Relevance of single nephron studies to human glomerular function.

The preceding article has illustrated a few of the many studies utilizing single nephron micropuncture techniques to identify intrarenal hemodynamic disease patterns, to identify the actions of various vasoactive mediators and thereby allow correlation with disease processes, and to explain the mechanisms underlying interventions which benefit the kidney. Many other uses of these techniques have provided insight into clinical disease pathophysiology, including: studies examining the importance of changes in tubuloglomerular feedback; the role of changes in tubular reabsorption; and studies correlating function with morphologic changes and with in vitro studies. While this review has concentrated on in vivo glomerular micropuncture techniques, a number of other innovative techniques are being used to approach these questions, including studies in isolated perfused tubules, afferent and efferent arterioles, and glomeruli. Accordingly, these studies will continue to provide the hemodynamic context in which other pathophysiologic processes and therapeutic mechanisms are revealed.