Comparative effects of prednisolone and thyroid hormone on bile secretion in the dog

¹ Departments of Physiology and Pathology, New York State Veterinary College, Cornell University, Ithaca, New York

The enterohepatic circulation of euthyroid dogs contained 1.25 ± 0.24 g bile acids/10 kg body wt. The bile acid content of the enterohepatic circulation of hyperthyroid dogs given thyroid hormones for 3 weeks was 0.72 ± 0.21g/10kg body wt., a significant difference from the control group (P(t) < .01). No significant differences in biliary cholesterol output were recorded. Bile secretory changes in the hyperthyroid state were unrelated to food intake or changes in body weight. No evidence was found to indicate an early period of enhanced bile acid or biliary cholesterol secretion accompanying thyroid hormone administration. The administration of prednisolone trimethylacetate to euthyroid dogs resulted in a significant (P(t) < .01) increase in total bile volume recovered. The enterohepatic bile acid content of the prednisolone-treated dog was 1.84 ± .48 g/10 kg body wt., the difference from the control group being of marginal significance (P(t) < .05 > .02). Two hepatic function tests, the secretory response to sodium dehydrocholate administration and the rate of disappearance of bromsulfonphthalein from plasma, did not indicate any gross derangement in hepatic function in the hyperthyroid or prednisolone-treated dogs.