Esomeprazole dilates human omental arteries obtained from normotensive pregnancies. Wire myograph assessment of arterial reactivity following constriction with the vasoconstrictor U44619 (thromboxane agonist), and treatment with 0.1–100 μmol/L esomeprazole magnesium trihydrate (Eso MTH) and esomeprazole magnesium hydrate (Eso MH), compared with vehicle (A,B). Data presented as percentage of relaxation (% relaxation) following normalisation to the maximum relaxation to bradykinin, demonstrating both Eso MTH and Eso MH significantly relaxed vessels at the highest concentration (100 μmol/L) (A). The maximum relaxation induced by Eso MTH or Eso MH show no significant difference to vehicle treated vessels (B). Data expressed as mean ± SEM; significance is indicated by the following ** p < 0.01, **** p < 0.0001 (n = 7). The x-axis is in log10 scale.