Angiotensin II receptors involved in the enhancement of noradrenergic transmission in the caudal artery of the spontaneously hypertensive rat

Abstract

1 The effects of the AT1 receptor antagonist losartan and the AT2 receptor antagonist PD 123319, on actions of angiotensin II in isolated caudal arteries of spontaneously hypertensive (SH) and age-matched normotensive (Wistar-Kyoto) rats were compared. 2 Angiotensin II (0.1-3 μM) produced concentration-dependent increases in perfusion pressure in artery preparations from both SH and Wistar-Kyoto (WKY) rats, the maximal increase in the SH rat being significantly greater than the increase in WKY rats. The increase in perfusion pressure in preparations from both strains of rats was prevented by losartan (0.1 μM) and unaffected by PD 123319 (0.1 μM), indicating that the vasoconstrictor action of..