Figure 2.

Effect of ET-1 (10⁻⁷ M) on vasoconstriction and [Ca²⁺]_i in mesenteric microvessels of virgin and pregnant rats. Simultaneous measurements of ET-1-induced changes in diameter (A, B) and fura-2 340/380 fluorescence ratio (C, D) were recorded in isolated microvessels from virgin (A, C) and pregnant rats (B, D). Cumulative ET-1-induced vasoconstriction, [Ca²⁺]_i, and vasoconstriction per Δ 340/340 ratio in mesenteric microvessels of virgin (E, G) and pregnant rats (F, H) were presented as means ± SEM, n = 8–12 different rats per group. * Measurements in pregnant rats (F and H) are significantly different (P < 0.05) from corresponding measurements in virgin rats (E and G).