Effects of endometriosis, fibroids, and other pathological conditions on muscular contractions in the human fallopian tube

Abstract

Background: Ectopic pregnancy and tubal endometriosis directly affect the fallopian tube structure and function, while ovarian cysts and uterine fibroids may indirectly influence tubal physiology. These conditions are associated with infertility, but their impact on fallopian tube mechanical contractions remains unclear. This study aimed to assess the effects of these pathologies on fallopian tube contractility. Method: Ampulla samples were obtained from women undergoing salpingectomy for benign causes. Based on the menstrual phases, samples were divided into two groups: proliferative (normal proliferative, tubal endometriosis, ovarian cysts, and uterine fibroids) and secretory (normal secretory and ectopic pregnancy). Normal proliferative considered control for the proliferative group, while normal secretory for the ectopic pregnancy. Contractile parameters, maximum contractile force, basal tone, frequency, and amplitude were measured using an isometric force transducer, while in another set of experiments; the oxytocin doses (1 and 10 μM) response was assessed. Smooth muscle organization and structural changes were analyzed through hematoxylin and eosin staining. Result: Compared to the normal proliferative, the tubal endometriosis and ovarian cysts groups showed significantly lower maximum contractile force, basal tone, frequency, and amplitude, along with damaged smooth muscle layers, while uterine fibroids showed decreased frequency and amplitude, with organized muscle structure. Ectopic pregnancy showed higher maximum contractile force and basal tone than normal secretory, with increased frequency and amplitude and disorganized smooth muscle. Oxytocin increased contractility at 1 μM and reduced it at 10 μM in most groups. Conclusion: This study demonstrated that fallopian tube contractions and tissue structure were differentially affected across groups, with increased contractility observed in the ectopic pregnancy group and reduced contractility in the uterine fibroids, ovarian cysts, and tubal endometriosis groups. © The Author(s) 2025. Published by Oxford University Press on behalf of the Society for the Study of Reproduction. All rights reserved.