Effect of relaxin on the decidual cell reaction in the Mongolian gerbil (Meriones unguiculatus)

Abstract

Purpose: Differentiation of endometrial stromal cells into decidual cells occurs during embryo implantation and pregnancy. Recently, it has been reported that relaxin affects the decidualization of cultured human endometrial cells in vitro; however, there has been no study on the decidualization of the Mongolian gerbil (Meriones unguiculatus). The authors demonstrated artificially induced decidualization, and the effect of relaxin on decidualization in gerbils. Methods: Ten-to-twelve-week-old female Mongolian gerbils were ovariectomized, treated with estradiol, progesterone, and relaxin, and the uterine horn was stimulated. On day 10, uterine horns were measured for weight, protein concentration, and the incorporation of 14C-methionine; tissue sections were examined. Interleukin-11 (IL-11) primers were used for RT-PCR to confirm decidualization. Results: Decidualization can be induced artificially in gerbils. In general, the histological observations of gerbil decidual cells were very similar to those of rats. The uterine horn weight, protein content, and protein synthesis from 14C-methionine significantly increased in the relaxin-treated gerbils (P < 0.05). Mast cells in the relaxin-treated uterus had proliferated more than those of the non-relaxin-treated group, which was confirmed by IL-11 expression. Conclusions: We conclude that decidualization can be induced artificially, and relaxin increased weight of uterine horn, protein concentration, protein synthesis and IL-11 expression in gerbils. © 2009 Japan Society for Reproductive Medicine.