Isolated perfused rat kidney and liver combined. A new experimental model

Interaction between hepatic and renal metabolism is found in many endocrine systems. We therefore developed a new experimental model, combining the isolated perfused rat kidney and rat liver. Krebs-Henseleit buffer with bovine serum albumin 67 g X l-1 and amino acids was recirculated to both organs through two rolling pumps, four 8 microns Millipore filters and two specially designed membrane lungs. The kidney was cannulated by a modification of the technique described by Nishiitsutsuji-Uwo 1967 and the liver was cannulated by a modification of the technique described by Hems 1966. Kidney function: Perfusion pressure 12.4 +/- 1.1 kPa (93 +/- 8 mmHg), flow 28 +/- 6 ml X min-1 X g-1, FRNa 94.0 +/- 2.9%, GFR 491 +/- 191 microliters X min-1 X g-1, urine production 48 +/- 34 microliters X min-1 X g-1, FEK 60 +/- 36%. Liver function: Flow 25 ml X min-1 (fixed), portal vein pressure 12 +/- 3 cm H2O, bile flow 0.18 +/- 0.13 ml X h-1, oxygen consumption 2.0 +/- 0.2 mumol X min-1 X g-1. Only minor differences were found between single perfusions (N = 25) and combined perfusions (N = 6). We conclude that it is possible to combine the isolated perfused rat kidney and rat liver without impairment of the function of either.