Metoclopramide-induced hyperprolactinemia affects mouse endometrial morphology

Information about the effects of pituitary hyperprolactinemia on endometrium, especially in levels coexisting with absence of amenorrhea in women, is scarce. The interference of high prolactin levels on endometrial morphology was thus investigated in young post-pubertal and adult mice rendered hyperprolactinemic by long-term treatment with metoclopramide (MC). No remarkable differences have been noticed upon light microscopy examination of the endometria comparing young to adult cycling MC-treated mice, except on the max/min diameter ratio, which in young animals was lower than in adults (ANOVA, p < 0.01). Both young and adult MC-treated mice presented an increased number of endometrial glands than their respective controls (ANOVA, p < 0.01). However, young MC-treated animals showed the highest values of endometrial thickness index compared to other groups (ANOVA, p < 0.01). Our results indicate that MC-induced hyperprolactinemia causes mouse endometrium proliferation, mainly in young animals.