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Haematological and chosen biochemical parameter assessment of the antioxidant system in red deer ( Cervus elaphus) blood in early and late pregnancy. J Vet Res 2022; 66:421-426. [PMID: 36349134 PMCID: PMC9597940 DOI: 10.2478/jvetres-2022-0044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 08/11/2022] [Indexed: 11/29/2022] Open
Abstract
Introduction The aim of this study was to investigate changes in haematological parameters and the antioxidant system in the early and late pregnancy of red deer (Cervus elaphus). Material and Methods Blood samples were collected from 30 red deer females 50 days after impregnation and 40 days before calving. Complete blood counts and stained blood smears were assessed. Paraoxonase 1 (PON1), superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR) activities, glutathione disulphide (GSSG), total glutathione, total bilirubin, total protein, albumin, uric acid, malondialdehyde (MDA), beta-hydroxybutyrate (BHB), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides, cholesterol levels and total antioxidant status (TAS) were measured. Results The haematological characteristics of blood collected in the third trimester showed higher haemoglobin levels, haematocrit, mean corpuscular volume (P < 0.05) and a lower mean cell haemoglobin concentration (P < 0.05) in comparison to samples collected on the 50th day after mating. Activity of CAT and MDA, LDL, and triglyceride levels were lower while GR, GSSG, total glutathione, total protein and BHB levels were increased in blood samples drawn in the third trimester compared with the first trimester blood samples. There were no changes in SOD, PON1 activities, TAS, bilirubin, albumin, HDL, cholesterol or uric acid concentrations. Conclusion Red deer’s compensatory mechanisms facilitate its optimal adaptation to seasonal changes evidenced by mild pronounced haematological disturbances and an effective antioxidant system during pregnancy.
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2
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Dardente H, Simonneaux V. GnRH and the photoperiodic control of seasonal reproduction: Delegating the task to kisspeptin and RFRP-3. J Neuroendocrinol 2022; 34:e13124. [PMID: 35384117 DOI: 10.1111/jne.13124] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 02/22/2022] [Accepted: 03/03/2022] [Indexed: 10/18/2022]
Abstract
Synchronization of mammalian breeding activity to the annual change of photoperiod and environmental conditions is of the utmost importance for individual survival and species perpetuation. Subsequent to the early 1960s, when the central role of melatonin in this adaptive process was demonstrated, our comprehension of the mechanisms through which light regulates gonadal activity has increased considerably. The current model for the photoperiodic neuroendocrine system points to pivotal roles for the melatonin-sensitive pars tuberalis (PT) and its seasonally-regulated production of thyroid-stimulating hormone (TSH), as well as for TSH-sensitive hypothalamic tanycytes, radial glia-like cells located in the basal part of the third ventricle. Tanycytes respond to TSH through increased expression of thyroid hormone (TH) deiodinase 2 (Dio2), which leads to heightened production of intrahypothalamic triiodothyronine (T3) during longer days of spring and summer. There is strong evidence that this local, long-day driven, increase in T3 links melatonin input at the PT to gonadotropin-releasing hormone (GnRH) output, to align breeding with the seasons. The mechanism(s) through which T3 impinges upon GnRH remain(s) unclear. However, two distinct neuronal populations of the medio-basal hypothalamus, which express the (Arg)(Phe)-amide peptides kisspeptin and RFamide-related peptide-3, appear to be well-positioned to relay this seasonal T3 message towards GnRH neurons. Here, we summarize our current understanding of the cellular, molecular and neuroendocrine players, which keep track of photoperiod and ultimately govern GnRH output and seasonal breeding.
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Affiliation(s)
- Hugues Dardente
- CNRS, IFCE, INRAE, Université de Tours, PRC, Nouzilly, France
| | - Valérie Simonneaux
- Institute for Cellular and Integrative Neuroscience, University of Strasbourg, Strasbourg, France
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3
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Singh P, Anjum S, Srivastava RK, Tsutsui K, Krishna A. Central and peripheral neuropeptide RFRP-3: A bridge linking reproduction, nutrition, and stress response. Front Neuroendocrinol 2022; 65:100979. [PMID: 35122778 DOI: 10.1016/j.yfrne.2022.100979] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 11/30/2021] [Accepted: 01/06/2022] [Indexed: 02/06/2023]
Abstract
This article is an amalgamation of the current status of RFRP-3 (GnIH) in reproduction and its association with the nutrition and stress-mediated changes in the reproductive activities. GnIH has been demonstrated in the hypothalamus of all the vertebrates studied so far and is a well-known inhibitor of GnRH mediated reproduction. The RFRP-3 neurons interact with the other hypothalamic neurons and the hormonal signals from peripheral organs for coordinating the nutritional, stress, and environmental associated changes to regulate reproduction. RFRP-3 has also been shown to regulate puberty, reproductive cyclicity and senescence depending upon the nutritional status. A favourable nutritional status and the environmental cues which are permissive for the successful breeding and pregnancy outcome keep RFRP-3 level low, whereas unfavourable nutritional status and stressful conditions increase the expression of RFRP-3 which impairs the reproduction. Still our knowledge about RFRP-3 is incomplete regarding its therapeutic application for nutritional or stress-related reproductive disorders.
