Studies on Absorption, Distribution, Excretion and Metabolism of ^3H-1α-Hydroxycholecalcifelol in the Monkey (Macaca Mulatta)

Abstract

The absorption, distribution, excretion and metabolism of 2-^3H-1α-OH-D_3 (4.2Ci/mmol, 4.3μg/40.3μCi/head) in rhesus monkey were studied after administered in gastrointestine pernasally. 1) Peak blood levels (0.004% of administered radioactivity/ml, respectively) were observed at both 9 and 18〜24 hours with apparent half life of 24 hours. 2) There was no specific distribution of radioactivity in the tissues studied. 3) Until 48 hours, 2.5 and 45% of the administered radioactivity were recovered in the urine and feces respectively. 4) Both ^3H-1α-OH-D_3 and ^3H-1α, 25-(OH)_2-D_3 were detected in all the tissues examined. The latter was predominant than the former in the blood and liver. 5) In the bile collected at 9 hours, ^3H-1α-OH-D_3 and ^3H-1α, 25-(OH)_2-D_3 were detected in a few percent of the total radioactivity recovered. 6) The above results were compared with these of rats obtained in the earlier study.