Abstract:

【Objective】 The distribution and expression variation of 5-HT and 5-HT1A receptors in the uterus of the Sprague Dawley during pregnancy were studied. 【Method】 Thirty mature female SD rats with normal pregnancy were randomly divided into 6 groups: pregnancy 3 days group (3D), pregnancy 5 days group (5D) , pregnancy 7 days group (7D), pregnancy13 days group (13D), pregnancy 19 days group (19D) and the first day of postpartum group (P1). The expression of 5-HT and 5-HT1A R in uterus of the rats during pregnancy cycle were studied by immunohistochemical SP method.【Result】The 5-HT and 5-HT1A R immunoreactive products mainly located in endometrial epithelial cells, the glandular epithelium, vascular endothelial cells, stromal cells, decidual cells, immune cells and muscle fiber. The strongest coloration of 5-HT was in 7D and 13D. The strongest coloration of 5-HT1A R was in 13D. The relative expression of immunoreactive product 5-HT and 5-HT1A R of T-test showed that, compared with the 3D, 5D and P1, the expression of 5-HT in 7D and 13D of endometrium was extremely significantly increased (P＜0.01), compared with the 19D, the expression of 5-HT in 7D and 13D were significantly increased (P＜0.05). Compared with the 7D, the expression of 5-HT in 19D of myometrium was significantly decreased (P＜0.05), compared with the 13D, the expression of 5-HT in 19D of myometrium was extremely significantly decreased (P＜0.01). Compared with the 3D, 5D, 7D and P0, the expression of 5-HT1A R in 13D of endometrium was extremely significantly increased (P＜0.01), Compared with the 7D, expression of 5-HT1A R in 13D of endometrium was significantly increased (P＜0.05). Compared with the 3D, 5D, 7D ,19D and P1, the expression of 5-HT1A R in 13D of myometrium was extremely significantly increased (P＜0.01). Expression of 5-HT and 5-HT1AR in pregnancy had highly significant positive correlation. 【Conclusion】 The expression of 5-HT and 5-HT1A R in the uterus in different pregnancy periods was found to adapt to some certain rules, 5-HT through 5-HT1AR are involved in the regulation of pregnancy.

Key words: 5-HT, 5-HT1A receptors, immunohistochemical SP method, pregnancy, uterus, rats