A model of nitric oxide tubulovascular cross talk in a renal outer medullary cross section.
A model of nitric oxide tubulovascular cross talk in a renal outer medullary cross section.
复制标题
肾外髓质横截面中一氧化氮管血管串扰的模型。
DOI：
10.1152/ajprenal.00208.2006
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
Edwards,Aurelie
中科院分区：
文献类型：
--
作者：
Zhang,Wensheng;Edwards,Aurelie
We developed a two-dimensional model of NO transport in a cross section of the inner stripe (IS) of the rat outer medulla to determine whether tubular and vascular generation of NO result in significant NO concentration (CNO) differences between the periphery and the center of vascular bundles and thereby affect medullary blood flow distribution. Following the approach of Layton and Layton (Layton AT, Layton HE.Am J Physiol Renal Physiol289: F1346–F1366, 2006), the structural heterogeneity of the IS was incorporated in a representative unit consisting of four concentric regions centered on a vascular bundle. Our model suggests that the diffusion distance of NO in the interstitium is limited to a few micrometers. We predict that, under basal conditions, epithelial NO generation raises the average CNOin pericytes surrounding peripheral descending vasa recta (DVR) by a few nanomoles relative to that in pericytes surrounding central DVR. The short descending limbs and long ascending limbs are found to exert the greatest effect on CNOin pericytes; long descending limbs and short ascending limbs only have a moderate effect, whereas outer medullary collecting ducts, which are situated far from the vascular bundle center, do not affect pericyte CNO. Our results suggest that selective stimulation of epithelial NO production should significantly raise the periphery-to-center DVR diameter ratio, thereby increasing the outer medulla-to-inner medulla blood flow ratio. However, concomitant increases in epithelial superoxide (O2−) production would counteract this effect. This model confirms the importance of NO and O2−interactions in mediating tubulovascular cross talk.