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Affiliation(s)
- Padmasana Singh
- Department of Zoology, Indira Gandhi National Tribal University, Amarkantak, Anuppur 484886, MP, India
| | - Shabana Anjum
- Department of Chemical Engineering, American University of Sharjah, Sharjah 26666, United Arab Emirates
| | - Raj Kamal Srivastava
- Department of Zoology, Indira Gandhi National Tribal University, Amarkantak, Anuppur 484886, MP, India
| | - Kazuyoshi Tsutsui
- Department of Biology and Center for Medical Life Science, Waseda University, Kagamiyama 1-7-1, Higashi-Hiroshima University 739-8521, Japan
| | - Amitabh Krishna
- Department of Zoology, Banaras Hindu University, Varanasi 221005, UP, India.
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4
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Coen CW, Bennett NC, Holmes MM, Faulkes CG. Neuropeptidergic and Neuroendocrine Systems Underlying Eusociality and the Concomitant Social Regulation of Reproduction in Naked Mole-Rats: A Comparative Approach. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1319:59-103. [PMID: 34424513 DOI: 10.1007/978-3-030-65943-1_3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The African mole-rat family (Bathyergidae) includes the first mammalian species identified as eusocial: naked mole-rats. Comparative studies of eusocial and solitary mole-rat species have identified differences in neuropeptidergic systems that may underlie the phenomenon of eusociality. These differences are found in the oxytocin, vasopressin and corticotrophin-releasing factor (CRF) systems within the nucleus accumbens, amygdala, bed nucleus of the stria terminalis and lateral septal nucleus. As a corollary of their eusociality, most naked mole-rats remain pre-pubertal throughout life because of the presence of the colony's only reproductive female, the queen. To elucidate the neuroendocrine mechanisms that mediate this social regulation of reproduction, research on the hypothalamo-pituitary-gonadal axis in naked mole-rats has identified differences between the many individuals that are reproductively suppressed and the few that are reproductively mature: the queen and her male consorts. These differences involve gonadal steroids, gonadotrophin-releasing hormone-1 (GnRH-1), kisspeptin, gonadotrophin-inhibitory hormone/RFamide-related peptide-3 (GnIH/RFRP-3) and prolactin. The comparative findings in eusocial and solitary mole-rat species are assessed with reference to a broad range of studies on other mammals.
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Affiliation(s)
- Clive W Coen
- Reproductive Neurobiology, Division of Women's Health, Faculty of Life Sciences & Medicine, King's College London, London, UK.
| | - Nigel C Bennett
- Mammal Research Institute, Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Melissa M Holmes
- Department of Psychology, University of Toronto Mississauga, Mississauga, ON, Canada.,Department of Ecology & Evolutionary Biology, University of Toronto, Toronto, Canada.,Department of Cell & Systems Biology, University of Toronto, Toronto, Canada
| | - Christopher G Faulkes
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
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5
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Hadawale KN, Sagarkar S, Bhargava SY. Brain profiling of endogenous Neuropeptide Y (NPY) in distinct reproductive phases of adult male Microhyla ornata. Neurosci Lett 2020; 740:135409. [PMID: 33045276 DOI: 10.1016/j.neulet.2020.135409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 09/22/2020] [Accepted: 10/05/2020] [Indexed: 11/19/2022]
Abstract
Neuropeptide Y(NPY) is known to play a pivotal role in various physiological functions including appetite and reproduction. While studies in mammals, fishes and reptiles suggest a temporal and evolutionary conserved role of NPY, the information in amphibian is scanty. We have investigated the reproductive phase related variations of NPY in the brain of Microhyla ornata (M. ornata), using immunohistochemistry and reverse transcription quantitative PCR (RT-qPCR). The highest expression of NPY peptide was observed in the preoptic area (Poa), nucleus infundibularis ventralis (NIV) and nucleus reticularis isthmi (NRIS) of M. ornata in breeding season compared to pre-breeding as well as post-breeding season. In parallel, highest mRNA levels of NPY were also observed in the breeding season in the middle region of brain that includes hypothalamus of M. ornata. Variation in the levels of NPY peptide and mRNA levels in the brain of M. ornata point towards seasonal control of appetite and reproduction.
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Affiliation(s)
- Kavita N Hadawale
- Department of Zoology, Savitribai Phule Pune University, Ganeshkhind Road, Pune-411 007, India
| | - Sneha Sagarkar
- Department of Zoology, Savitribai Phule Pune University, Ganeshkhind Road, Pune-411 007, India.
| | - Shobha Y Bhargava
- Department of Zoology, Savitribai Phule Pune University, Ganeshkhind Road, Pune-411 007, India.
