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Delsouc MB, Bronzi CD, Becerra CD, Bonaventura MM, Mohamed FH, Casais M. Ganglionic and ovarian action of acetylcholine during diestrous II in rats. Neuroendocrine control of the luteal regression. Steroids 2019; 148:19-27. [PMID: 31071343 DOI: 10.1016/j.steroids.2019.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 03/28/2019] [Accepted: 04/26/2019] [Indexed: 10/26/2022]
Abstract
Our aim was to investigate if acetylcholine (Ach), added to the celiac ganglion-superior ovarian nerve-ovary system (CG-SON-ovary) or in ovary incubations, modifies the release of progesterone (P4), androstenedione (A2), dopamine (DA), norepinephrine (NE), gonadotropin-releasing hormone (GnRH), and alters the expression of 3β-hydroxysteroid dehydrogenase (3β-HSD), 20α-hydroxysteroid dehydrogenase (20α-HSD), and apoptotic genes in ovarian tissue during the diestrous II (DII) in rats. The CG-SON-ovary system or the ovary alone were removed and placed into separate cuvettes both containing Krebs-Ringer solution (control groups). In experimental groups, 10-6 M Ach was added into the ganglion compartment or into the ovary compartment. P4, A2 and GnRH were measured by RIA, mRNA expression by RT-PCR, and catecholamines by HPLC. In addition, a routine histological technique was applied. In ex-vivo system, 10-6 M Ach into the ganglion compartment decreased P4 and NE release, altered 3β-HSD and 20α-HSD expression, and decreased bax/bcl-2 ratio, while increasing the release of A2 and DA, and bcl-2 expression. In ovary incubations, 10-6 M Ach decreased P4 and GnRH release, decreased 3β-HSD and bcl-2 expression, increased A2 release, increased 20α-HSD and bax expression, and the bax/bcl-2 ratio, and induced disorganization of the corpus luteum structure. The peripheral nervous system protected the ovary from the apoptotic mechanisms while in the ovary incubation the effect was reversed. Our results indicate that Ach in DII regulates steroidogenesis and apoptosis in the ovary, by modulating the concentration of neurotransmitters. In vivo, an alteration in the extrinsic cholinergic innervation of the ovary could disrupt the endocrine control of the reproductive function.
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Affiliation(s)
- María B Delsouc
- Instituto Multidisciplinario de Investigaciones Biológicas de San Luis (IMIBIO-SL), CONICET, Ejército de Los Andes 950, CP D5700HHW, San Luis, Argentina; Laboratorio de Biología de la Reproducción (LABIR), Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Ejército de Los Andes 950, CP D5700HHW, San Luis, Argentina
| | - Cynthia D Bronzi
- Instituto Multidisciplinario de Investigaciones Biológicas de San Luis (IMIBIO-SL), CONICET, Ejército de Los Andes 950, CP D5700HHW, San Luis, Argentina; Laboratorio de Biología de la Reproducción (LABIR), Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Ejército de Los Andes 950, CP D5700HHW, San Luis, Argentina
| | - Cristina Daneri Becerra
- Laboratorio de Biología de la Reproducción (LABIR), Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Ejército de Los Andes 950, CP D5700HHW, San Luis, Argentina
| | - María M Bonaventura
- Instituto de Biología y Medicina Experimental (IBYME), CONICET, Vuelta de Obligado 2490, CP C1428ADN, CABA, Argentina
| | - Fabián H Mohamed
- Cátedra de Histología, Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Ejército de Los Andes 950, CP D5700HHW, San Luis, Argentina
| | - Marilina Casais
- Instituto Multidisciplinario de Investigaciones Biológicas de San Luis (IMIBIO-SL), CONICET, Ejército de Los Andes 950, CP D5700HHW, San Luis, Argentina; Laboratorio de Biología de la Reproducción (LABIR), Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis, Ejército de Los Andes 950, CP D5700HHW, San Luis, Argentina.
