Growth hormone activates phospholipase C in proximal tubular basolateral membranes from canine kidney.
Growth hormone activates phospholipase C in proximal tubular basolateral membranes from canine kidney.
复制标题
生长激素激活犬肾近端管状基底外侧膜中的磷脂酶 C。
DOI：
10.1073/pnas.86.16.6363
复制
发表时间：
1989
影响因子：
11.1
通讯作者：
Hammerman,MR
中科院分区：
文献类型：
--
作者：
Rogers,SA;Hammerman,MR
为了描述生长激素（GH）在近端小管中的“信号”转导途径，我们将从犬肾分离的基底外侧膜与人生长激素（hGH）或人催乳素（hPrl）孵育，并测量三磷酸肌醇（InsP 3）悬浮液和膜中可提取的甘油二酯的水平。与hGH孵育，但不是hPrl，InsP 3和二酰甘油的水平增加浓度依赖性的方式。半数最大效应发生在0.1和1 nM hGH之间。与1 nM hGH孵育5秒后，InsP 3水平升高，15秒后增加最大。由于InsP 3在膜悬浮液中的去磷酸化，60秒后不再检测到增加。hGH不影响去磷酸化速率。在悬浮于0、0.1和0.2 mM钙中的膜中可检测到hGH刺激的InsP 3增加，但在0.3或1.0 μ M钙中不可检测到。125 I-标记的hGH-受体复合物的Mr值为66，000和140，000，在分离的基底外侧膜。我们的研究结果表明，GH激活磷脂酶C（磷脂酰胆碱胆碱磷酸水解酶，EC 3.1.4.3）在离体犬肾近端肾小管基底外侧膜，可能后结合到一个特定的受体。这一过程可以介导GH通过近端肾小管细胞质膜和其他地方的“信号”传递。
To delineate pathways for "signal" transduction by growth hormone (GH) in proximal tubule, we incubated basolateral membranes isolated from canine kidney with human growth hormone (hGH) or human prolactin (hPrl) and measured levels of inositol trisphosphate (InsP3) in suspensions and of diacylglycerol extractable from the membranes. Incubation with hGH, but not hPrl, increased levels of InsP3 and diacylglycerol in a concentration-dependent manner. Half-maximal effects occurred between 0.1 and 1 nM hGH. Increased levels of InsP3 were measured after as little as 5 sec of incubation with 1 nM hGH, and increase was maximal after 15 sec. Increases were no longer detectable after 60 sec because of dephosphorylation of InsP3 in membrane suspensions. hGH did not affect rates of dephosphorylation. hGH-stimulated increases in InsP3 were detectable in membranes suspended in 0, 0.1, and 0.2 mM calcium but not in 0.3 or 1.0 microMs calcium. 125I-labeled hGH-receptor complexes with Mr values of 66,000 and 140,000 were identified in isolated basolateral membranes. Our findings establish that GH activates phospholipase C (phosphatidylcholine cholinephosphohydrolase, EC 3.1.4.3) in isolated canine renal proximal tubular basolateral membranes, potentially after binding to a specific receptor. This process could mediate "signal" transmission by GH across the plasma membrane of the proximal tubular cell and elsewhere.