High Ca2+ inhibits peptide hormone-dependent cAMP production specifically in thick ascending limbs of Henle.
High Ca2+ inhibits peptide hormone-dependent cAMP production specifically in thick ascending limbs of Henle.
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高 Ca2 抑制肽激素依赖性 cAMP 产生，特别是在粗厚的 Henle 上升肢中。
DOI：
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发表时间：
1986
期刊：
影响因子：
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通讯作者：
K. Kurokawa
中科院分区：
文献类型：
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作者：
K. Takaichi;K. Kurokawa
我们以前表明，增加Ca 2+浓度的孵育介质中抑制cAMP的生产响应于加压素（AVP），胰高血糖素或毛喉素在髓厚的上升肢的汉勒（MTAL），但不是在小鼠肾脏的髓集合管。在本研究中，我们研究，从小鼠肾脏解剖的肾单位片段，是否高钙的抑制作用是特定的MTAL。培养液中Ca ~（2+）浓度从1增加到5 mM，可抑制甲状旁腺素（PTH）、降钙素、AVP或胰高血糖素刺激的Henle氏皮质粗升支（CTAL）cAMP的产生，但不抑制PTH或降钙素刺激的近曲小管cAMP的产生和AVP刺激的皮质集合小管cAMP的产生。在CTAL中，高环境Ca 2+也抑制毛喉素刺激的cAMP产生。因此，我们目前的数据表明，高钙抑制cAMP的生产，特别是在厚的汉勒升支，但不是在其他肾单位段。高浓度的Ca ~（2+）可在受体后位点抑制腺苷酸环化酶，其中一个位点可能是TAL中腺苷酸环化酶的催化单位。
We showed previously that increasing Ca2+ concentration in the incubation medium suppressed cAMP production in response to vasopressin (AVP), glucagon or forskolin in the medullary thick ascending limb of Henle (MTAL) but not in medullary collecting tubules of mouse kidney. In the present study, we examined, using nephron segments dissected from mouse kidney, whether the inhibitory effect of high Ca2+ is specific to MTAL. Increasing Ca2+ in the incubation medium from 1 to 5 mM inhibited cAMP production in response to parathyroid hormone (PTH), calcitonin, AVP or glucagon in cortical thick ascending limbs of Henle (CTAL), but dit not inhibit cAMP production stimulated by PTH or calcitonin in proximal convoluted tubules and that by AVP in cortical collecting tubules. In CTAL, high ambient Ca2+ also inhibited cAMP production stimulated by forskolin. Thus, our present data show that high Ca2+ inhibits cAMP production specifically in thick ascending limbs of Henle but not in the other nephron segments. High ambients Ca2+ may inhibit adenylate cyclase at postreceptor site(s) one of which may be the catalytic unit of the enzyme in TAL.