EFFECTS OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD) ON THE VITAMIN A STATUS OF HARTLEY GUINEA-PIGS, SPRAGUE-DAWLEY RATS, C57B1 6 MICE, DBA 2 MICE, AND GOLDEN SYRIAN-HAMSTERS

Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on hepatic, renal, lung, and serum vitamin A levels were investigated in species/strains, which show highly variable susceptibility to TCDD toxicity. Young male Hartley guinea pigs, Sprague-Dawley rats, C57B1/6 mice, DBA/2 mice, and Golden Syrian hamsters received single intraperitoneal doses, in the range 0.5-400-mu-g TCDD/kg body weight, aimed to produce a similar toxic and limited lethal effect in all species. Animals were sacrificed 1, 7, 14, 28, 56, and 112 days after TCDD injection. The time-related increase in hepatic vitamin A storage was inhibited by TCDD in all species studied, but the doses required to produce the inhibition were considerably varied due to species. The duration of the inhibition was dependent both on dose and species. All species, except for the guinea pig, managed to increase the liver reserves of vitamin A at the end of the study, as compared to the amount present at the time of TCDD treatment. A marked increase in renal vitamin A content, related to TCDD exposure, was observed in the rats, as opposed to a slight decrease in the guinea pigs and no effect in mice or hamsters. All species tested, except for the C57B1/6 mouse, showed a marked TCDD-related decrease in pulmonary vitamin A. The rat was the only species which showed a consistent effect (a small increase) in serum vitamin A levels, as a result of exposure to TCDD. The effects of TCDD on the hepatic and pulmonary vitamin A contents correlated reasonably well with the observed toxic response in this study. However, the correlation could not be observed for the effects of TCDD on renal, and serum vitamin A levels.