ISSN:
0148-7280
Keywords:
PMSG
;
superovulation
;
follicular steroids
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
Our previous study has shown that superovulatory treatment with pregnant mare serum gonadotropin (PMSG) in rats caused marked alterations in ovarian and serum steroid responses and coincidental increase in degenerate oocytes (Yun et al., 1987). This study examined the effects of superovulatory treatment (20 IU PMSG) on follicular steroid contents and oocyte maturation. Immature female rats aged 28-30 days were injected with 4 or 20 IU PMSG and sacrificed at 24, 48, 60, and 72 hr. Compared to control regimen, follicular content of progesterone (P) in superovulated rats significantly (P 〈 .05) increased at 48 hr. Androgen (A) content significantly (P 〈 .01) decreased below control level at 24 hr but significantly (P 〈 .05) increased above control level at 48 hr and 60 hr. There was no significant change in 17β-estradiol (E) content between the two groups. In control regimen, the ratio of A/E sharply decreased and the ratios of P/Eand P/A increased steadily from 24 hr. However, superovulatory regimen showed a consistently steady state in the overall ratios of follicular steroids after 24 hr. Nuclear maturation of the majority of control oocytes recovered from oviducts at 72 hr was synchronized at metaphase II, whereas superovulated oocytes displayed different stages varying from prophase I to metaphase II at 24, 48, and 72 hr. The results provide direct evidence of atypical ovulations in superovulated oocytes with premature or asynchronous nuclear maturation and demonstrate a close relationship between meiotically aberrant oocytes and abnormal follicular steroidogenesis following superovulation with PMSG in rats.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/mrd.1120230306
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