Application of the isolated perfused rat kidney in nephrology

Three approaches, each adapted for a specific type of investigation, have been developed for perfusion of isolated rat kidneys. Single-pass perfusion is preferred for physiological or pathophysiological work since the effect of metabolic substrates on sodium transport can be evaluated without the possible curtailing effect of catabolic substrates which can arise when perfusate is recirculated. Recirculation is preferred for biochemical studies since metabolic effects accumulate in time when this approach is employed. The kidney's role in the degradation and framentation of peptide hormones can thus be analyzed. The third approach, recirculation with dialysis, incorporates the advantages of the first two approaches; expensive colloids such as albumin can be used, and the contancy of functional parameters of single-pass perfusion may be achieved.