Low density lipoprotein receptors in bovine adrenal cortex. II. Low density lipoprotein binding to membranes prepared from fresh tissue.
Low density lipoprotein receptors in bovine adrenal cortex. II. Low density lipoprotein binding to membranes prepared from fresh tissue.
复制标题
牛肾上腺皮质中的低密度脂蛋白受体。
作者：
Petri T. Kovanen;Sandip K. Basu;Joseph L. Goldstein;Michael S. Brown
低密度脂蛋白（LDL）结合活性测定在整个匀浆和膜制备新鲜牛肾上腺皮质通过超离心法。125 I-标记的LDL在隔离膜的结合位点共享的LDL受体先前在培养的牛肾上腺皮质细胞的完整单层证明的属性。肾上腺皮质中高亲和力[125 I]碘-LDL结合活性的量是相同腺体髓质中的6- 12倍。大量的高亲和力[125 I]碘-LDL结合活性也存在于卵巢黄体中，但不在卵巢黄体中。在其他14种牛组织中观察到少量的高亲和力结合活性。这些结果支持了牛肾上腺皮质中的细胞可以通过受体介导的血浆LDL摄取来获得胆固醇用于类固醇激素合成的概念。
Low density lipoprotein (LDL)-binding activity was measured in whole homogenates and membranes prepared from fresh bovine adrenal cortex by an ultracentrifugation assay. The binding site for 125I-labeled LDL in isolated membranes shared the properties of the LDL receptor previously demonstrated in intact monolayers of cultured bovine adrenocortical cells. The amount of high affinity [125I]iodo-LDL-binding activity in the adrenal cortex was 6- to 12-fold higher than in the medulla of the same glands. Large amounts of high affinity [125I]iodo-LDL-binding activity were also present in the ovarian corpus luteum but not in the ovarian interstitium. Lesser amounts of high affinity binding activity were observed in 14 other bovine tissues. These results lend support to the concept that cells in the bovine adrenal cortex can obtain cholesterol for steroid hormone synthesis through the receptor-mediated uptake of plasma LDL.