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Dai X, Shi J, Han M, Wang AQ, Wei WH, Yang SM. Effect of photoperiod and 6-methoxybenzoxazolinone (6-MBOA) on the reproduction of male Brandt's voles (Lasiopodomys brandtii). Gen Comp Endocrinol 2017; 246:1-8. [PMID: 28279674 DOI: 10.1016/j.ygcen.2017.03.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 01/12/2017] [Accepted: 03/05/2017] [Indexed: 10/20/2022]
Abstract
Plant secondary metabolite 6-methoxybenzoxazolinone (6-MBOA) has been suggested to stimulate animal reproduction. 6-MBOA is detected in Leymus chinensis, a main diet of Brandt's vole (Lasiopodomys brandtii). We have previously reported a stimulatory effect of 6-MBOA on reproduction of male Brandt's voles under a short-day photoperiod. The goal of this study was to investigate the effect of 6-MBOA on reproductive physiology of male Brandt's voles under a long-day photoperiod and examine if 6-MBOA under this photoperiodic regime altered the reproductive status of male Brandt's voles differently than the short-day photoperiod. Under the long-day photoperiod, a high dose of 6-MBOA decreased KiSS-1 mRNA in the arcuate nucleus (ARC), and we also saw a decrease in circulating levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone (T). Steroidogenic acute regulatory protein (StAR) and cytochrome P45011a1 (CYP11a1) in the testes, and relative testis weight also decreased with 6-MBOA administration. Compared to the short-day photoperiod, animals under the long-day photoperiod exhibited increased body weight as well as all other reproductive parameters. Our results showed that 6-MBOA inhibited the reproduction of male Brandt's vole under a long-day photoperiod, a stark contrast from its stimulatory effects under a short-day photoperiod. The paradoxical effects of 6-MBOA suggest it may act as a partial agonist of melatonin. These results provide insight into the complex interactions between environmental factors such as photoperiod and diet in the control of Brandt's vole reproduction.
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Affiliation(s)
- Xin Dai
- College of Bioscience and Biotechnology, Yangzhou University, 48 East Wenhui Road, Yangzhou 225009, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, PR China
| | - Jia Shi
- College of Bioscience and Biotechnology, Yangzhou University, 48 East Wenhui Road, Yangzhou 225009, PR China
| | - Mei Han
- College of Bioscience and Biotechnology, Yangzhou University, 48 East Wenhui Road, Yangzhou 225009, PR China
| | - Ai Qin Wang
- College of Bioscience and Biotechnology, Yangzhou University, 48 East Wenhui Road, Yangzhou 225009, PR China
| | - Wan Hong Wei
- College of Bioscience and Biotechnology, Yangzhou University, 48 East Wenhui Road, Yangzhou 225009, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, PR China
| | - Sheng Mei Yang
- College of Bioscience and Biotechnology, Yangzhou University, 48 East Wenhui Road, Yangzhou 225009, PR China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, PR China.
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Abstract
Effects of melatonin on the ventral prostate of castrated rats supplemented with testosterone were studied using light microscopy. Stereological measurements were made of volume fractions of acini and stroma and surface fractions of glandular epithelium. From these figures and the weights of the glands, the volumes and surface areas were calculated, as well as the mean epithelial heights, mean acinar diameters, and mean distances between glandular acini. Doses of melatonin were varied, to verify its physiological and pharmacological effects. Castration without hormonal treatments produced atrophic changes, with decreases in acinar and stromal volume and widenings in the mean distances between the acini. None of these measurements differed among intact controls, sham-operated controls, and testosterone-supplemented castrated rats. In the castrated rats receiving both testosterone and melatonin, however, there were changes according to the doses of melatonin given. The animals receiving low doses of melatonin (50 and 400 micrograms daily) showed significant decreases in the volumes of the stroma and epithelium and the height of the epithelium. These stereological changes occurred without a significant reduction in the prostatic weights. The animals receiving the higher dose (800 micrograms daily) of melatonin showed no difference in any measurement compared with those of the testosterone-supplemented castrated rats. In rats receiving 2,000 micrograms of melatonin daily, there were significant reductions in the weights of the prostates and the volumes of the acini. These results suggest a direct action of melatonin on the ventral prostate, and the effects depend on the dose given.
