Inhibitory effect of nitric oxide on the renin-angiotensin system in Dahl salt-sensitive rats

1, To explore the role of nitric oxide (NO) in the regulation of the renin-angiotensin system (RAS) in Dahl salt-sensitive (DS) rats, the effects of N-G-nitro-L-arginine methyl ester (L-NAME) on plasma renin activity (PRA), and concentrations of angiotensin (ring)I and AngII in the plasma, aorta and kidney were investigated in DS and Dahl salt-resistant (DR) rats, 2, N-G-Nitro-L-argimine methyl ester (12-18 mg/kg per dag) administration for 1 week increased mean arterial pressure (MAP) in DS and DR rats fed a 0.3% NaCl diet and in DR rats fed an 8% NaCl diet compared with corresponding vehicle (water)-treated groups. However, L-Name administration did not change MAP in DS rats fed an 8% NaCl diet. 3, N-G-Nitro-L-arginine methyl ester administration increased PRA in DS rats fed an 8% NaCl diet, but not in DR rats fed an 8% NaCl diet. N-G-Nitro-L-arginine methyl ester administration increased AngI and AngII concentrations in plasma, aorta and kidney only in DS rats fed an 8% NaCl diet, The ratio of AngI to AngII did not change following L-NAME administration in any rats. 4 These results suggest that NO has an inhibitory role on renin release in DS rats fed a high-salt diet.