Sodium intake and angiotensin in hypertension induced by chronic NO synthase inhibition in the rat
Jover, B.; Nafrialdi; Herizi, A.; Mimran, A.
Archives des Maladies du Coeur et des Vaisseaux 86(8): 1197-1199
1993
ISSN/ISBN: 0003-9683 PMID: 7510468 Document Number: 420061
The influence of dietary sodium restriction and angiotensin II blockade on hypertension induced by a 25-day period of administration of the inhibitor of nitric oxide synthesis NG-nitro-L-arginine methyl ester (L-NAME: 10 mg/kg twice daily by gavage) was assessed in Wistar rats fed a normal or low sodium diet. In addition, the angiotension II receptor blocker, losartan (30 mg/kg once daily by gavage) was administered prior to and during L-NAME in rats fed the normal sodium diet. Results expressed as mean +/- ESM are presented in the following table: [table: see text] At the end of studies, conscious systolic arterial pressure increased similarly in L-NAME-treated groups maintained on NS or LS intake. Moreover, a 25% reduction in cardiac output due to a decrease in stroke volume was observed in both groups. A slight but significant cardiac hypertrophic response was observed in hypertensive rats irrespective of sodium intake. Losartan totally prevented the development of hypertension as well as the decrease in cardiac output and the cardiac hypertrophy associated with L-NAME treatment in rats on normal sodium intake. In conclusion, hypertension resulting from chronic blockade of nitric oxide synthesis was not affected by dietary sodium restriction. A crucial role for the renin-angiotensin system was demonstrated in this new model of hypertension.