Oestrogen peaks at about 11am on the day of proestrus.

During proestrus and estrus, females may have a clear to bloody discharge.

They discovered that cell proliferation peaks during proestrus, a time when estrogen levels are highest.

Results Three of four exposed females expressed estrus by 130 days; a fourth was in proestrus, and the fifth remained anestrous.

Estradiol levels are high on proestrus rats and return to low levels on diestrus rats.

The first stage of the reproductive cycle is proestrus, in which eggs in the ovaries begin to mature and estrogen levels begin to rise.

Also, proestrus rats have significantly higher synapse density in VMN than diestrus rats.

The volume of cell bodies within VMN in proestrus rats and male rats is larger than diestrus rats.

This observation suggests a burst of FS gene activity that may be associated with the preovulatory surge of LH during proestrus.

A set of follicles start to develop near the end of proestrus and grow at a nearly constant rate until the beginning of the subsequent estrus when the growth rates accelerate eightfold.

This increased size of developing follicles in exposed opossums is similar in magnitude to that seen in the pre-Graafian follicles of rats between diestrus and proestrus [ 23 ] .

In the theca, some TIC and TE cells showed BMPR-IB expression with the highest levels appearing in dominant follicles at proestrus (Table 1, Fig.