Study of ¹³¹I-triolein tolerance curves in different species of animals

Abstract

Striking species differences were observed following the administration of ¹³¹I-triolein to humans, monkeys, rabbits and chicks. Humans exhibited significantly higher levels of total and fat-bound radio-activity in blood than the rest of the species. Rats at the other extreme exhibited lowest levels of total and fat-bound blood radioactivity and earliest fat-bound peak activity. The levels of fat-bound radioactivity in the blood of chicks, rabbits and monkeys were low and the curves were flat. The ratio of total/fat-bound radioactivity was higher in human subjects than in other species. Twenty-four hour urinary ex-cretion of radioactivity was also higher in humans than in monkeys and rabbits. Tolerance curves obtained with chromatographically purified ¹³¹I-triolein were not significantly different from those obtained with impure ¹³¹I-triolein in humans, monkeys, rabbits and chicks.