Sterol synthesis in vivo in 18 tissues of the squirrel monkey, guinea pig, rabbit, hamster, and rat.
Sterol synthesis in vivo in 18 tissues of the squirrel monkey, guinea pig, rabbit, hamster, and rat.
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DOI：
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发表时间：
1983-03
影响因子：
6.5
通讯作者：
D. Spady;J. Dietschy
中科院分区：
文献类型：
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作者：
D. Spady;J. Dietschy
本研究旨在测量和比较五种不同动物体内主要器官中洋地黄皂苷可沉淀甾醇（DPS）的合成速率。通过测量[3 H]水掺入完整动物DPS中的速度来评估这些速率。选择使用的动物包括主要以高密度脂蛋白（大鼠、仓鼠）或低密度脂蛋白（豚鼠）（分别为HDL和LDL）携带大部分血浆胆固醇或更均匀分布在LDL和HDL组分之间（猴和兔）的种属。当标准化为100 g的恒定体重时，大鼠（16.1 mumol/hr）的整个动物甾醇合成远高于其他四个物种（2.9-4.6 mumol/hr）。这一独特的高甾醇合成率主要归因于大鼠肝脏将[3 H]水掺入DPS的极高速率。当以每克组织表示时，在所有物种中发现肾上腺、卵巢和胃肠道等组织中新合成的甾醇含量最高。然而，[3 H]DPS在肝脏中的含量变化明显，从大鼠的2279 nmol/hr/g到豚鼠的109 nmol/hr/g。因此，当表示为全身合成的百分比时，大鼠的整个肝脏含有51%的[3 H]DPS，而猴（40%）、仓鼠（27%）、兔（18%）和豚鼠（16%）中的该数字要低得多。因此，在除大鼠外的所有物种中，甾醇合成的主要部位似乎是胃肠道、尸体（主要是肌肉）和皮肤。此外，尽管每克肾上腺中新合成的甾醇含量高于所有检查物种中几乎任何其他组织中的含量，但进一步证明，在大鼠中，大多数[3 H]DPS来自血液（因此，最终来自肝脏），而在其他物种中，它主要是在腺体内局部合成的。因此，这些研究表明，在许多物种中，肝脏作为甾醇合成的位点在数量上远不如以前认为的重要，并且作为这一点的相关性，肝外组织利用的大多数甾醇主要是在这些组织内局部合成的。
This study was undertaken to measure and compare the rates at which digitonin-precipitable sterols (DPS) were synthesized in vivo in the major organs of five different animal species. These rates were assessed by measuring the velocity at which [3H]water was incorporated into DPS in the intact animal. The animals used were chosen to include species that carried most of their plasma cholesterol either predominantly in high (rat, hamster) or low (guinea pig) density lipoproteins (HDL and LDL, respectively) or more evenly distributed between the LDL and HDL fractions (monkey and rabbit). Whole animal sterol synthesis was much higher in the rat (16.1 mumol/hr) than in the other four species (2.9-4.6 mumol/hr) when normalized to a constant body weight of 100 g. This uniquely high rate of sterol synthesis could be attributed predominantly to an extremely high rate of incorporation of [3H]water into DPS by the liver of the rat. When expressed per g of tissue, the highest content of newly synthesized sterol in all species was found in tissues such as adrenal gland, ovary, and gastrointestinal tract. However, the content of [3H]DPS in the liver varied markedly from a high of 2279 nmol/hr per g in the rat to a low of only 109 nmol/hr per g in the guinea pig. Consequently, when expressed as a percentage of total body synthesis, the whole liver of the rat contained 51% of the [3H]DPS while this figure was much lower in the monkey (40%), hamster (27%), rabbit (18%), and guinea pig (16%). Thus, in all species except the rat, the major sites for sterol synthesis appeared to be the gastrointestinal tract, carcass (predominantly the muscle), and skin. In addition, even though the content of newly synthesized sterol per g of adrenal gland was higher than in nearly any other tissue in all of the species examined, it was further demonstrated that in the rat most of this [3H]DPS was derived from the blood (and, therefore, ultimately from the liver) whereas in the other species it was largely synthesized locally within the gland. Thus, these studies demonstrated that in many species the liver is quantitatively far less important as a site for sterol synthesis than previously believed and, as a correlate of this, most sterol utilized by extrahepatic tissues is largely synthesized locally within those tissues.