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Affiliation(s)
- W Srivilai
- Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, Thailand
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Withyachumnarnkul B, Limpanawattanakul M, Trakulrungsi W. Retention of radioactive substances in the hypothalamus, anterior pituitary, and reproductive organs of male rats after 3H-melatonin administration. Life Sci 1986; 38:1757-65. [PMID: 3702605 DOI: 10.1016/0024-3205(86)90126-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Radioactive concentrations were determined in serum, lung, hypothalamus, anterior pituitary, testis, and accessory sex organs of adult male rats at 2, 20, 30 and 60 min after intravenous 3H-melatonin administrations. The retention patterns of 3H-melatonin and other radioactive substance (3H-non-melatonin) in these tissues were compared. The anterior pituitary demonstrated best tissue retention with highest concentration of 3H-melatonin. The testis and prostate gland accumulated 3H-non-melatonin in an increasing manner from 2 to 60 min. The radioactive substances were also preferentially and progressively located in the nuclear fraction of the anterior pituitary, hypothalamus, testis, and prostate gland. This study leads to the following suggestions: the anterior pituitary is another target organ of melatonin; melatonin is converted into other active material which exerts its action in the testis and prostate gland; melatonin and its active derivative exert their action through the nuclei of their respective cells.
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Abstract
We studied the effect of hCG, aminoglutethimide and pineal effluent on the basal testosterone secretion by superfused adult rat interstitial cells. The period used to determine the mean rates of release was 120-240 min. after the start of superfusion i.e. when basal secretory rate was stable. A 2 h administration of hCG (10 mUI/ml) induced a rapid increase in testosterone output while aminoglutethimide (100 microM) decreased it. Basal testosterone release was not modified when interstitial cells were superfused with effluent of a chamber containing 1, 2 or 4 pineal glands. These results suggest that pineal secretory products exert no direct acute action on testosterone biosynthesis by rat interstitial cells.
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Richardson SB, Prasad JA, Hollander CS. Acetylcholine, melatonin, and potassium depolarization stimulate release of luteinizing hormone-releasing hormone from rat hypothalamus in vitro. Proc Natl Acad Sci U S A 1982; 79:2686-9. [PMID: 7045869 PMCID: PMC346266 DOI: 10.1073/pnas.79.8.2686] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
We have examined the release of radioimmunoassayable luteinizing hormone-releasing hormone (LH-RH) from fragments of rat medial basal hypothalamus. These fragments were cultured overnight in medium containing serum and then preincubated in groups of three for 10 min in medium resembling cerebrospinal fluid in its electrolyte constituents and containing bacitracin. This was followed by 30-min incubation periods during which some of the hypothalami were exposed to test substances. Potassium depolarization, effected by the addition of 56 mM potassium chloride to the incubation medium, caused a marked stimulation in LH-RH release, but only in the presence of calcium. Acetylcholine at 10 nM and the parasympathomimetic anticholinesterase agent neostigmine at 1 microM markedly stimulated LH-RH release. Hexamethonium, a nicotinic antagonist, at 1 microM abolished the acetylcholine-induced increment in LH-RH release. Melatonin, a pineal indolamine, caused significant stimulation of LH-RH release at a concentration as low as 10 nM. Bacitracin (21 microM) was employed in all these experiments. It had no effect on LH-RH release but did prevent the degradation of LH-RH in this system. We conclude that acetylcholine and melatonin are capable of inducing LH-RH release from the rat medial basal hypothalamus. These actions may account for some of the progonadotropic properties previously ascribed to these agents.
