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SUN Y, XUE Y, SUN W, WANG Y, YU J. Effect of nourishing and purging fire Chinese herbal mixture on delaying light-induced premature puberty in rats. J TRADIT CHIN MED 2024; 44:95-102. [PMID: 38213244 PMCID: PMC10774740 DOI: 10.19852/j.cnki.jtcm.20230814.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 11/15/2022] [Indexed: 01/13/2024]
Abstract
OBJECTIVE To elucidate the mechanism of the nourishing Yin and purging fire Chinese herbal mixture (NYPF) in delaying light-induced premature puberty in rats. METHODS Twenty-one days old female Sprague-Dawley rats were randomly assigned to normal group (N), long light exposure group (L), NYPF and normal saline group (NS). Rats in the L, NYPF and NS groups were exposed to 16 h: 350 lux light/8 h: dark, while rats in the N group were exposed to 12 h: 50 lux light/12 h: dark. NYPF and normal saline was administered to the rats in the NYPF group or NS group, respectively, from day 21. Five rats in every group were sacrificed at 9 p.m. on day 28 (P28), on the day when rat's vulva opened in the L group (L-VO), on the day when the first estrous interphase occurred in rats of L group (L-E1), and on the day when the second estrous interphase occurred in rats of L group (L-E2), respectively. RESULITS On day 34, all rats in the L group, 80% of rats in the NS group, 40% of rats in the N group, and 20% of rats in the NYPF group showed complete opening of the vulva. At P28, mRNA level of hypothalamic kisspeptin (Kiss-1) in the L group was significantly higher than that in the N group (P < 0.05). The rats in the L and NS groups had significantly lower hypothalamic arginine-phenylalanine-amide (RFamide)-related peptide 3 (RFRP-3) mRNA levels than those in the N group (P < 0.05), whereas RFRP-3 mRNA level was significantly higher in the NYPF group than that in the L group (P < 0.05). At L-VO, the ovarian index of the L and NS groups was significantly higher than that of the N group (P < 0.05) and estradiol (E2) level of the NYPF group was significantly lower than that of the N and NS groups (P < 0.05); hypothalamic Kiss-1 mRNA level in the L and NS groups was significantly higher than that in the N and NYPF groups (P < 0.05), whereas hypothalamic RFRP-3 mRNA level in the L, NYPF, and NS groups was significantly lower than that in the N group (P < 0.05). At L-E1, E2 level of the L and NS groups was significantly higher than that of the N group (P < 0.01), whereas it was significantly lower in the NYPF group than that of the N, L, and NS groups (P < 0.01), and serum luteinizing hormone level of the L and NS groups was significantly higher than that of the N group (P < 0.05); levels of serum melatonin and ovarian melatonin receptor 1 (MT-1) mRNA in the L, NYPF, and NS groups were significantly lower than those in the N group (P < 0.05). At L-E2, the uterine organ index of the NYPF group was significantly lower than that of the L group (P < 0.05); and ovarian MT-1 mRNA level of the L and NS groups was significantly lower than that in the N group (P < 0.05). CONCLUSIONS NYPF can delay puberty onset in rats exposed to strong light for a prolonged duration, and regulation of the gene expression of Kiss-1 and RFRP-3 in the hypothalamus has been suggested as one of the mechanisms.
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Affiliation(s)
- Yanyan SUN
- 1 Department of Traditional Chinese Medicine, Children's Hospital of Fudan University, Shanghai 201102, China
| | - Yuanyuan XUE
- 2 Department of Pediatrics, Zibo Central Hospital, Zibo 255000, China
| | - Wen SUN
- 1 Department of Traditional Chinese Medicine, Children's Hospital of Fudan University, Shanghai 201102, China
| | - Yonghong WANG
- 1 Department of Traditional Chinese Medicine, Children's Hospital of Fudan University, Shanghai 201102, China
| | - Jian YU
- 1 Department of Traditional Chinese Medicine, Children's Hospital of Fudan University, Shanghai 201102, China
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Carrasco RA, Breen KM. Allostasis in Neuroendocrine Systems Controlling Reproduction. Endocrinology 2023; 164:bqad125. [PMID: 37586095 PMCID: PMC10461221 DOI: 10.1210/endocr/bqad125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 08/08/2023] [Accepted: 08/10/2023] [Indexed: 08/18/2023]
Abstract
Allostasis provides a supporting role to the homeostatic control of biological variables in mammalian species. While the concept of homeostasis is related to the control of variables within a set point or range that are essential to life, allostasis refers to systems that facilitate adaptation to challenges that the organism faces and the new requirements for survival. Essential for such adaptation is the role played by the brain in eliciting neural and neuroendocrine responses. Reproductive function is fundamental for the survival of species but is costly in energetic terms and requires a synchrony with an ever-changing environment. Thus, in many species reproductive function is blocked or delayed over immediate challenges. This review will cover the physiological systems and neuroendocrine pathways that supply allostatic control over reproductive neuroendocrine systems. Light, hypoxia, temperature, nutrition, psychosocial, and immune mediators influence the neuroendocrine control of reproductive functions through pathways that are confluent at the paraventricular nucleus; however, understanding of the integrative responses to these stimuli has not been clarified. Likely, the ultimate consequence of these allostatic mechanisms is the modification of kisspeptin and gonadotropin-releasing hormone neuronal activity, thus compromising reproduction function in the short term, while preserving species survivability.
