Expression of basic fibroblast growth factor and its mRNA in uterine endometrium during the menstrual cycle

To learn more about reproductive neovascularization after menstrual regression of the microvessels in uterine endometrium, the regulation of basic fibroblast growth factor (FGF) and its mRNA expression in the endometria of the menstrual cycle with or without treatment with estradiol dipropionate were determined by enzyme-linked immunosorbent assay (ELISA), and reverse transcription-polymerase chain reaction-Southern blot (RT-PCR-SB), respectively. The endometrial basic FGF level was increased in advance of proliferation, but decreased at the secretory phase. The expression of basic FGF mRNA in endometria during the proliferative phase did not alter, but it was decreased at the secretory phase. Estradiol dipropionate increased the expression of basic FGF and its mRNA in endometria of the secretory phase. Therefore, the constant high level of basic FGF mRNA might contribute to the synthesis and accumulation of basic FGF up to the late proliferative phase, and the accumulated basic FGF might be rapidly consumed in the secretory phase. Furthermore, basic FGF during the proliferative phase could plausibly contribute to capillary neovascularization, which could be regulated by sex steroids.