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Abstract
The objective of the present investigation was to determine if melatonin at physiological concentrations might have part of its mechanism of action through enhancement of guanylate cyclase (E.C.4.6.1.2) activity. Melatonin enhanced guanylate cyclase activity two-three fold in rat anterior pituitary, thyroid, testis, ovary, liver and small intestine at the 1 nanomolar concentration. Some stimulation of hepatic guanylate cyclase activity by melatonin was seen at concentrations as low as 1 picomolar. There was no stimulation of guanylate cyclase activity at concentrations below 1 picomolar. Maximal enhancement of guanylate cyclase activity was seen at the 1 nanomolar concentration of melatonin with no further enhancement being observed with increasing the concentration to the micromolar range. Thus, the data in the present investigation indicates that at concentrations at which melatonin is known to cause physiological effects, melatonin does cause an enhancement of the activity of the guanylate cyclase-cyclic GMP system.
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Blask DE, Nodelman JL. An interaction between the pineal gland and olfactory deprivation in potentiating the effects of melatonin on gonads, accessory sex organs, and prolactin in male rats. J Neurosci Res 1980; 5:129-36. [PMID: 7401193 DOI: 10.1002/jnr.490050204] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Male rats (25-26 days of age) housed with 14 hours of light per day (lights on 0600--2000 hours) were either olfactory bulbectomized (rendering them anosmic), bulbectomized plus pinealectomized (Pinx), or left intact. On the day following the operations, intact, anosmic, and anosmic-Pinx animals began receiving single, daily afternoon (1700--1800 hours) subcutaneous injections of 50 microgram of melatonin (MEL) for six weeks, while an additional group of intact controls received injections of diluent. At the end of this period, body, anterior pituitary, testicular, and seminal vesicle weights were significantly reduced in intact-MEL-treated animals. Anosmic animals that had been treated with MEL experienced a further, highly significant, 65%, 90%, and 85% depression in testicular, seminal vesicle, and ventral prostate weights, respectively, as compared with intact control and MEL-treated rats. Additionally, both body and anterior pituitary weights were significantly decreased in MEL-treated, anosmic rats. Anosmic-Pinx rats treated with MEL had organ and body weights that were intermediate between those of intact-MEL and anosmic-MEL-treated animals. Pituitary and serum levels of prolactin (Prl) were significantly lower in anosmic-MEL-treated rats than in intact-MEL-treated groups. Similarly, Prl levels were depressed in the anosmic-Pinx rats treated with MEL; however, serum Prl was not statistically lower than in intact or intact-MEL-treated animals. These results indicate that anosmic male rats have an increased sensitivity to antigonadotrophic and Prl-inhibitory effects of MEL. Futhermore, the data suggest that the presence of the pineal gland in anosmic rats is important in permitting anosmia maximally to sensitize the neuroendocrine-reproductive axis to the antigonadotrophic effects of exogenously administered MEL.
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Leonhardt VH. Ependym und Circumventriculäre Organe. HANDBUCH DER MIKROSKOPISCHEN ANATOMIE DES MENSCHEN 1980. [DOI: 10.1007/978-3-642-81358-0_3] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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Rosenblum IY, Benson B, Bria CF, McDonnell D, Hruby VJ. Localization and chemical characterization of a partially purified bovine pineal antigonadotropin. J Neural Transm (Vienna) 1979; 44:197-220. [PMID: 571457 DOI: 10.1007/bf01253063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
An antigonadotropic substance was partially purified from aqueous extracts of bovine pineal glands by methods of gel filtration, ultrafiltration and ion exchange chromatography. Two biological tests, viz. inhibition of compensatory ovarian hypertrophy and reduction of ventral prostate weight, were used to guide the purification. The partially purified antigonadotropin was characterized chemically using techniques of UV and fluorescence spectrometry, thin layer and paper chromatography, paper electrophoresis and amino acid analysis. The results reveal a diversity of ninhydrin-positive components present in the preparations, including free and peptide-bound amino acids, as well as other unidentified components, but not including any of the commonly occurring indoles, indoleamines or catecholeamines. One peptide, oxidized glutathione, was identified in the most purified material containing the biologically active principle yet pure, synthetric glutathione has no antigonadotropic activity in the biological tests utilized. Although the chemical nature of the bovine pineal antigonadotropin remains in question it may be purified by the methods described. The activity is thought to reside in the extremely small, perhaps trace quantities of residues derived. It is believed that large scale, preparative studies will be required for structural determination.