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Bu L, Setchell KDR, Lephart ED. Influences of dietary soy isoflavones on metabolism but not nociception and stress hormone responses in ovariectomized female rats. Reprod Biol Endocrinol 2005; 3:58. [PMID: 16250912 PMCID: PMC1276816 DOI: 10.1186/1477-7827-3-58] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2005] [Accepted: 10/26/2005] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND Isoflavones, the most abundant phytoestrogens in soy foods, are structurally similar to 17beta-estradiol. Few studies have examined the nociception and stress hormone responses after consumption of soy isoflavones. METHODS In this study, ovariectomized (OVX) female Long-Evans rats were fed either an isoflavone-rich diet (Phyto-600) or an isoflavone-free diet (Phyto-free). We examined the effects of soy isoflavones on metabolism by measuring body weights, food/water intake, adipose tissue weights as well as serum leptin levels. Also, circulating isoflavone levels were quantified. During chemically induced estrous, nociceptive thresholds were recorded. Then, the animals were subjected to a stressor and stress hormone levels were quantified. RESULTS Body weights were significantly lower in Phyto-600 fed rats compared to Phyto-free values within one week and during long-term consumption of soy isoflavones. Correspondingly, Phyto-600 fed animals displayed significantly less adipose deposition and lower serum leptin levels than Phyto-free values. However, rats on the Phyto-600 diet displayed greater food/water intake compared to Phyto-free levels. No changes in thermal pain threshold or stress hormone levels (ACTH and corticosterone) were observed after activation of the hypothalamic-pituitary-adrenal (HPA) stress axis. CONCLUSION In summary, these data show that consumption of soy isoflavones 1) increases metabolism, demonstrated by significantly decreased body weights, adipose tissue deposition and leptin levels, but 2) does not alter nociception or stress hormone responses, as indexed by thermal pain threshold, serum corticosterone and ACTH levels in chemically-induced estrous OVX rats.
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Affiliation(s)
- Lihong Bu
- Physiology and Developmental Biology Department and Neuroscience Center, Brigham Young University, Provo, Utah, 84602, USA
| | - Kenneth DR Setchell
- Department of Pediatrics, Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Edwin D Lephart
- Physiology and Developmental Biology Department and Neuroscience Center, Brigham Young University, Provo, Utah, 84602, USA
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Mahesh VB, Brann DW. Interaction between ovarian and adrenal steroids in the regulation of gonadotropin secretion. J Steroid Biochem Mol Biol 1992; 41:495-513. [PMID: 1562521 DOI: 10.1016/0960-0760(92)90375-s] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Recent work from our laboratory suggests that a complex interaction exists between ovarian and adrenal steroids in the regulation of preovulatory gonadotropin secretion. Ovarian estradiol serves to set the neutral trigger for the preovulatory gonadotropin surge, while progesterone from both the adrenal and the ovary serves to (1) initiate, (2) synchronize, (3) potentiate and (4) limit the preovulatory LH surge to a single day. Administration of RU486 or the progesterone synthesis inhibitor, trilostane, on proestrous morning attenuated the preovulatory LH surge. Adrenal progesterone appears to play a role in potentiating the LH surge since RU486 still effectively decreased the LH surge even in animals ovariectomized at 0800 h on proestrus. The administration of ACTH to estrogen-primed ovariectomized (ovx) immature rats caused a LH and FSH surge 6 h later, demonstrating that upon proper stimulation, the adrenal can induce gonadotropin surges. The effect was specific for ACTH, required estrogen priming, and was blocked by adrenalectomy or RU486, but not by ovariectomy. Certain corticosteroids, most notably deoxycorticosterone and triamcinolone acetonide, were found to possess "progestin-like" activity in the induction of LH and FSH surges in estrogen-primed ovx rats. In contrast, corticosterone and dexamethasone caused a preferential release of FSH, but not LH. Progesterone-induced surges of LH and FSH appear to require an intact N-methyl-D-aspartate (NMDA) neurotransmission line, since administration of the NMDA receptor antagonist, MK801, blocked the ability of progesterone to induce LH and FSH surges. Similarly, NMDA neurotransmission appears to be a critical component in the expression of the preovulatory gonadotropin surge since administration of MK801 during the critical period significantly diminished the LH and PRL surge in the cycling adult rat. FSH levels were lowered by MK801 treatment, but the effect was not statistically significant. The progesterone-induced gonadotropin surge appears to also involve mediation through NPY and catecholamine systems. Immediately preceding the onset of the LH and FSH surge in progesterone-treated estrogen-primed ovx. rats, there was a significant elevation of MBH and POA GnRH and NPY levels, which was followed by a significant fall at the onset of the LH surge. The effect of progesterone on inducing LH and FSH surges also appears to involve alpha 1 and alpha 2 adrenergic neuron activation since prazosin and yohimbine (alpha 1 and 2 blockers, respectively) but not propranolol (a beta-blocker) abolished the ability of progesterone to induce LH and FSH surges. Progesterone also caused a dose-dependent decrease in occupied nuclear estradiol receptors in the pituitary.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- V B Mahesh
