N-Acetylcysteine Antagonizes the Development But Does Not Reverse ACTH-Induced Hypertension in the Rat

We investigated the effect of antioxidant N-acetylcysteine (NAC) on adrenocorticotropic hormone (ACTH)-hypertension. Male Sprague-Dawley rats received NAC (10 mg/L) or water 4 days before ACTH/saline treatment for 13 days (prevention study). In a reversal study, NAC commenced on day 8 of ACTH/saline treatment and continued for 5 days. ACTH increased systolic blood pressure (SBP) in water drinking rats (111 ± 1 to 131 ± 3 mmHg, p < 0.001). In the prevention study, NAC + ACTH increased SBP (108 ± 2 to 120 ± 2 mmHg, p < 0.001) but less than ACTH alone (p′ < 0.05). In the reversal study, NAC had no significant effect (132 ± 4 to 124 ± 3 mmHg, ns). Thus, NAC partially prevented but did not reverse ACTH-induced hypertension.