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Collin JP. Recent advances in pineal cytochemistry. Evidence of the production of indoleamines and proteinaceous substances by rudimentary photoreceptor cells and pinealocytes of Amniota. PROGRESS IN BRAIN RESEARCH 1979; 52:271-96. [PMID: 121470 DOI: 10.1016/s0079-6123(08)62933-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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12
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Trentini GP, Mess B, de Gaetani CF, Ruzsás C. Pineal-brain relationship. PROGRESS IN BRAIN RESEARCH 1979; 52:341-66. [PMID: 398534 DOI: 10.1016/s0079-6123(08)62939-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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13
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Trentini GP, Mess B, De Gaetani CF, Ruzsás C. Effect of melatonin on induction of ovulation in the light- induced constant estrous-anovulatory syndrome and possible role of the brain serotoninergic system. J Endocrinol Invest 1978; 1:305-10. [PMID: 574524 DOI: 10.1007/bf03350974] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Continuous light (CL) induces constant estrous anovulatory (CEA) syndrome and blockade of pineal gland activity. Chronic treatment with metatonin is able to overcome the anovulatory state in about 70% of CL-CEA rats, and the luteinizing effect of melatonin is significantly counteracted either by feeding the animals with a tryptophan-poor diet or by injecting methiothepin, a blocker of central serotoninergic receptors. It appears that melatonin elicits luteinization in CL-CEA rats through the brain serotoninergic system.
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Lapwood K, Florcruz S. Luteinizing hormone and testosterone secretory profiles of boars: Effects of stage of sexual maturation. Theriogenology 1978. [DOI: 10.1016/0093-691x(78)90107-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Saxena PK, Anand K. A comparison of ovarian recrudescence in the catfish, Mystus tengara (Ham.), exposed to short photoperiods, to long photoperiods, and to melatonin. Gen Comp Endocrinol 1977; 33:506-11. [PMID: 598693 DOI: 10.1016/0016-6480(77)90109-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Packard MJ, Packard GC. Antigonadotrophic effect of melatonin in male lizards (Callisaurus draconoides). ACTA ACUST UNITED AC 1977. [DOI: 10.1007/bf01934061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Sackman JW, Reiter RJ. Hyperactivity in the blind-anosmic female rat: role of the pineal gland. Physiol Behav 1977; 18:321-3. [PMID: 559320 DOI: 10.1016/0031-9384(77)90139-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Reiter RJ, Vaughan MK, Rudeen PK, Philo RC. Melatonin induction of testicular recrudescence in hamsters and its subsequent inhibitory action on the antigonadotrophic influence of darkness on the pituitary-gonadal axis. THE AMERICAN JOURNAL OF ANATOMY 1976; 147:235-42. [PMID: 970353 DOI: 10.1002/aja.1001470207] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Exposure of adult male hamsters to light-dark (LD) cycles of 0:24 (in hours) for 12 weeks induced atrophy of the testes and accessory sex organs and a drop in immunoreactive pituitary and plasma prolactin levels. The subsequent exposure of these hamsters to LD 14:10 cycles caused regeneration of the sexual organs and an increase in pituitary LH and prolactin levels. Likewise, the weekly treatment of dark-exposed hamsters with subcutaneous melatonin-beeswax pellets led to regeneration of the peripheral reproductive organs and an increase in pituitary LH and prolactin levels. After gonadal regeneration, complete darkness failed to induce atrophy of the reproductive system indicating that either long photoperiods or melatonin treatment cause the pituitary-gonadal axis to be refractory to the inhibitory influence of darkness.
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Rosenblum IY, Benson B, Hruby VJ. Chemical differences between bovine pineal antigonadotropin and arginine vasotocin. Life Sci 1976; 18:1367-74. [PMID: 940419 DOI: 10.1016/0024-3205(76)90352-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Restoration of fertility in light-deprived female hamsters by chronic melatonin treatment. ACTA ACUST UNITED AC 1976. [DOI: 10.1007/bf00691106] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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