Thyroid hormones L-Thyroxine,

This specifity for cholate or its conjugates on cholesterol absorption has also been demonstrated by modification of biliary bile acid composition by hormonal perturbations (see[40]). For example, in hypothyroid rats, there is a diminished biliary output of bile acids[41], and a shift in the ratio of biliary cholate and cheno-deoxycholate. This ratio is approximately 3 1 cholate to cheno-deoxycholate in normal rats and is shifted dramatically (9 1) in hypothyroid rats[42]. As might be expected, this hormonal deficiency results in multiple alterations in overall physiology, among which are hypercholesterolemia and increased absorbability of choles-terol[40]. Conversely, administration of thyroid hormones (L-thyroxine or triiodothyronine) results in diminished levels of biliary cholate, and proportional increases in chenodeoxycholate. 

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