Effect of Changes in Salt Intake on Arterial Pressure and Renal Function in Partially Nephrectomized Dogs

Abstract

Approximately 70% of the total renal tissue was removed in 11 dogs. Control values were then established for mean arterial pressure, urine and plasma sodium concentrations, blood urea nitrogen, glomerular filtration rate, total body weight, and rate of urine formation for these dogs and for two dogs whose kidneys were left intact. Two of the partially nephrectomized dogs were allowed to drink water for the duration of the study while the other animals were required to drink 0.9% sodium chloride solution for various periods of time. The increased salt intake resulted in a 30% to 40% increase in arterial pressure within 48 to 72 hours; plasma sodium concentration increased concomitantly with the development of hypertension. The elevated pressure could be reduced to normal levels within 24 hours by simply allowing the dogs to drink tap water again. Similar results were obtained in a single dog in which renal function had fortuitously been reduced by chronic pyelonephritis.