Reproduction Abstracts

We report the effect of allopregnanolone (ALLO, 3α-hydroxy-5α-pregnan-20-one), on morphological changes and on angiogenesis in the rat ovary. ALLO, one of the best characterized neurosteroids, has effects on the reproductive female biology. First, we previously demonstrated that ALLO inhibited ovulation, secretion of LH and progesterone, increased the prolactin levels, inhibited the female receptivity and apoptosis in rat corpus luteum (CL). Now, we show the effect of ALLO on ovarian structures and angiogenesis 24 h after i.c.v. administration in cycling rats. Angiogenesis is regulated by several protein factors that are heavily regulated and proper vascularization of a tissue is dependent on a relationship between them.

Material and methods: ALLO 6 μM was injected intracerebroventriculary (i.c.v.) during proestrus. Morphometrical analysis and inmunohistochemistry of Von Willebrand (VW) and α-actin were performed on the estrous morning.

Results and discussion: By morphometrical studies of the ovaries, we observed an increase in the number of luteinized unrupted follicles in treated animals compared to controls (P<0.001). ALLO caused an increase in the VW factor and in α-actin protein (P<0.01 and P<0.05, respectively) promoting development and stability of blood vessels in the ovary. These results suggest that ALLO acts as an angiogenic factor and also as a survival factor in CL and follicles. This is the first report that shows the effect of ALLO on the vascular development and stability in the ovary. ALLO could be used as a molecule controlling inappropriate development of ovarian structures and highlighting their role in ovarian physiology.