Fig. 1.
Effect of [Ca2 +]o on pre-contracted tone of rabbit mesenteric arteries. (A) Representative traces showing the effect of [Ca2 +]o on pre-contracted tone induced by 10 μM methoxamine (MO). The left record shows that MO induces a stable vasoconstriction in the presence of 1 mM [Ca2 +]o, whilst the middle and right records show the effect of increasing [Ca2 +]o from 1 mM to 6 mM on endothelium-intact and endothelium-removed vessels respectively. (B) Mean data showing the effect of [Ca2 +]o on MO-induced pre-contraction tone. Each point is from n = 8 animals, with at least n = 3 vessel segments per animal. **p < 0.01, ***p < 0.001.