In a rat model of mild DOCA-salt hypertension, global sympathetic nervous system activity was not increased, and fully intact renal nerves were not essential for hypertension development.
Does DOCA-salt administration increase global sympathetic nervous system activity or require intact renal nerves for hypertension development in male Sprague-Dawley rats?
Global sympathetic nervous system activity is not increased, and fully intact renal nerves are not essential for the development of mild DOCA-salt hypertension in rats.
Absolute Event Rate: 128% vs 109%
p-value: p=<0.05
Excess sympathetic nervous system activity (SNA) is linked to human essential and experimental hypertension. To test whether sympathetic activation is associated with a model of deoxycorticosterone acetate (DOCA)-salt hypertension featuring two kidneys and a moderate elevation of blood pressure, we measured whole body norepinephrine (NE) spillover as an index of global SNA. Studies were conducted in chronically catheterized male Sprague-Dawley rats drinking water containing 1% NaCl and 0.2% KCl. After a 7-day surgical recovery and a 3-day control period, a DOCA pellet (50 mg/kg) was implanted subcutaneously in one group of rats (DOCA), while the other group underwent sham implantation (Sham). NE spillover was measured on control day 2 and days 7 and 14 after DOCA administration or sham implantation. During the control period, mean arterial pressure (MAP) was similar in Sham and DOCA rats. MAP was significantly increased in the DOCA group compared with the Sham group after DOCA administration (day 14: Sham = 109 ± 5.3, DOCA = 128 ± 3.6 mmHg). However, plasma NE concentration, clearance, and spillover were not different in the two groups at any time. To determine whether selective sympathetic activation to the kidneys contributes to hypertension development, additional studies were performed in renal denervated (RDX) and sham-denervated (Sham-DX) rats. MAP, measured by radiotelemetry, was similar in both groups during the control and DOCA treatment periods. In conclusion, global SNA is not increased during the development of mild DOCA-salt hypertension, and fully intact renal nerves are not essential for hypertension development in this model.
Kandlikar et al. (Sat,) conducted a other in Mild DOCA-salt hypertension. DOCA and high salt intake vs. Sham implantation was evaluated on Mean arterial pressure (MAP) at day 14 (p=<0.05). In a rat model of mild DOCA-salt hypertension, global sympathetic nervous system activity was not increased, and fully intact renal nerves were not essential for hypertension development.