FUNCTIONAL VASCULAR RENIN-ANGIOTENSIN SYSTEM IN HYPERTENSIVE TRANSGENIC RATS FOR THE MOUSE RENIN GENE REN-2

1. isolated aortic segments from transgenic rats for the mouse renin g ene Ren-2 were more sensitive than those from control Sprague-Dawley o nes to the vasoconstrictions induced by angiotensin II and to the pote ntiation of norepinephrine contractions by this peptide. 2. In transge nic, but not in control aorta, pretreatment with angiotensinogen poten tiated norepinephrine-induced vasoconstrictions, this effect being abo lished by captopril. 3. These results suggest that in the aorta of tra nsgenic rats there is a higher functional tissue renin-angiotensin sys tem that potentiates the vascular reactivity to norepinephrine.