Maturation of cGMP response to ANP by isolated glomeruli.
Maturation of cGMP response to ANP by isolated glomeruli.
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分离肾小球对 ANP 的 cGMP 反应成熟。
DOI：
10.1152/ajprenal.1992.262.1.f138
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Chevalier,RL
中科院分区：
文献类型：
--
作者：
Norling,LL;Vaughan,CA;Chevalier,RL
进行实验以确定是否存在肾小球产生鸟苷3 '，5'-环一磷酸（cGMP）或cGMP从肾小球细胞中分泌的成熟增加。无论是断奶前和成年离体大鼠肾小球反应与急性上升细胞内cGMP后0.5分钟暴露于0.1 microM ANP。然而，在4小时，细胞外cGMP显着增加ANP处理的成人相比，断奶前的肾小球（P <0.005）。在缺乏3-异丁基-1-甲基黄嘌呤（IBMX）的情况下，断奶前肾小球细胞内cGMP显著升高（P <0.05）。此外，cGMP水解的磷酸二酯酶的比活性是断奶前肾小球膜的两倍（P <0.004）。最后，丙磺舒使成年肾小球cGMP输出减少60 +/-4%，而断奶前肾小球cGMP输出仅减少27 +/- 4%（P <0.05）。总之，与成人相比，ANP处理的预断奶肾小球输出较少cGMP的肾小球细胞，有较高浓度的细胞内cGMP，并有较低的cGMP特异性磷酸二酯酶活性，和有机离子转运蛋白在预断奶肾小球细胞输出cGMP的有效性较低。cGMP从离乳前肾小球中的有限转运可能是幼年大鼠ANP刺激后利钠利尿反应减弱的原因。
Experiments were done to determine whether there is a maturational increase in production of guanosine 3',5'-cyclic monophosphate (cGMP) by glomeruli or in eggression of cGMP out of glomerular cells. Both preweaned and adult isolated rat glomeruli responded with an acute rise in intracellular cGMP after 0.5-min exposure to 0.1 microM ANP. However, at 4 h extracellular cGMP was significantly greater in ANP-treated adult compared with preweaned glomeruli (P less than 0.005). In the absence of 3-isobutyl-1-methylxanthine (IBMX) intracellular cGMP was significantly higher in preweaned glomeruli (P less than 0.05). Moreover, the specific activity of phosphodiesterases for cGMP hydrolysis was twofold less in preweaned glomerular membranes (P less than 0.004). Finally, probenecid decreased export of adult glomerular cGMP by 60 +/- 4%, whereas preweaned glomerular cGMP export decreased by only 27 +/- 4% (P less than 0.05). In conclusion, compared with adult, ANP-treated preweaned glomeruli export less cGMP out of glomerular cells, have a higher concentration of intracellular cGMP, and have lower cGMP-specific phosphodiesterase activity, and the organic ion transporter in preweaned glomerular cells exports cGMP less effectively. The limited transport of cGMP out of preweaned glomeruli may account for the blunted natriuretic and diuretic response following ANP stimulation of young rats.