MILESTONES IN NEPHROLOGY - PREPARATION AND STUDY OF FRAGMENTS OF SINGLE-RABBIT NEPHRONS (REPRINTED FROM AMERICAN JOURNAL OF PHYSIOLOGY, VOL210, PG 1293-1298, 1966)

A method has been developed for the dissection and in vitro study of f ragments of single rabbit nephrons. Fragments of different tubule egme nts .5-4 mm long were dissected from sections of kidney immersed in ox ygenated Ringer solution. Electrolyte and water composition of proxima l tubule fragments were determined after incubation in appropriate sol utions. It was found that isolated proximal tubules maintain large tra nscellular concentration gradients for Na, K, and Cl similar to kidney slices and mixed suspensions of kidney tubules. In order to measure t ranscellular transport, individual tubule segments were perfused and c hanges in the volume and composition of the effluent perfusion fluid m easured. The viability of perfused proximal tubules was demonstrated b y the presence of both active PAH transport and net fluid absorption.