Expression and role of connexins in the rat renal vasculature
Expression and role of connexins in the rat renal vasculature
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DOI：
10.1038/sj.ki.5002673
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发表时间：
2008-02-01
影响因子：
19.6
通讯作者：
Suzuki, H.
中科院分区：
文献类型：
--
作者：
Takenaka, T.;Inoue, T.;Suzuki, H.
间隙连接存在于肾小球旁装置中，能够实现细胞间通讯。我们的研究通过使用特定的模拟肽确定了不同连接蛋白亚型在大鼠肾小球旁装置内的位置，以及这些亚型在肾血流动力学中的作用。免疫组织化学分析显示，连接蛋白 37 和 40 在传入小动脉的内皮细胞和肾素分泌细胞中表达，而连接蛋白 40 也在肾小球外和肾小球内系膜细胞中发现。相反，连接蛋白 43 在传入小动脉和肾小球内皮细胞中表达较弱。据报道，肾内输注肽 (GAP) 可阻断特定间隙连接（(Cx37,43)GAP27 或 (Cx40)GAP27），升高血压、血浆肾素活性和血管紧张素 II 水平，同时降低肾血浆流量，而肾小球滤过率没有显着变化。随后血压的恢复降低了肾血浆流量和肾小球滤过率。相反，(Cx43)GAP26 降低肾小球滤过率，但不改变血压、肾血浆流量、血浆肾素活性或血管紧张素 II 水平。因此，连接蛋白 37 和 40 在大鼠肾小球旁装置中表达，这些蛋白部分控制肾素-血管紧张素系统和肾脏自身调节。
Gap junctions are present in the juxtaglomerular apparatus enabling intercellular communication. Our study determined the location of different connexin subtypes within the juxtaglomerular apparatus of the rat, and the role of these subtypes in renal hemodynamics through the use of specific mimetic peptides. Immunohistochemical analysis showed connexins 37 and 40 expression in the endothelial and renin-secreting cells of the afferent arteriole, while connexin 40 was also found in extra-and intraglomerular mesangial cells. In contrast, connexin 43 was weakly expressed in endothelial cells of the afferent arteriole and within the glomerulus. Intra-renal infusion of the peptides ( GAP) reported to block specific gap junctions ((Cx37,43)GAP27 or (Cx40)GAP27), elevated blood pressure, plasma renin activity, and angiotensin II levels, while decreasing renal plasma flow without a significant change in the glomerular filtration rate. Subsequent restoration of blood pressure reduced both renal plasma flow and glomerular filtration rate. In contrast, (Cx43)GAP26 reduced glomerular filtration rate without alterations in blood pressure, renal plasma flow, plasma renin activity, or angiotensin II levels. Hence, connexins 37 and 40 are expressed in the rat juxtaglomerular apparatus and these proteins control, in part, the renin-angiotensin system and renal autoregulation.