Preovulatory changes in the synthesis of cyclic AMP by rabbit graafian follicles (original) (raw)
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Journal of Endocrinology, 1979
The effects of ovine, porcine and human FSH, and ovine and human LH on the accumulation of cyclic AMP by porcine granulosa cells obtained from follicles at various stages of maturation were investigated. During incubation periods of 15 min, 10 μg ovine FSH pretreated with antiserum to LH or 10 μg human FSH resulted in an 11- to 18-fold, five-to ninefold, and less than a twofold increase in intracellular accumulation of cyclic AMP by granulosa cells from small (1–2 mm), medium (3–5 mm) and large (6–12 mm) follicles respectively. Similar patterns of response occurred with addition of porcine FSH. After incubation for 30 and 60 min with ovine, porcine or human FSH, significant accumulation of cyclic AMP in the incubation medium occurred with cells obtained from small and medium-sized follicles. After 60 min of incubation with FSH the accumulation of cyclic AMP in the incubation medium exceeded the intracellular cyclic AMP levels in granulosa cells from small and medium-sized follicles....
Rat oocyte maturation in vitro: Relief of cyclic AMP inhibition by gonadotropins
Proceedings of the National Academy of Sciences, 1978
The hormone-independent, spontaneous maturation that rat oocytes undergo in vitro can be inhibited by derivatives of cyclic AMP and inhibitors of cyclic nucleotide phosphodiesterase. In this study, we have shown that this inhibition of maturation can be partially relieved by preparations of ovine and rat luteinizing hormone or follicle-stimulating hormone. The ability of gonadotropins to foster the resumption of maturation in cultures of cyclic AMP-inhibited oocytes suggests that this system is suitable for studies of the hormonal control of oocyte development. The dose and time dependency of the response to gonadotropins has been examine in order to study the role of these hormones in oocyte maturation and to compare this effect to other known responses of the cumulus-oocyte complex. These studies show that highly purified preparations of rat gonadotropins are less effective inducr of maturation than the more commonly used, but considerably less purified, preparations of ovine gonadotropins. Almost complete relief of inhibition is observed, however, when the oocytes are exposed to a combination of rat luteinizing hormone and follicle-stimulating hormone. Oocyte maturation was not influenced by the sex steroids progesterone or 17,-estradiol. Our results suggest that: (i) cyclic AMP is involved in the intrafollicular inhibition of oocyte maturation; (ii) both gonadotropins are required for maximal stimulation of the resumption of oocyte meiosis; and (iii) steroids are not involved in this response to gonadotropins.
Comparison between the effect of luteinizing hormone and prostaglandin E1 on ovarian cyclic AMP
Prostaglandins, 1974
Isolated whole ovaries from 23-24 day-old rats were studied in order to compare the effects of prostaglandin E 1 (PGE1) and luteinizing hormone (LH) on ovarian cyclic adenosine 3", 5"-monophosphate (cA1VIP) production. Both substances produced a dose-dependent accumulation of cAMP in the ovarian tissue as well as in the incubation medium. The release of cAMP to the incubation medium was considerable after long periods of incubation (60-120 rain). Time-relationships for LH-and PGEl-effects were different. Maximal cAMP content in the tissue after addition of PGE l was seen already after 5-16 rain of incubation whereas LH gave a maximal response after around 60 rain. Accumulation of cAMP in the medium was approximately linear with time for both LH and PGE 1. Addition of theophylline potentiated the action of PGE 1 and LH but did not change the time-courses of the effects. It is concluded that the accumulation of cAMP in the medium should be considered in studies with various in vitro types of ovarian preparations. It is also pointed out that the different time-courses of the LH-and PGEl-effects make the interpretation of additivity experiments difficult.
