Lofland H B, Clarkson T B, St Clair R W, Lehner N D
J Lipid Res. 1972 Jan;13(1):39-47.
Certain individual squirrel monkeys ("hypo-responders") are able to remain normocholesterolemic when fed diets containing cholesterol (0.5 mg/kcal). Other squirrel monkeys ("hyperresponders") when fed the same diet become hypercholesterolemic. The purpose of these studies was to identify the mechanisms which allow hyporesponders to compensate for dietary cholesterol. Using formula diets and sterol balance techniques, we have compared cholesterol absorption, synthesis, excretion, and turnover in hypo- and hyperresponding monkeys. Cholesterol absorption was essentially identical in the two groups (about 55 mg/day). Cholesterol synthesis was likewise similar in the two groups (about 35 mg/day) and there was no evidence of feedback inhibition at the level of cholesterol fed. Hyporesponders had faster turnover rates and smaller body cholesterol pools than did hyperresponders. Excretion of neutral steroids was similar for hypo- and hyperresponders and did not change with cholesterol feeding. In contrast, hyporesponders increased bile acid excretion shortly after cholesterol feeding was begun. Hyperresponders responded more slowly and to a lesser degree. It is concluded that, in this species, the mechanism of control of plasma cholesterol levels is related to the rate of conversion of cholesterol to bile acids.
某些个体松鼠猴（“低反应者”）在喂食含胆固醇（0.5毫克/千卡）的日粮时能够保持正常胆固醇水平。其他松鼠猴（“高反应者”）在喂食相同日粮时则会出现高胆固醇血症。这些研究的目的是确定使低反应者能够代偿膳食胆固醇的机制。使用配方日粮和甾醇平衡技术，我们比较了低反应和高反应猴子的胆固醇吸收、合成、排泄及周转情况。两组的胆固醇吸收基本相同（约55毫克/天）。两组的胆固醇合成同样相似（约35毫克/天），且没有证据表明在喂食胆固醇水平上存在反馈抑制。与高反应者相比，低反应者的周转速度更快，体内胆固醇池更小。低反应者和高反应者的中性类固醇排泄相似，且不会因喂食胆固醇而改变。相反，低反应者在开始喂食胆固醇后不久胆汁酸排泄增加。高反应者反应较慢且程度较小。得出的结论是，在这个物种中，血浆胆固醇水平的控制机制与胆固醇转化为胆汁酸的速率有关。