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Affiliation(s)
- Rodrigo A Carrasco
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Diego, La Jolla, CA 92093-0674, USA
| | - Kellie M Breen
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Diego, La Jolla, CA 92093-0674, USA
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Jameson AN, Siemann JK, Melchior J, Calipari ES, McMahon DG, Grueter BA. Photoperiod Impacts Nucleus Accumbens Dopamine Dynamics. eNeuro 2023; 10:ENEURO.0361-22.2023. [PMID: 36781229 PMCID: PMC9937087 DOI: 10.1523/eneuro.0361-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 12/29/2022] [Accepted: 01/06/2023] [Indexed: 02/15/2023] Open
Abstract
Circadian photoperiod, or day length, changes with the seasons and influences behavior to allow animals to adapt to their environment. Photoperiod is also associated with seasonal rhythms of affective state, as evidenced by seasonality of several neuropsychiatric disorders. Interestingly, seasonality tends to be more prevalent in women for affective disorders such as major depressive disorder and bipolar disorder (BD). However, the underlying neurobiological processes contributing to sex-linked seasonality of affective behaviors are largely unknown. Mesolimbic dopamine input to the nucleus accumbens (NAc) contributes to the regulation of affective state and behaviors. Additionally, sex differences in the mesolimbic dopamine pathway are well established. Therefore, we hypothesize that photoperiod may drive differential modulation of NAc dopamine in males and females. Here, we used fast-scan cyclic voltammetry (FSCV) to explore whether photoperiod can modulate subsecond dopamine signaling dynamics in the NAc core of male and female mice raised in seasonally relevant photoperiods. We found that photoperiod modulates dopamine signaling in the NAc core, and that this effect is sex-specific to females. Both release and uptake of dopamine were enhanced in the NAc core of female mice raised in long, summer-like photoperiods, whereas we did not find photoperiodic effects on NAc core dopamine in males. These findings uncover a potential neural circuit basis for sex-linked seasonality in affective behaviors.
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Affiliation(s)
- Alexis N Jameson
- Neuroscience Graduate Program, Vanderbilt University, Nashville, TN 37232
| | - Justin K Siemann
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232
| | - James Melchior
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232
| | - Erin S Calipari
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232
- Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN 37232
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232
| | - Douglas G McMahon
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232
- Department of Biology, Vanderbilt University, Nashville, TN 37232
| | - Brad A Grueter
- Vanderbilt Brain Institute, Vanderbilt University, Nashville, TN 37232
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232
- Vanderbilt Center for Addiction Research, Vanderbilt University, Nashville, TN 37232
- Department of Pharmacology, Vanderbilt University, Nashville, TN 37232
- Department of Anesthesiology, Vanderbilt University Medical Center, Nashville, TN 37232
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Nazarova GG, Potapov MA, Potapova OF, Novikov EA. Relations between Sexual Maturation of Overwintered Arvicola amphibius (Rodentia, Arvicolinae) Females and Their Physical Condition. BIOL BULL+ 2022. [DOI: 10.1134/s1062359022080131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Constantino DB, Tonon AC, de Oliveira MAB, Amando GR, Freitas JJ, Xavier NB, Ribeiro RJ, Idiart M, Hidalgo MPL. Effects of lighting patterns in pubertal development and metabolism of female wistar rats. Physiol Behav 2021; 243:113641. [PMID: 34748861 DOI: 10.1016/j.physbeh.2021.113641] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 10/16/2021] [Accepted: 11/01/2021] [Indexed: 12/17/2022]
Abstract
