Giraud-D'Hollander F, Magot T, Chevallier F
Biochimie. 1976;58(7):855-62. doi: 10.1016/s0300-9084(76)80316-1.
Rats were infused for 3.5 to 10 hrs with either red cells or plasma previously labelled in vivo by [3H]-cholesterol. Cholesterol specific radioactivities were measured in plasma, HDL, LDL and VLDL, and various tissues. Red cell infusions led to a higher labelling of free than of esterified cholesterol in the plasma of infused rats. The opposite situation was observed following plasma infusion. Comparison of free and esterified cholesterol specific radioactivities in each tissue showed that esterified cholesterol was transferred from plasma to all the tissues, except the adrenals. Study of the ratios of cholesterol specific radioactivities from one experimental group to the other in each tissue, made it possible to demonstrate clearly the occurence of hydrolysis within all the studied tissues except 5 of them where its existence remains uncertain (lung, heart, kidney, tendon, muscle) and of esterification in 3 tissues (adrenal, liver lung). In addition, ratios of cholesterol radioactivities (free/ester) were found to be identical in plasma and in 4 tissues, where neither hydrolysis nor esterification were detected (heart, muscle, kidney, tendon). This finding is an argument in favor of a simultaneous transport of free and esterified cholesterol from plasma into these 4 tissues and suggests that the entire lipoprotein particles can penetrate these tissues, with no specificity of one special class. In adrenal, unlike all other tissues: 1) the turnover of esterified cholesterol was achieved mostly by hydrolysis and esterification in situ; 2) a preferential lipoprotein class (LDL) was responsible for the transport of free cholesterol from the plasma.
给大鼠输注经[3H]-胆固醇体内标记的红细胞或血浆3.5至10小时。测量血浆、高密度脂蛋白（HDL）、低密度脂蛋白（LDL）、极低密度脂蛋白（VLDL）以及各种组织中的胆固醇比放射性。输注红细胞导致输注大鼠血浆中游离胆固醇的标记高于酯化胆固醇。输注血浆后观察到相反的情况。对每个组织中游离和酯化胆固醇比放射性的比较表明，除肾上腺外，酯化胆固醇从血浆转移到所有组织。通过研究每个组织中一个实验组与另一个实验组的胆固醇比放射性之比，可以清楚地证明，在所有研究的组织中除了5个组织（肺、心脏、肾脏、肌腱、肌肉）其水解情况尚不确定外都发生了水解，并且在3个组织（肾上腺、肝脏、肺）中发生了酯化。此外，发现血浆和4个未检测到水解或酯化的组织（心脏、肌肉、肾脏、肌腱）中的胆固醇放射性比（游离/酯化）相同。这一发现支持游离和酯化胆固醇从血浆同时转运到这4个组织中，并表明整个脂蛋白颗粒可以穿透这些组织，而不存在某一特定类别的特异性。在肾上腺中，与所有其他组织不同：1）酯化胆固醇的周转主要通过原位水解和酯化来实现；2）一种优先的脂蛋白类别（LDL）负责从血浆中转运游离胆固醇。
