Isolation and use of specific nephron segments and their cells in biochemical studies

Abstract

Micropuncture and microperfusion of defined isolated nephron segments have provided important information on the localization of different transport systems along the mammalian nephron. As these studies have progressed, an increasingly specialized series of ever smaller nephron segments has become apparent. At present, the nephron is divided into at least 10 to 12 different parts. This heterogeneity within a single nephron is even further complicated by the existence of functionally distinct superficial and deep nephrons. Furthermore, any nephron segment may contain multiple cell types, each of which may subserve different and specific functions within that nephron segment. In addition to the various tubular epithelial cells, the kidney contains cells of the renal vasculature, the interstitium and the lymphatics. Overall then, the kidney is composed of at least 30 different cell types. Most likely this still represents an oversimplification. The enormous problem of isolating a defined cell population from such a heterogenous organ can easily be envisioned. The present paper will provide a brief overview about isolation methods for individual nephron segments and individual cells and some of their applications.