The myometrial response to intra-uterine administration of PGF2alpha and PGE2 in dysmenorrheic women.

Serial recordings of uterine contractility during different phases of the menstrual cycle were carried out in five dysmenorrheic women, and in two subjects during the acute stage of severe dysmenorrheic pain. The sensitivity and reactivity of the uterus to intrauterine administration of small doses of PGF2alpha and PGE2 were studied. A relative insensitivity of the uterus was found in the proliferative phase and around ovulation. The uterus was highly sensitive to the stimulatory effect of PGF2alpha in the secretory phase and at menstruation but probably not more sensitive than in normal women. The corresponding results with PGE2 were rather variable in that small doses did not induce any response or slight stimulation whereas high doses occasionally caused an inhibition in the secretory phase and during menstruation. The results indicate that PGF2alpha may be a significant factor in eliciting uterine hypercontractility and dysmenorrheic pain. Whether the occasional inhibitory effect of PGE2 is of any significant importance in the pathogenesis of dysmenorrhea cannot be stated.