- Department of Physiology and Endocrinology, Medical College of Georgia, Augusta 30912
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Ladosky W, Azambuja HM, Schneider HT. Possible mechanism of action of 2-hydroxylated estradiol on the positive feedback control for LH release in the rat. JOURNAL OF STEROID BIOCHEMISTRY 1983; 19:639-44. [PMID: 6136632 DOI: 10.1016/0022-4731(83)90230-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Evidence was given to support a positive role of 2-hydroxyestradiol on the LH surge. The catecholestrogen may act by its catechol A ring on the nucleus arcuatus COMT, consequently leaving the noradrenaline free. The result may be a longer action on the peptidergic terminal in the median eminence and an increase in the LH secretion by the pituitary. This assumption is supported by the observations that the catecholestrogen effect can be mimicked by homocystein, an aminoacid able also to inhibit COMT activity, having neither a steroid nor a catechol structure. The fact that alpha-MIT is able to prevent homocystein-induced increase in LH suggests that it is acting by protecting the local increase of the catecholamine. After ten years of intensive effort to understand the possible physiological role of the catecholestrogens, attention was mostly paid to its structural similarity to estrogen and a great deal of effort was made to understand its function by acting upon the estrogen receptor in the cytosol. The evidence for catecholestrogen action upon COMT, an outside membrane enzyme involved in the process of catecholamine degradation, supports the idea of a catechol action for 2-OHE2. The present evidence strongly supports the physiological importance of the catechol group in the 2-OHE2 in its action mechanism. However, a true physiological role for the catecholestrogens remains to be solved. The evidence we bring confirms once more that catecholestrogens may have a function and explains a new mechanism of action. However, the basic question concerning the true amount of catecholestrogen existing in the hypothalamic nuclei, either brought by the blood stream or locally produced, still needs to be solved: we cannot say whether the mechanism we described is a functioning one, whether it is just brought about by the experimental increase of the catecholestrogen or the artificial blockage of COMT.
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Wilson PA, Cameron M, Scott DS. Strongyloides ratti in virgin female rats: studies of oestrous cycle effects and general variability. Parasitology 1978; 76:221-7. [PMID: 565912 DOI: 10.1017/s0031182000047806] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
There were no differences in mean intestinal worm burdens 8 days after subcutaneous injection of 4000 infective larvae of Strongyloides ratti into rats in dioestrus, pro-oestrus, oestrus and metoestrus. Thus, changes in the hormonal environment of the migrating larvae dependent on the oestrous cycle did not alter the worms' destination or affect their potential for development. In particular, the results are prima facie evidence that prolactin is not, on its own, responsible for the re-orientation of larvae in the tissues of nursing mothers. Other sources of variability in experimental S. ratti infections are analysed and the 'exact dose' technique offered as a corrective for some procedural errors.
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Ozaki Y, Wurtman RJ, Alonso R, Lynch HJ. Melatonin secretion decreases during the proestrous stage of the rat estrous cycle. Proc Natl Acad Sci U S A 1978; 75:531-4. [PMID: 272672 PMCID: PMC411285 DOI: 10.1073/pnas.75.1.531] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Urine was collected from rats during 12 consecutive daily dark periods and assayed for melatonin and norepinephrine; the phase of the vaginal estrous cycle associated with each urine sample was determined from daily vaginal smears. The proestrous phase of the estrous cycle was consistently associated with significant reductions in the excretions of both compounds. The level of melatonin in any urine sample tended to vary as a function of its norepinephrine content; however, the slope of the curve relating these two compounds in metestrous-diestrous samples differed from that for proestrous-estrous specimens. This difference suggests that factors other than the catecholamine (e.g., gonadal hormones) also affect melatonin secretion. Oophorectomy elevated the melatonin concentration of serum but not that of the pineal; this rise was suppressed by the administration of estrogen plus progesterone. The fate of circulating melatonin (as indicated by the proportion of an exogenous dose excreted into the urine) was not affected by the state of the estrous cycle.
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