The relation between sodium transport and oxygen consumption in isolated perfused rat kidney

A non-filtering isolated perfused rat kidney model was developed to determine renal oxygen consumption in the absence of tubular reabsorption. The oxygen consumption in the absence of filtration was 3.1 +/- 0.8 micron of O2/min/g. This "basal" value was substantially higher than that of 2.0 micron of O2/min/g calculated by extrapolation of a plot of sodium reabsorption vs. oxygen consumption in filtering kidneys. It was also found that ouabain 10(-4) M decreased oxygen consumption in non-filtering kidneys and acetazolamide increased it in a dose dependent fashion. Furosemide did not change "basal" oxygen consumption. In filtering kidneys, the ratio of sodium reabsorbed to oxygen consumed averaged 36.8 muEq of Na/mumole of O2. It is concluded that basal oxygen consumption is not a fixed quantity and can be changed by experimental manipulations thereby changing the relation between transport activity and oxygen consumption.