Increased arginase activity in aorta of mineralocorticoid-salt hypertensive rats

The present study was designed, first to investigate aortic arginase activity during the development and the establishment of mineralocorticoid-salt (DOCA-salt) hypertension, and second, to determine the relationship between arginase activity and blood pressure by giving a protein-supplemented diet (50% casein) known to increase hepatic arginase activity. Our results showed that aortic arginase activity in established hypertension of DOCA-salt rats was higher than in normotensive rats. The protein-supplemented diet (50% casein) accelerated the development of DOCA-salt hypertension. There was a positive correlation between arginase activity and the level of blood pressure in these DOCA-salt hypertensive rats fed 50% casein but not in DOCA-salt hypertensive rats on a normal (20% casein) diet. In normotensive rats, the protein-supplemented diet decreased aortic arginase activity and produced no change in systolic blood pressure. Our data suggest that aortic arginase activity is modified in established DOCA-salt hypertension and could participate in the physiopathology of arterial hypertension.