SummaryDogs under barbiturate anesthesia with one kidney acutely denervated and respiring air at greater than atmospheric pressure show two types of renal functional changes. In half the animals studied, a reduction in glomerular filtration rate, renal plasma flow, maximal tubular transport of glucose, urine volume, and sodium excretion occurred in the intact kidney. No change in these functions occurred in the denervated kidney. In the rest of the animals, changes in glomerular filtration, renal plasma flow, and urine formation were smaller, while the TmG increased. The renal functions of these animals appear to have been depressed during control observations, perhaps due to trauma or deep anesthesia. but positive pressure respiration caused partial restoration. Since both kidneys participated, the mechanism must be independent of the renal nerves.