Mullerian Inhibiting Substance in the Adult Rat Ovary During Various Stages of the Estrous Cycle*

Abstract

Mullerian inhibiting substance (MIS) in the adult rat ovary can be detected by immunohistochemistry in the granulosa cells of growing preantral follicles and in the cumulus oophorus and periluminal granulosa cells of antral follicles in estrus, metestrus, diestrus, and proestrus. Neither the corpus luteum nor atreitic follicles stained for MIS. During proestrus, dramatic changes occurred in the large preovulatory antral follicles, which early in the day manifest intense MIS-specific staining in the granulosa cells located close to the oocyte, however, at 2300 h, just before ovulation when the germinal vesicle was extruded to indicate resumed meiotic division, MIS staining waned. When the morphology of the late preovulatory stage was created experimentally in 26-day-old immature ovaries by stimulating 48 h earlier with hCG, the intense staining of the granulosa cells surrounding the oocytes from untreated ovaries was lost in the cumulus cells of such hCG-treated animals. This temporal pattern of MIS staining and the prior demonstration that MIS could inhibit in vitro meiosis of oocytes from untreated immature rats suggest that this regressor, well characterized in the fetal testis, might function in the ovary as a regulator of oocyte maturation and follicular development during the adult reproductive cycle.

A putative role for anti-Müllerian hormone (AMH) in optimising ovarian reserve expenditure

“…Similar patterns occur in non-human primates (Modi et al 2006), mice (Gruijters et al 2003), rats (Ueno et al 1989, Hirobe et al 1994, Baarends et al 1995, Siberian hamsters (Shahed & Young 2013), cows (Monniaux et al 2012), goats (Monniaux et al 2012, Rocha et al 2016, sheep (Bezard et al 1987) and brushtail possums (Juengel et al 2002). AMH expression declines as follicles progress through the large antral stage of folliculogenesis, with little AMH being produced in preovulatory follicles (Ueno et al 1989, Weenen et al 2004, Jeppesen et al 2013. However, AMH expression remains elevated in the cumulus granulosa cells of large follicles until immediately prior to ovulation (Ueno et al 1989, Hirobe et al 1994, Monniaux et al 2012, Merhi et al 2013.…”

“…AMH expression declines as follicles progress through the large antral stage of folliculogenesis, with little AMH being produced in preovulatory follicles (Ueno et al 1989, Weenen et al 2004, Jeppesen et al 2013. However, AMH expression remains elevated in the cumulus granulosa cells of large follicles until immediately prior to ovulation (Ueno et al 1989, Hirobe et al 1994, Monniaux et al 2012, Merhi et al 2013. AMH expression is negligible in atretic follicles (Weenen et al 2004).…”

Activation of dormant ovarian follicles to generate mature eggs

“…1B). At 48 h after treatment, granulosa cells of growing follicles in the treatment group showed increased staining of anti-Mullerian hormone (AMH), a marker for secondary/preantral follicles (11) (Fig. 1C).…”

Developmental expression of four novel serine/threonine kinase receptors homologous to the activin/transforming growth factor‐β type II receptor family

“…4c,d). This is of note because MIS expression by granulosa cells of the cycling rat ovary is greatest in preantral and antral follicles prior to ovulation, particularly in the cell layers closest to the oocyte (Ueno et al, 1989), and because MIS has been shown to inhibit oocyte meiosis in vitro (Takahashi et al, 1986). Again, such signal localization is suggestive that R1 is a candidate MIS receptor.…”