Effect of endogenous LH secretion on ovarian cyclic AMP and cyclic GMP levels in the rat

Ratner, Albert; Sanborn, Carolyn R.

doi:10.1016/0024-3205(80)90163-0

Cited by 14 publications

(6 citation statements)

References 18 publications

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“…Whole rat ovaries exposed to gonadotropins in vitro respond with decreased levels of cGMP while the levels of cAMP increase (Ratner 1976). Similar changes occur after the LH surge (Ratner & Sanborn 1980) in parallel with the resumption of meiosis. The possible role of cGMP in the regulation of meiosis is poorly understood.…”

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confidence: 77%

Resumption of rat oocyte meiosis is paralleled by a decrease in guanosine 3‘,5’‐cyclic monophosphate (cGMP) and is inhibited by microinjection of cGMP

Törnell

Billig

Hillensjø

1990

Acta Physiologica Scandinavica

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The aim of the present study was to measure the level of cyclic GMP (cGMP) compared with the level of cyclic AMP (cAMP) in rat oocytes during resumption of meiosis I (oocyte maturation) and to microinject these cyclic nucleotides into the oocyte to study their effects on oocyte maturation. Immature oocytes were obtained from prepubertal rats primed with pregnant mare's serum gonadotropin. OOcytes were isolated adn short-term cultured under conditions enabling spontaneous maturation. The levels of cGMP and cAMP decreased in the oocyte during spontaneous maturation (from 0.41 to 0.25 and from 0.64 to 0.42 fmol per oocyte respectively). The decrease was observed during the first hour of culture, and no further decline was seen after 2 h. Microinjection of cGMP or cAMP into isolated immature oocytes delayed the spontaneous maturation, cGMP being slightly more effective than cAMP, whereas 2-deoxy-cAMP (which does not stimulate protein kinase A) did not. These results demonstrate for the first time that the level of cGMP decreases in the oocyte parallel to spontaneous meiosis, as already shown for cAMP. This suggests that cGMP, as well as cAMP, may be of importance for regulating this process. This assumption is further supported by data demonstrating a delay in the maturation of oocytes injected with cGMP.

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mentioning

confidence: 77%

Resumption of rat oocyte meiosis is paralleled by a decrease in guanosine 3‘,5’‐cyclic monophosphate (cGMP) and is inhibited by microinjection of cGMP

Törnell

Billig

Hillensjø

1990

Acta Physiologica Scandinavica

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“…cGMP also has an important regulatory function in oocyte maturation. More than three decades ago, it was reported that ovarian cGMP levels declined in response to LH stimulation in rats (Ratner, 1976; Ratner and Sanborn, 1980) and hamsters (Makris and Ryan, 1978; Hubbard, 1980). It was later shown in rat oocytes that a decrease in oocyte cGMP accompanies GVB (Tornell et al, 1990b), and this has recently been demonstrated in mouse oocytes as well (Norris et al, 2009; Vaccari et al, 2009).…”

Section: Discussionmentioning

confidence: 99%

Mouse versus rat: Profound differences in meiotic regulation at the level of the isolated oocyte

Downs

2011

Molecular Reproduction Devel

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Cumulus cell-enclosed oocytes (CEO), denuded oocytes (DO) or dissected follicles were obtained 44–48 h after priming immature mice (20–23-days-old) with 5 IU or immature rats (25–27-days-old) with 12.5 IU of equine chorionic gonadotropin, and exposed to a variety of culture conditions. Mouse oocytes were more effectively maintained in meiotic arrest by hypoxanthine, dbcAMP, IBMX, milrinone, and 8-Br-cGMP. The guanylate cyclase activator, atrial natriuretic peptide, suppressed maturation in CEO from both species, but mycophenolic acid reversed IBMX-maintained meiotic arrest in mouse CEO with little activity in rat CEO. IBMX-arrested mouse, but not rat, CEO were induced to undergo germinal vesicle breakdown (GVB) by follicle stimulating hormone (FSH) and amphiregulin, while human chorionic gonadotropin (hCG) was ineffective in both species. Nevertheless, FSH and amphiregulin stimulated cumulus expansion in both species. FSH and hCG were both effective inducers of GVB in cultured mouse and rat follicles while amphiregulin was stimulatory only in mouse follicles. Changing the culture medium or altering macromolecular supplementation had no effect on FSH-induced maturation in rat CEO. The AMP-activated protein kinase (AMPK) activator, AICAR, was a potent stimulator of maturation in mouse CEO and DO, but only marginally stimulatory in rat CEO and ineffective in rat DO. The AMPK inhibitor, compound C, blocked meiotic induction more effectively in hCG-treated mouse follicles and heat-treated mouse CEO. Both agents produced contrasting results on polar body formation in cultured CEO in the two species. Active AMPK was detected in germinal vesicles of immature mouse, but not rat, oocytes prior to hCG-induced maturation in vivo; it colocalized with chromatin after GVB in rat and mouse oocytes, but did not appear at the spindle poles in rat oocytes as it did in mouse oocytes. Finally, cultured mouse and rat CEO displayed disparate maturation responses to energy substrate manipulation. These data highlight significant differences in meiotic regulation between the two species, and demonstrate a greater potential in mice for control at the level of the cumulus cell-enclosed oocyte.

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“…This cyclic nucleotide has a myriad of functions in the mammalian ovary (reviewed by LaPolt et al, 2003). About three decades ago it was shown that ovarian cGMP levels decline significantly in rat (Ratner, 1976;Ratner and Sanborn, 1980) and hamster (Makris and Ryan, 1978;Hubbard, 1980) ovaries following luteinizing hormone (LH) stimulation. In addition, an inverse relationship exists between cAMP and cGMP levels (Hubbard, 1983).…”

Section: Cgmp Involvementmentioning

confidence: 99%

Regulation of the G2/M transition in rodent oocytes

Downs¹

2010

Molecular Reproduction Devel

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Regulation of maturation in meiotically competent mammalian oocytes is a complex process involving the carefully coordinated exchange of signals between the somatic and germ cell compartments of the ovarian follicle via paracrine and cell-cell coupling pathways. This review highlights recent advances in our understanding of how such signaling controls both meiotic arrest and gonadotropin-triggered meiotic resumption in competent oocytes and relates them to the historical context. Emphasis will be on rodent systems, where many of these new findings have taken place. A regulatory scheme is then proposed that integrates this information into an overall framework for meiotic regulation that demonstrates the complex interplay between different follicular compartments.

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Effect of endogenous LH secretion on ovarian cyclic AMP and cyclic GMP levels in the rat

Cited by 14 publications

References 18 publications

Resumption of rat oocyte meiosis is paralleled by a decrease in guanosine 3‘,5’‐cyclic monophosphate (cGMP) and is inhibited by microinjection of cGMP

Resumption of rat oocyte meiosis is paralleled by a decrease in guanosine 3‘,5’‐cyclic monophosphate (cGMP) and is inhibited by microinjection of cGMP

Mouse versus rat: Profound differences in meiotic regulation at the level of the isolated oocyte

Regulation of the G2/M transition in rodent oocytes

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