Hruska K A, Moskowitz D, Esbrit P, Civitelli R, Westbrook S, Huskey M
J Clin Invest. 1987 Jan;79(1):230-9. doi: 10.1172/JCI112788.
Parathyroid hormone (PTH) produced a dose-dependent immediate stimulation of inositol triphosphate and diacylglycerol production in the opossum kidney cell line, primary culture proximal tubular cells, and basolateral membranes from canine proximal tubular segments. The increase in inositol triphosphate production was accompanied by a minor increase in inositol phosphate and no significant increase in inositol bisphosphate production. Associated with the changes in inositol triphosphate and diacylglycerol, there was an immediate hydrolysis of phosphatidylinositol 4'5-bisphosphate. The effect on phospholipid hydrolysis was followed by stimulation of phosphorylation of phosphatidylinositol 4' monophosphate and phosphatidylinositol. PTH produced a sudden increase in cytoplasmic Ca2+ in opossum kidney cells that persisted for approximately 1 min. Inositol triphosphate transiently increased cytoplasmic Ca2+ in saponin-treated opossum kidney and primary culture proximal tubule cells. The effects of PTH were not mimicked by cyclic nucleotides. In fact, cyclic AMP appeared to diminish inositol triphosphate production. These results demonstrate that PTH may activate renal tubular epithelial cells by the production of inositol triphosphate and diacylglycerol.
甲状旁腺激素（PTH）对负鼠肾细胞系、原代培养的近端肾小管细胞以及犬近端肾小管节段的基底外侧膜产生了剂量依赖性的肌醇三磷酸和二酰基甘油生成的即时刺激作用。肌醇三磷酸生成的增加伴随着肌醇磷酸的轻微增加以及肌醇二磷酸生成无显著增加。与肌醇三磷酸和二酰基甘油的变化相关，磷脂酰肌醇4'5-二磷酸立即发生水解。对磷脂水解的影响之后是磷脂酰肌醇4'单磷酸和磷脂酰肌醇磷酸化的刺激。PTH使负鼠肾细胞中的细胞质Ca2+突然增加，并持续约1分钟。肌醇三磷酸使皂素处理的负鼠肾细胞和原代培养的近端小管细胞中的细胞质Ca2+短暂增加。环核苷酸不能模拟PTH的作用。事实上，环磷酸腺苷似乎会减少肌醇三磷酸的生成。这些结果表明，PTH可能通过生成肌醇三磷酸和二酰基甘油来激活肾小管上皮细胞。
