Local effect of thromboxane B2 on the contractility of the human non pregnant uterus.

The effect of intra-uterine instillation of 100 micrograms thromboxane B2 [TXB2] on the contractility of the non-pregnant uterus was studied in 30 subjects during the different phases of the menstrual cycle [menstrual, proliferative, periovulatory and secretory]. Twenty control cases received a similar volume of diluted ethanol. The TXB2 proved to be a powerful uterine stimulant at all phases and the response [maximum elevation in tonus and duration] appeared to be most pronounced in the secretory phase. The implication of these findings in the control of uterine activity is discussed.