Modern lifestyle is characterized by constant exposure to artificial light, which is associated with alterations in biological rhythms, abnormalities to reproductive cycles and metabolic changes. In this study, we aimed to evaluate the effects of four different lighting patterns on puberty timing and on possible metabolic changes in female Wistar rats. Additionally, we developed a machine learning algorithm to automatically classify the stages of the estrous cycle. Adult Wistar rats mated during a week at a photoperiod station where they were exposed to combined red-green-blue lights (RGB) during the photoperiod that varied its spectral composition (i.e., variable color temperature) during the day (RGB-v; N = 14), RGB during the photoperiod with a fixed light color temperature (RGB-f; N = 13) during the whole photoperiod; constant darkness (DD; N = 13) and constant fixed light (LL; N = 15). Experiments were performed only on female litters from postnatal day (PND) 22 to 50. Body weight, puberty onset, estrous cyclicity and serum metabolic parameters were measured. We also collected pictures of vaginal smears to create a dataset of 15,936 images to construct an automatic classifier based on convolutional neural networks. No significant differences were found in the age of vaginal opening; however, the RGB-v group showed a significantly lower number of complete and consecutives cycles. Also, the RGB-f group showed the first complete estrous cycle significantly earlier than the RGB-v group. Female rats housed in LL condition presented significantly lower mean body weight from PND 33 to PDN 47 compared to the other groups. Furthermore, higher levels of plasma triglycerides were found in the DD group compared to RGB-f and RGB-v. HDL levels were significantly lower in RGB-v compared to RGB-f and LL groups. Total cholesterol was significantly lower in RGB-v compared to all groups. Visceral fat was significantly higher in RGB-f compared to the LL group. These results suggest that both changes in photoperiod and lighting quality affect pubertal development and alter lipid profiles and visceral fat accumulation.
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Affiliation(s)
- Débora Barroggi Constantino
- Programa de Pós-Graduação em Psiquiatria e Ciências do Comportamento, Faculdade de Medicina (FAMED), Universidade Federal do Rio Grande de Sul (UFRGS), Porto Alegre, Brazil; Laboratório de Cronobiologia e Sono, Hospital de Clínicas de Porto Alegre (HPCA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil.
| | - André Comiran Tonon
- Programa de Pós-Graduação em Psiquiatria e Ciências do Comportamento, Faculdade de Medicina (FAMED), Universidade Federal do Rio Grande de Sul (UFRGS), Porto Alegre, Brazil; Laboratório de Cronobiologia e Sono, Hospital de Clínicas de Porto Alegre (HPCA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Melissa Alves Braga de Oliveira
- Programa de Pós-Graduação em Psiquiatria e Ciências do Comportamento, Faculdade de Medicina (FAMED), Universidade Federal do Rio Grande de Sul (UFRGS), Porto Alegre, Brazil; Laboratório de Cronobiologia e Sono, Hospital de Clínicas de Porto Alegre (HPCA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Guilherme Rodriguez Amando
- Programa de Pós-Graduação em Psiquiatria e Ciências do Comportamento, Faculdade de Medicina (FAMED), Universidade Federal do Rio Grande de Sul (UFRGS), Porto Alegre, Brazil; Laboratório de Cronobiologia e Sono, Hospital de Clínicas de Porto Alegre (HPCA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Juliana Jury Freitas
- Programa de Pós-Graduação em Psiquiatria e Ciências do Comportamento, Faculdade de Medicina (FAMED), Universidade Federal do Rio Grande de Sul (UFRGS), Porto Alegre, Brazil; Laboratório de Cronobiologia e Sono, Hospital de Clínicas de Porto Alegre (HPCA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Nicoli Bertuol Xavier
- Programa de Pós-Graduação em Psiquiatria e Ciências do Comportamento, Faculdade de Medicina (FAMED), Universidade Federal do Rio Grande de Sul (UFRGS), Porto Alegre, Brazil; Laboratório de Cronobiologia e Sono, Hospital de Clínicas de Porto Alegre (HPCA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Rafael Júnior Ribeiro
- Instituto de Informática, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Marco Idiart
