Navar L G, Inscho E W, Majid S A, Imig J D, Harrison-Bernard L M, Mitchell K D
Department of Physiology, Tulane University Medical Center, New Orleans, Louisiana, USA.
Physiol Rev. 1996 Apr;76(2):425-536. doi: 10.1152/physrev.1996.76.2.425.
There has been an explosive growth of interest in the multiple interacting paracrine systems that influence renal microvascular function. This review first discusses the membrane activation mechanisms for renal vascular control. Evidence is provided that there are differential activating mechanisms regulating pre- and postglomerular arteriolar vascular smooth muscle cells. The next section deals with the critical role of the endothelium in the control of renal vascular function and covers the recent findings related to the role of nitric oxide and other endothelial-derived factors. This section is followed by an analysis of the roles of vasoactive paracrine systems that have their origin from adjoining tubular structures. The interplay of signals between the epithelial cells and the vascular network to provide feedback regulation of renal hemodynamics is developed. Because of their well-recognized contributions to the regulation of renal microvascular function, three major paracrine systems are discussed in separate sections. Recent findings related to the role of intrarenally formed angiotensin II and the prominence of the AT1 receptors are described. The possible contribution of purinergic compounds is then discussed. Recognition of the emerging role of extracellular ATP operating via P2 receptors as well as the more recognized functions of the P1 receptors provides fertile ground for further studies. In the next section, the family of vasoactive arachidonic acid metabolites is described. Possibilities for a myriad of interacting functions operating both directly on vascular smooth muscle cells and indirectly via influences on endothelial and epithelial cells are discussed. Particular attention is given to the more recent developments related to hemodynamic actions of the cytochrome P-450 metabolites. The final section discusses unique mechanisms that may be responsible for differential regulation of medullary blood flow by locally formed paracrine agents. Several sections provide perspectives on the complex interactions among the multiple mechanisms responsible for paracrine regulation of the renal microcirculation. This plurality of regulatory interactions highlights the need for experimental strategies that include integrative approaches that allow manifestation of indirect as well as direct influences of these paracrine systems on renal microvascular function.
人们对影响肾微血管功能的多种相互作用旁分泌系统的兴趣呈爆发式增长。本综述首先讨论肾血管控制的膜激活机制。有证据表明，存在调节肾小球前和肾小球后小动脉血管平滑肌细胞的不同激活机制。下一部分论述内皮细胞在肾血管功能控制中的关键作用，并涵盖与一氧化氮及其他内皮衍生因子作用相关的最新研究结果。此部分之后是对源自相邻肾小管结构的血管活性旁分泌系统作用的分析。阐述了上皮细胞与血管网络之间信号的相互作用，以提供对肾血流动力学的反馈调节。由于它们对肾微血管功能调节的贡献已得到充分认识，因此在单独章节中讨论了三种主要的旁分泌系统。描述了与肾内生成的血管紧张素II作用及AT1受体的突出作用相关的最新研究结果。接着讨论了嘌呤能化合物的可能作用。认识到细胞外ATP通过P2受体发挥的新作用以及P1受体更被熟知的功能为进一步研究提供了丰富的素材。在下一部分中，描述了血管活性花生四烯酸代谢产物家族。讨论了直接作用于血管平滑肌细胞以及通过影响内皮细胞和上皮细胞间接发挥作用的多种相互作用功能的可能性。特别关注了与细胞色素P - 450代谢产物血流动力学作用相关的最新进展。最后一部分讨论了可能负责局部形成的旁分泌因子对髓质血流进行差异调节的独特机制。几个章节提供了关于负责肾微循环旁分泌调节的多种机制之间复杂相互作用的观点。这种多种调节相互作用凸显了采用包括综合方法在内的实验策略的必要性，这些方法能够体现这些旁分泌系统对肾微血管功能的间接和直接影响。
