, kidney, heart, fat tissue and stomach were collected for radioanalysis. An additional 3 beagles served as control group. The fate of BHA after the single i.p. injection of [14C]BHA was examined by the determination of 14C-radioactivity in whole body, blood, urine, feces and several tissues. Blood, urine and feces samples were collected daily for 7 days. Blood samples were collected at intervals for 24 h. BHA was rapidly taken up in the bloodstream, and 50-80% of the total radioactivity was recovered in the urine within 2 days. 15-30% Appeared in the feces within 2 days. The tissue distribution of radioactivity 7 days after [14C]BHA injection showed only a small portion remaining in the stomach (0.16-0.19% of dose/g), liver (0.3-1.7%) and other tissues (0.02%). The radio-activity was almost evenly distributed in the three parts of the stomach (cardia, corpus and pylorus). These findings are in contrast with the previous data in rats that BHA can accumulate in high concentrations in the forestomach.