Inscho E W
Department of Physiology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
Am J Physiol Renal Physiol. 2001 Jun;280(6):F927-44. doi: 10.1152/ajprenal.2001.280.6.F927.
In the last 10-15 years, interest in the physiological role of P2 receptors has grown rapidly. Cellular, tissue, and organ responses to P2 receptor activation have been described in numerous in vivo and in vitro models. The purpose of this review is to provide an update of the recent advances made in determining the involvement of P2 receptors in the control of renal hemodynamics and the renal microcirculation. Special attention will be paid to work published in the last 5-6 years directed at understanding the role of P2 receptors in the physiological control of renal microvascular function. Several investigators have begun to evaluate the effects of P2 receptor activation on renal microvascular function across several species. In vivo and in vitro evidence consistently supports the hypothesis that P2 receptor activation by locally released extracellular nucleotides influences microvascular function. Extracellular nucleotides selectively influence preglomerular resistance without having an effect on postglomerular tone. P2 receptor inactivation blocks autoregulatory behavior whereas responsiveness to other vasoconstrictor agonists is retained. P2 receptor stimulation activates multiple intracellular signal transduction pathways in preglomerular smooth muscle cells and mesangial cells. Renal microvascular cells and mesangial cells express multiple subtypes of P2 receptors; however, the specific role each plays in regulating vascular and mesangial cell function remains unclear. Accordingly, the results of studies performed to date provide strong support for the hypothesis that P2 receptors are important contributors to the physiological regulation of renal microvascular and/or glomerular function.
在过去10至15年中，人们对P2受体的生理作用的兴趣迅速增长。在众多体内和体外模型中已经描述了细胞、组织和器官对P2受体激活的反应。本综述的目的是提供关于确定P2受体在肾血流动力学和肾微循环控制中的作用方面的最新进展。将特别关注过去5至6年发表的旨在了解P2受体在肾微血管功能生理控制中的作用的研究。几位研究人员已经开始评估P2受体激活对多个物种肾微血管功能的影响。体内和体外证据一致支持这样的假设，即局部释放的细胞外核苷酸激活P2受体影响微血管功能。细胞外核苷酸选择性地影响入球小动脉前阻力，而对出球小动脉张力没有影响。P2受体失活会阻断自身调节行为，而对其他血管收缩剂激动剂的反应性则得以保留。P2受体刺激可激活入球小动脉平滑肌细胞和系膜细胞中的多种细胞内信号转导途径。肾微血管细胞和系膜细胞表达多种P2受体亚型；然而，每种亚型在调节血管和系膜细胞功能中所起的具体作用仍不清楚。因此，迄今为止进行的研究结果为P2受体是肾微血管和/或肾小球功能生理调节的重要贡献者这一假设提供了有力支持。
