Figure 2. Effect of combined endothelin ET_A and ET_B receptor antagonism on vasomotor responses to thrombin (1 U ml⁻¹) in isolated carotid arteries from neonatal mice .

Arteries were isolated from P1 (newborn) (top), P7 (middle) and P21 (bottom) mice, analysed in a microperfusion system at a P _TM of 20 mmHg, and studied under control conditions or following inhibition of ET_A and ET_B receptors (BQ123 1 μm plus BQ788 1 μm). Responses are expressed as a percentage of the baseline diameter of the arteries (B) and presented as the mean ± SEM for n = 5. Arteries were stably constricted with U46619 (U4) prior to evaluating the effects of thrombin. ^***Significant difference between control and antagonist‐treated arteries (P < 0.001).