Immunohistochemical characterization of telocytes in ratuterus in different reproductive states

Abstract

Background and aim of work Telocytes are a new type of interstitial tissue cells that were recently discovered in the myometrium of nonpregnant uteri and have been suggested to modulate uterine contraction. This work was conducted to extend this research on uteri at different reproductive states and verify whether the morphology and number of telocytes are modified. Materials and methods This study included 24 apparently healthy female albino rats equally classified into four groups: immature rats, adult nonpregnant rats, pregnant rats, and postpartum rats. The middle one-third of the right uterine horns were processed for H&E staining and immunohistochemical detection of telocytes using a c-kit antibody. The count of c-kit-positive telocytes per high-power field in both the endometrium and myometrium was determined and statistically analyzed. Results C-kit-positive telocytes were detected in the endometrium, mainly around the endometrial glands, and in the myometrium. They were oriented parallel to circular smooth muscles while being located predominately on the boundaries of longitudinal muscle bundles. Immature uteri contained a small number of telocytes in both the endometrium and myometrium that significantly increased in adult nonpregnant uteri. Pregnant uteri showed further significant increase in endometrial telocytes but a significant decrease in myometrial telocytes, possibly to prevent preterm delivery. Postpartum uteri showed the highest count of myometrial telocytes, which could reflect their role in postpartum involution. Conclusion Telocytes are present in both the endometrium and myometrium of the rat uterus in different reproductive states. Their functions in the endometrium seem to be glandular support and stromal cell communication, whereas in the myometrium they possibly initiate and coordinate myometrial contraction.