Pagani R, Portolés M T, Municio A M
Mol Cell Biochem. 1984 Nov;65(1):37-44. doi: 10.1007/BF00226017.
Number and affinity constant of low affinity binding sites of insulin and glucagon to isolated hepatocytes decreased when the cells were incubated with Escherichia coli 0111:B4 lipopolysaccharide. This effect agrees with a non-specific binding of lipopolysaccharide to hepatocytes, similar to the well-recognized non-specific binding of albumin. Also, binding of different lectins to their glycoprotein receptors did not affect the [14C]lipopolysaccharide interaction with the cell membrane surface. Endotoxin depresses gluconeogenesis from lactate when the precursor was incubated with the cells for short time intervals. The longer the preincubation interval with lipopolysaccharide, the higher the inhibition of gluconeogenesis in the absence and in the presence of glucagon. The effect of endotoxin was also studied on the glucagon-induced synthesis of cyclic AMP and the glucagon binding. Levels of cyclic AMP and hormone binding decreased with increasing both endotoxin concentrations and preincubation intervals at which cells were in contact with endotoxin.
当分离的肝细胞与大肠杆菌0111:B4脂多糖一起孵育时，胰岛素和胰高血糖素低亲和力结合位点的数量和亲和常数降低。这种效应与脂多糖与肝细胞的非特异性结合一致，类似于白蛋白的公认非特异性结合。此外，不同凝集素与其糖蛋白受体的结合并不影响[14C]脂多糖与细胞膜表面的相互作用。当乳酸前体与细胞短时间孵育时，内毒素会抑制乳酸的糖异生作用。脂多糖预孵育的时间间隔越长，在无胰高血糖素和有胰高血糖素存在的情况下，糖异生的抑制作用就越高。还研究了内毒素对胰高血糖素诱导的环磷酸腺苷合成和胰高血糖素结合的影响。随着内毒素浓度的增加以及细胞与内毒素接触的预孵育时间间隔的延长，环磷酸腺苷水平和激素结合量均降低。
