Effect of Intravenous Administration of Prostaglandin E₁ and F_2α on the Contractility of the Non-Pregnant Human Uterus in Vivo

Abstract

The effect on uterine contractility of prostaglandin E₁ (PGF_2α) and F_2α (PGF_2α) was studied in 19 non-pregnant women. Uterine motility was recorded by the micro balloon method and the prostaglandins administered by single intravenous injections in increasing doses.

1. Doses above threshold levels of both PGE₁ and PGF_2α always resulted in stimulation of the uterus primarily in terms of tone elevation.

2. A short drop of tone during 40–60 seconds immediately following the injection was obtained in a few experiments after high doses of PGE₁. This response preceeded the normal stimulatory effect.

3. The threshold dose for PGE₁ was approximately 20 μg and that for PGF_2α around 50 μg or lower.

4. The non-pregnant uterus is probably more sensitive to PGF_2α than the midpregnant uterus.

5. The number of experiments were too few to allow conclusions as to differences in uterine sensitivity during the various phases of the menstrual cycle.

6. Administration of oxytocin and vasopressin did not enchance the uterine sensitivity to stimulation by PGE₁.