Response of Mouse Ovaries in Vivo and in Organ Culture to Pregnant Mare's Serum Gonadotrophin and Human Chorionic Gonadotrophin

Abstract

A series of experiments was carried out to assess the effects of HCG in vivo and in organ culture on oocyte and follicle maturation following treatment with PMSG in vivo. Quantitative histological procedures were used to assess the proportion of follicles in which the oocytes had resumed meiosis beyond the germinal vesicle (diffuse diplotene) stage in response to different doses of hormones. The injection of 3 to 5 i.u. PMSG followed 48 hr later by treatment with 1 to 2 i.u. HCG induced the maximum preovulatory response in ovaries of Schofield albino mice both in vivo and in organ culture. The proportion of large antral follicles with oocytes at metaphase II, however, was much lower in culture than in the intact animal. By contrast, the number of pre-antral and small Graafian follicles increased to a level far higher than in vivo and thus the overall total number of oocytes that progressed beyond the germinal vesicle stage was higher in organ culture.

Response of Mouse Ovaries in Vivo and in Organ Culture to Pregnant Mare's Serum Gonadotrophin and Human Chorionic Gonadotrophin

“…These results are similar to those of Zarrow & Wilson (1961). (Baker & Neal, 1972; Baker, 1973Baker, , 1974. Both PMSG and FSH induce mitotic divisions in granulosa cells within ovaries maintained in organ culture (Pavic, 1963;Fainstat, 1968;Ryle, 1971), but it remains to be established whether these hormones are equally effective in inducing normal development of the follicle.…”

“…As in our previous experiments (e.g. Baker & Neal, 1972;Neal & Baker, 1973, 1974 Table 1). These results are similar to those of Zarrow & Wilson (1961).…”

Ovum morphology after hyperthermic stress during meiotic maturation and ovulation in the mouse

“…These eggs were found peripheral to the cumulus mass and were assumed to be from ovulations in response to the PMSG injection. Eggs ovulated in response to the PMSG remained normal in appearance for 20-32 h and then degenerated before the hCG-induced ovulations, as observed by Neal & Baker (1973). Most of these eggs in the present study were in an advanced stage of degeneration, characterized by a condensed mass of debris peripherally located in an irregularly shaped zona pellucida.…”

Incorporation of Phosphatase Inhibitor in Culture Prompts Growth Initiation of Isolated Non-Growing Oocytes

“…With incorporation of bpV into culture medium, we found increases in both in vitro growth rate and average diameter of oocytes with extension of survival up to 5 days of culture. In the previous reports, the extent of primordial follicle activation differs significantly in different species and with different types of ovarian tissues used [1,7,31–35]. Usually, whole ovaries from neonatal rats or mice are used for in vitro culture, whereas in species with large ovaries, like humans and cattle, only cortical tissues that are rich in primordial follicles are used.…”