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The major loss of follicles occurs during the small preantral to large preantral follicle transition. Indeed, in FSH null mice follicles do not develop beyond the large preantral stage 5.
Gonadotropin receptors of the ovine ovarian follicle during follicular growth and atresia. How do I know if I've ovulated? Temporal changes associated with the degeneration of the rat oocyte. Possible Encoding for Diverse Physiological Responses.
Some speculations of biochemical markers and mechanisms. Loss of proapoptotic Bax expression in Bax null mice and targeted expression of antiapoptotic Bcl2 in oocytes resulted in fewer atretic small preantral follicles, as determined by the number of oocyte remnants, with more nonatretic follicles 18 , 19.
Here we determined the number of nonatretic and atretic follicles throughout the estrous cycle in detail. As expected, in wild-type females uterine weight changed during the estrous cycle being lowest at metestrus and highest at proestrus. Follicle count was performed as described previously 10 , using serial sections of both ovaries.Shotgun Histology Ovary
The role of follicular smooth muscle cells in hamster ovulation. Greenwald GS, Terranova F: Endocrinology 108: Functional and morphological changes in rat theca cells during atresia. More insight into the mechanisms that control folliculogenesis will lead to a better understanding of reproductive disorders in women. FertilitySmarts Terms: J Reprod Fertil 49: Follicles from the preantral stage onward are removed through follicular atresia, which is driven by granulosa cell apoptosis.
We observed a major decline in follicle numbers during the transition from small preantral to large preantral follicles. Advertisement Hide. Acute gonadotropin deprivation. Surface ultrastructural changes in granulosa cells of atretic follicles.
Indeed, in our previous in vivo study, we observed more growing follicles in AMH null mice in presence of both low and high serum FSH levels.
To determine whether a rise in FSH levels would rescue this increased cohort of growing follicles, AMH null mice of various ages were subjected to a superovulation protocol. A model for the study of androgen effects on follicular atresia and ovulation. Biol Reprod 40: Steroidogenesis in experimentally induced atretic follicles of the hamster: