Garcia R, Viloria M D, Municio A M
J Steroid Biochem. 1985 Mar;22(3):377-85. doi: 10.1016/0022-4731(85)90441-8.
The effect of endotoxin (lipopolysaccharide from E. coli) on isolated adrenocortical cells was examined. Lipopolysaccharide decreased the ACTH-induced steroidogenesis. This effect was shown by all corticotropin concentrations studied, and the longer the incubation time, the higher the effect produced. The rate of decrease of ACTH-induced steroidogenesis was dependent on the concentration of lipopolysaccharide in the medium. Binding of [125I]ACTH to adrenocortical cells was modified by lipopolysaccharide; this modification was related to a decrease of the ACTH-induced steroidogenesis. This effect supports the hypothesis of a direct interaction between lipopolysaccharide and the cell membrane with a concomitant distortion of the cell surface affecting the ACTH receptor sites of their environment. [14C]Lipopolysaccharide binds to isolated adrenocortical cells. Binding specificity was investigated by competitive experiments in the presence of various types of endotoxins, polypeptide hormones and proteins. Unlabelled lipopolysaccharide from the same bacterial strain and isolated under identical conditions than the labelled lipopolysaccharide exerted the strongest inhibitory activity. Unlabelled lipopolysaccharide of various strains different from that originating the labelled lipopolysaccharide exerted the less displacement. It would imply a certain kind of specificity but the decrease in the binding of lipopolysaccharide produced by ACTH and glucagon suggests the existence of non-specific interactions between lipopolysaccharide and cell membrane.
研究了内毒素（大肠杆菌来源的脂多糖）对分离的肾上腺皮质细胞的作用。脂多糖降低了促肾上腺皮质激素（ACTH）诱导的类固醇生成。在所研究的所有促肾上腺皮质激素浓度下均显示出这种作用，且孵育时间越长，产生的作用越高。ACTH诱导的类固醇生成的降低速率取决于培养基中脂多糖的浓度。脂多糖改变了[125I]ACTH与肾上腺皮质细胞的结合；这种改变与ACTH诱导的类固醇生成的降低有关。这一作用支持了脂多糖与细胞膜直接相互作用的假说，同时细胞表面的扭曲影响了其周围环境中的ACTH受体位点。[14C]脂多糖与分离的肾上腺皮质细胞结合。通过在各种类型的内毒素、多肽激素和蛋白质存在下进行竞争实验来研究结合特异性。来自与标记脂多糖相同细菌菌株且在相同条件下分离的未标记脂多糖具有最强的抑制活性。与产生标记脂多糖的菌株不同的各种菌株的未标记脂多糖产生的置换作用较小。这意味着存在某种特异性，但ACTH和胰高血糖素导致的脂多糖结合减少表明脂多糖与细胞膜之间存在非特异性相互作用。
