in dogs: EXP3174 (0.1 mg/kg + 0.01 mg/kg/min) or vehicle were infused in anesthetized dogs with recent (8.1 +/- 0.4 days) anterior myocardial infarction.

The response to angiotensin II, measured as the mean force development in response to increasing concentrations of angiotensin II, was recorded in the absence and presence of candesartan, 0.003-10 nmol/l, irbesartan, 1-100 nmol/l, losartan, 1-100 nmol/l, and EXP-3174, 0.01-10 nmol/l, for a period of 90 min. In contrast, irbesartan, losartan, and EXP-3174 all caused a parallel shift of the concentration-response curve. It appeared unlikely that losartan exerted any significant inhibitory effect at therapeutic plasma levels, and the main AT 1 - blocking effect observed after oral losartan is probably exerted by EXP-3174. It was concluded that AT 1 -receptor blockers differ in their ability to inhibit angiotensin II-mediated vascular contraction and that the antagonistic characteristics are similar in vessel preparations of different origins and with different degrees of AT 1 -receptor reserve.