Effect of LH on the release of cyclic AMP by the rabbit ovary perfused in vivo and in vitro
Reproduction, 1976
After perfusion of 10 rabbit ovaries in vitro with a modified Krebs bicarbonate buffer containing dextran and glucose, the concentration of cAMP in the perfusion medium was significantly increased 2\m=.\5 min after stimulation with 10 \ g=m\ g LH/ml medium and was higher at 15 and 30 min. Intravenous injection of 100 \ g=m\ g LH/rabbit caused a significant increase of cAMP concentrations in the ovarian venous blood from 8 ovaries 10 min after the injection and the cAMP concentrations were higher after 15 and 30 min. The ovarian blood flow was not changed after the LH injection. It is concluded that perfusion techniques can be useful in analysis of the mechanisms and physiological significance of release of cAMP from the ovary after hormonal stimulation.
The Journal of reproduction and development, 2017
The objective of this study was to compare the cAMP and cGMP levels in cumulus-oocyte complexes (COCs) derived from the middle follicles (MFs, 3-6 mm in diameter) and small follicles (SFs, 1-3 mm in diameter) of pre-pubertal gilts during the first 24-h period of maturation in vitro (IVM). Both cAMP and cGMP levels in MF- and SF-derived oocytes did not change during this period. Although the cAMP levels increased in the COCs at 10 and 20 h after the start of IVM, the levels of cAMP were significantly higher in MF-derived COCs than in SF-derived COCs at 20 h after the start of IVM. On the other hand, the cGMP levels in COCs decreased to basal levels between 10 and 20 h after the start of the IVM, whereas cGMP levels were lower in SF-derived COCs than in MF-derived COCs during the first 10 h. The number of cumulus cells was larger in the MF-derived COCs than in the SF-derived COCs during the first 20-h period of IVM. The estimated cAMP level per cumulus cell at 10 h after the start of ...
In Vitro Effect of Cyclic Adenosine 3′, 5′-Monophosphate (cAMP) on Early Human Ovarian Follicles
Journal of Assisted Reproduction and Genetics, 2000
Purpose : To test the effect of cyclic adenosine 3 , 5 -monophosphate (cAMP) on early human ovarian follicles during prolonged culture period. Methods : Donated ovarian biopsies from 16 women undergoing gynecological laparoscopy were cut into slices and cultured in parallel for 1, 2, or 3 weeks in the presence and the absence of 0.5 mM 8-bromo-cAMP. The developmental stages, sizes, and viability of the follicles were recorded from histological sections of all samples. Results : On day 14, cortical slices cultured with 8-bromo-cAMP showed a significantly higher proportion of secondary follicles (50.0% vs. 20.0%) and a lower proportion of primordial follicles (9.7% vs. 26.7%) when compared with those cultured without 8-bromo-cAMP. On day 21, the proportion of viable follicles in cortical slices with 8-bromo-cAMP treatment was significantly higher than that without 8-bromo-cAMP treatment (79.6% vs. 55.2%). Conclusion : CyclicAMP promoted folliculogenesis and follicle survival during 14-21 days' culture of human ovarian cortical slices.
Mechanism of action of luteinizing hormone and follicle-stimulating hormone on the ovary in vitro
Metabolism, 1977
The mechanism of action of luteinizing folliculogenesis and follicular growth, hormone (LH) and follicle-stimulating hor-oocyte maturation, follicular rupture, and mone (FSH) upon various cell types of the corpus luteum maintenance and steroidomammalian ovary is reviewed. Emphasis genesis. The roles of gonadotropin reis placed upon in vitro studies using organ ceptors, AMP, prostaglandins, protein and cell culture as well as short-term in-kinase, and protein synthesis in these LH cubations. FSH and LH actions upon the and FSH actions are discussed. Intrafollowing ovarian functions are discussed: ovarian regulation of LH and FSH action steroidogenesis and metabolism of the is reviewed, including a discussion of the ovary as a whole and of the isolated possible roles of follicular fluid inhibitors follicle and its component cell types, the upon oocyte maturation and granulosa cell granulosa and thecal cells, as well as luteinization.