- Departamento de Física, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Maria Paz Loayza Hidalgo
- Programa de Pós-Graduação em Psiquiatria e Ciências do Comportamento, Faculdade de Medicina (FAMED), Universidade Federal do Rio Grande de Sul (UFRGS), Porto Alegre, Brazil; Laboratório de Cronobiologia e Sono, Hospital de Clínicas de Porto Alegre (HPCA), Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
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Postnatal Overnutrition Induces Changes in Synaptic Transmission to Leptin Receptor-Expressing Neurons in the Arcuate Nucleus of Female Mice. Nutrients 2020; 12:nu12082425. [PMID: 32823489 PMCID: PMC7468987 DOI: 10.3390/nu12082425] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 08/05/2020] [Accepted: 08/07/2020] [Indexed: 12/22/2022] Open
Abstract
The adipocyte-derived hormone leptin is a potent neurotrophic factor that contributes to the neural plasticity and development of feeding circuitry, particularly in the arcuate nucleus of the hypothalamus (ARH). Postnatal overnutrition affects leptin secretion and sensitivity, but whether postnatal overnutrition produces changes in the development of the synaptic transmission to ARH neurons is currently unknown. We evaluated the excitatory and inhibitory currents to ARH leptin receptor (LepR)-expressing neurons in prepubertal, pubertal and adult female mice. The effects of postnatal overnutrition in the expression of genes that code ion channels subunits in the ARH were also evaluated. We observed that the transition from prepubertal to pubertal stage is characterized by a rise in both excitatory and inhibitory transmission to ARH LepR-expressing neurons in control mice. Postnatal overnutrition induces a further increase in the excitatory synaptic transmission in pubertal and adult animals, whereas the amplitude of inhibitory currents to ARH LepR-expressing cells was reduced. Postnatal overnutrition also contributes to the modulation of gene expression of N-methyl-D-aspartate, GABAB and ATP-sensitive potassium channel subunits in ARH. In summary, the synaptic transmission to ARH cells is profoundly influenced by postnatal overnutrition. Thus, increased adiposity during early postnatal period induces long-lasting effects on ARH cellular excitability.
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de Miera CS, Beymer M, Routledge K, Krol E, Hazlerigg DG, Simonneaux V. Photoperiodic regulation in a wild-derived mouse strain. J Exp Biol 2020:jeb.217687. [PMID: 34005441 DOI: 10.1242/jeb.217687] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Accepted: 02/10/2020] [Indexed: 12/29/2022]
Abstract
Mus musculus molossinus (MSM) is a wild-derived mouse strain which maintains the ability to synthesize melatonin in patterns reflecting the ambient photoperiod. The objective of this study was to characterize the effects of photoperiodic variation on metabolic and reproductive traits, and the related changes in pituitary-hypothalamic gene expression in MSM mice. MSM mice were kept in long (LP) or short photoperiod (SP) for 6 weeks. Our results demonstrate that MSM mice kept in LP, as compared to mice kept in SP, display higher expression of genes encoding thyrotropin (TSH) in the pars tuberalis, thyroid hormone deiodinase 2 (dio2) in the tanycytes, RFamide-related peptide (RFRP3) in the hypothalamus and lower expression of dio3 in the tanycytes, along with larger body and reproductive organ mass. Additionally, to assess the effects of the gestational photoperiodic environment on the expression of these genes, we kept MSM mice in LP or SP from gestation and studied offspring. We show that the gestational photoperiod affects the TSH/dio pathway in newborn MSM mice in a similar way to adults. This result indicates a transgenerational effect of photoperiod from the mother to the fetus in utero. Overall, these results indicate that photoperiod can influence neuroendocrine regulation in a melatonin-proficient mouse strain, in a manner similar that documented in other seasonal rodent species. MSM mice may therefore become a useful model for research into the molecular basis of photoperiodic regulation of seasonal biology.
