Intrauterine pressure, ischemia markers, and experienced pain during administration of a vasopressin V1a receptor antagonist in spontaneous and vasopressin-induced dysmenorrhea

Background. A model to study the effect of vasopressin V1a antagonist in dysmenorrhea. Methods. A double-blind, randomized, placebo-controlled, cross-over trial was performed. Eight patients with primary dysmenorrhea and eight tubal-ligated, healthy subjects participated on days 1–2 of two consecutive menstruations. At each menstruation a bolus injection of 10 pmol/kg of vasopressin was administered before and during infusion of either 300 µg/min of atosiban or placebo. Intrauterine pressure was measured as area under the curve throughout the experiments. Ischemia markers in plasma and pain recorded by a visual analog scale were measured before and after each vasopressin injection as well as before and after the start of either atosiban or placebo infusion. Results. Vasopressin injections elevated area under the curve in both healthy volunteers and dysmenorrhea subjects. The vasopressin-induced rise in area under the curve was lower during atosiban administration than during infusion of placebo in both gr...