Comparison of dienogest and progesterone effects on uterine contractility in the extracorporeal perfusion model of swine uteri.

ABSTRACT

INTRODUCTION: Endometriosis is associated with hyperperistalsis and dysperistalsis in the uterus, and it has been shown that progesterone leads to a decrease in uterine contractility. The synthetic gestagen dienogest is often administered in women who are receiving conservative treatment for endometriosis, and it may be the treatment of choice. The present study investigated the effects of dienogest on uterine contractility in comparison with the known inhibitory effect of progesterone. MATERIAL AND METHODS: Eighty swine uteri were examined using an established extracorporeal perfusion model. The uteri were perfused for at least 4 hours with progesterone, dienogest, or a modified Krebs-Ringer solution as the control group, with uterine contractions being measured using an intrauterine microchip catheter. The amplitude and frequency of contractions and the area under the curve (AUC), reflecting overall contractility, were measured at two separate locations (the isthmus and fundus). RESULTS: Progesterone led to a significant decrease in the amplitude of uterine contractions and to reduced overall pressure (AUC) at the isthmus and fundus. Dienogest led to a significant decrease in the amplitude of contractions and overall pressure (AUC) in the area of the isthmus, but the decrease near the fundus was not significant. The frequency of uterine contractions was not influenced by either progesterone or dienogest. CONCLUSIONS: These results confirm the known inhibitory effect of progesterone on uterine contractility (relative to amplitude of contractions and overall contractility), affecting the whole organ. Perfusion of the uterus with dienogest also led to a general decrease in uterine contractility similar to the effect of progesterone.