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Affiliation(s)
- Cristina Sáenz de Miera
- Institute for Cellular and Integrative Neuroscience, University of Strasbourg, 67000, Strasbourg, France
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, Scotland, UK
| | - Matthew Beymer
- Institute for Cellular and Integrative Neuroscience, University of Strasbourg, 67000, Strasbourg, France
| | - Kevin Routledge
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, Scotland, UK
| | - Elżbieta Krol
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, Scotland, UK
| | - David G Hazlerigg
- School of Biological Sciences, University of Aberdeen, Aberdeen AB24 2TZ, Scotland, UK
- Department of Arctic and Marine Biology, Faculty of Biosciences, Fisheries and Economy, University of Tromsø, 9037 Tromsø, Norway
| | - Valerie Simonneaux
- Institute for Cellular and Integrative Neuroscience, University of Strasbourg, 67000, Strasbourg, France
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Bohlen TM, Zampieri TT, Furigo IC, Teixeira PDS, List EO, Kopchick JJ, Donato J, Frazao R. Central growth hormone signaling is not required for the timing of puberty. J Endocrinol 2019; 243:JOE-19-0242.R1. [PMID: 31470413 PMCID: PMC6994354 DOI: 10.1530/joe-19-0242] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Accepted: 08/30/2019] [Indexed: 12/11/2022]
Abstract
Growth hormone (GH) is a key factor in the regulation of body growth, as well as a variety of other cellular and metabolic processes. Neurons expressing kisspeptin and leptin receptors (LepR) have been shown to modulate the hypothalamic-pituitary-gonadal (HPG) axis and are considered GH-responsive. The presence of functional GH receptors (GHR) in these neural populations suggests that GH may regulate the HPG axis via a central mechanism. However, there have been no studies evaluating whether or not GH-induced intracellular signaling in the brain plays a role in the timing of puberty or mediates the ovulatory cycle. Towards the goal of understanding the influence of GH on the central nervous system as a mediator of reproductive functions, GHR ablation was induced in kisspeptin and LepR expressing cells or in the entire brain. The results demonstrated that GH signaling in specific neural populations can potentially modulate the hypothalamic expression of genes related to the reproductive system or indirectly contribute to the progression of puberty. GH action in kisspeptin cells or in the entire brain was not required for sexual maturation. On the other hand, GHR ablation in LepR cells delayed puberty progression, reduced serum leptin levels, decreased body weight gain and compromised the ovulatory cycle in some individuals, while the lack of GH effects in the entire brain prompted shorter estrous cycles. These findings suggest that GH can modulate brain components of the HPG axis, although central GH signaling is not required for the timing of puberty.
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Affiliation(s)
- Tabata M Bohlen
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP – Brazil
| | - Thais T Zampieri
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP – Brazil
| | - Isadora C. Furigo
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP – Brazil
| | - Pryscila DS Teixeira
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP – Brazil
| | - Edward O. List
- Edison Biotechnology Institute and Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, 45701 – USA
| | - John J. Kopchick
- Edison Biotechnology Institute and Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, 45701 – USA
| | - Jose Donato
- Department of Physiology and Biophysics, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP – Brazil
| | - Renata Frazao
- Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP – Brazil
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Evans MC, Anderson GM. Integration of Circadian and Metabolic Control of Reproductive Function. Endocrinology 2018; 159:3661-3673. [PMID: 30304391 DOI: 10.1210/en.2018-00691] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 10/03/2018] [Indexed: 12/11/2022]
Abstract
Optimal fertility in humans and animals relies on the availability of sufficient metabolic fuels, information about which is communicated to the brain via levels of the hormones leptin and insulin. The circadian clock system is also critical; this input is especially evident in the precise timing of the female-specific surge of GnRH and LH secretion that triggers ovulation the next day. Chronodisruption and metabolic imbalance can both impair reproductive activity, and these two disruptions exacerbate each other, such that they often occur simultaneously. Kisspeptin neurons located in the anteroventral periventricular nucleus of the hypothalamus are able to integrate both circadian and metabolic afferent inputs and use this information to modulate the timing and magnitude of the preovulatory GnRH/LH surge. In an environment in which exposure to high caloric diets and chronodisruptors such as artificial night lighting, shift work, and transmeridian travel have become the norm, the implications of these factors for couples struggling to conceive deserve closer attention and more public education.
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Affiliation(s)
- Maggie C Evans
- Centre for Neuroendocrinology and Department of Anatomy, University of Otago School of Biomedical Sciences, Dunedin, New Zealand
| | - Greg M Anderson
- Centre for Neuroendocrinology and Department of Anatomy, University of Otago School of Biomedical Sciences, Dunedin, New Zealand
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Hoffmann HM. Determination of Reproductive Competence by Confirming Pubertal Onset and Performing a Fertility Assay in Mice and Rats. J Vis Exp 2018. [PMID: 30371660 DOI: 10.3791/58352] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Assessment of reproductive competence is critical for understanding the impact of a treatment or genetic manipulation on the reproductive axis, also termed the hypothalamic-pituitary-gonadal axis. The reproductive axis is a key integrator of environmental and internal input adapting fertility to favorable conditions for reproduction. Prior to embarking upon a fertility study in mice and rats, sexual maturity is evaluated to exclude the possibility that the observed reproductive phenotypes are caused by delayed or absent pubertal onset. This protocol describes a non-invasive approach to assess pubertal onset in males through the determination of preputial separation, and in females through vaginal opening and first estrus. After the confirmation of the completion of puberty and the achievement of sexual maturity, a fertility study can be initiated. The procedure describes the optimal breeding conditions for mice and rats, how to set up a fertility study, and what parameters to evaluate and determine if the treatment or gene deletion has an impact on fertility.
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