This study examined the effects of two weeks of high NaCl diet on kidney function and dynamic renal blood flow autoregulation (RBFA) in rats with adenine-induced chronic renal failure (ACRF). Male Sprague-Dawley rats received either chow containing adenine or were pair-fed an identical diet without adenine (controls, C). After 10 weeks rats were randomized to either remain on the same diet (0.6% NaCl) or to be switched to high 4% NaCl chow. Two weeks after randomization renal clearance experiments were performed under isoflurane anesthesia and dynamic RBFA, baroreflex sensitivity (BRS), systolic arterial pressure variability (SAPV) and heart rate variability (HRV) were assessed by spectral analytical techniques. Rats with ACRF showed marked reductions in GFR and renal blood flow (RBF) whereas mean arterial pressure and SAPV were significantly elevated. In addition, spontaneous BRS was reduced by approximately 50 % in ACRF animals. High NaCl diet significantly increased transfer function fractional gain values between arterial pressure and RBF in the frequency range of the myogenic response (0.06-0.09 Hz) only in ACRF animals (0.3±4.0 vs. -4.4±3.8 dB, P<0.05) . Similarly, high NaCl diet significantly increased SAPV in the low frequency range only in ACRF animals. To conclude, a two week period of high NaCl diet in ACRF rats significantly impaired dynamic RBFA in the frequency range of the myogenic response and increased SAPV in the low frequency range. These abnormalities may increase the susceptibility to hypertensive end-organ injury and progressive renal failure by facilitating pressure transmission to the microvasculature.