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6
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Helfer G, Stevenson TJ. Pleiotropic effects of proopiomelanocortin and VGF nerve growth factor inducible neuropeptides for the long-term regulation of energy balance. Mol Cell Endocrinol 2020; 514:110876. [PMID: 32473184 DOI: 10.1016/j.mce.2020.110876] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Revised: 05/14/2020] [Accepted: 05/18/2020] [Indexed: 12/16/2022]
Abstract
Seasonal rhythms in energy balance are well documented across temperate and equatorial zones animals. The long-term regulated changes in seasonal physiology consists of a rheostatic system that is essential to successful time annual cycles in reproduction, hibernation, torpor, and migration. Most animals use the annual change in photoperiod as a reliable and robust environmental cue to entrain endogenous (i.e. circannual) rhythms. Research over the past few decades has predominantly examined the role of first order neuroendocrine peptides for the rheostatic changes in energy balance. These anorexigenic and orexigenic neuropeptides in the arcuate nucleus include neuropeptide y (Npy), agouti-related peptide (Agrp), cocaine and amphetamine related transcript (Cart) and pro-opiomelanocortin (Pomc). Recent studies also indicate that VGF nerve growth factor inducible (Vgf) in the arcuate nucleus is involved in the seasonal regulation of energy balance. In situ hybridization, qPCR and RNA-sequencing studies have identified that Pomc expression across fish, avian and mammalian species, is a neuroendocrine marker that reflects seasonal energetic states. Here we highlight that long-term changes in arcuate Pomc and Vgf expression is conserved across species and may provide rheostatic regulation of seasonal energy balance.
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Affiliation(s)
- Gisela Helfer
- Faculty of Life Sciences, University of Bradford, Bradford, UK
| | - Tyler J Stevenson
- Institute of Biodiversity, Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK.
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7
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Tyler NJC, Gregorini P, Parker KL, Hazlerigg DG. Animal responses to environmental variation: physiological mechanisms in ecological models of performance in deer (Cervidae). ANIMAL PRODUCTION SCIENCE 2020. [DOI: 10.1071/an19418] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Context
Proper assessment of the consequences of environmental variation on animals depends on our ability to predict how they will perform under different circumstances. This requires two kinds of information. We need to know which environmental factors influence animal performance and their mode of action, i.e. whether a given factor acts alone or through interaction with other factors, directly or indirectly, instantaneously or after a delay and so on. This essentially correlative process falls within the domain of ecology. We also need to know what determines the direction, amplitude and limits of animal responses to environmental variation and change. This essentially experimental process falls within the domain of physiology. Physiological mechanisms are frequently poorly integrated within the correlative framework of ecological models. This is evident where programmed responses are attributed to environmental forcing and where the effect of environmental factors is evaluated without reference to the physiological state and regulatory capacity of the animal on which they act.
Aims
Here we examine ways in which the impacts of external (environmental) stimuli and constraints on performance are moderated by the animals (deer) on which they impinge.
Key results
The analysis shows (1) how trade-offs in foraging behaviour, illustrated by the timing of activity under the threat of predation, are modulated by integration of short-term metabolic feedback and animal emotions that influence the motivation to feed, (2) how the influence of thermal and nutritional challenges on performance, illustrated by the effect of weather conditions during gestation on the body mass of reindeer (Rangifer tarandus) calves at weaning, depends on the metabolic state of the female at the time the challenge occurs and (3) how annual cycles of growth, appetite and reproduction in seasonal species of deer are governed by innate circannual timers, such that their responses to seasonal changes in food supply are anticipatory and governed by rheostatic systems that adjust homeostatic set- points, rather than being purely reactive.
Conclusions
Concepts like ‘maintenance’ and ‘energy balance’, which were originally derived from non-seasonal domestic ruminants, are unable to account for annual cycles in metabolic and nutritional status in seasonal deer. Contrasting seasonal phenotypes (fat and anoestrous in summer, lean and oestrous in winter) represent adaptive solutions to the predictable challenges presented by contrasting seasonal environments, not failure of homeostasis in one season and its success in another.
Implications
The analysis and interpretation of responses to environment in terms of interaction between the external stimuli and the internal systems that govern them offer a more comprehensive, multifaceted understanding of the influence of environmental variation on performance in deer and open lines of ecological enquiry defined by non-intuitive aspects of animal function.
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8
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Li L, Lu S, Ma Q, Wan P, Liu C, Yang H, Yang H, Yang Y, Dai R, Shi G. The comparison of reproductive hormone receptor expressions of the sheep ovary and hormone concentrations in two Chinese breeds. Reprod Domest Anim 2019; 54:892-901. [PMID: 31002198 DOI: 10.1111/rda.13441] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Accepted: 04/06/2019] [Indexed: 12/25/2022]
Abstract
The aim of this research was to investigate the changes in reproductive hormone receptor expressions of the ovary and hormone concentrations between oestrous cycle pattern of two different sheep breeds in China. Ovarian tissues were collected from Chinese Merino (Junken type) and Hu sheep with different reproductive states in spring and autumn. Serum samples were assayed for oestrogen (E2), progesterone (P), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) concentrations by radioimmunoassay during spring. The ovarian expression of hormone receptors (ERα, ERβ, PR, LHR and FSHR) was analysed using real-time reverse transcription polymerase chain reaction (RT-PCR). In Chinese Merino, there was no corpora lutea and ovulation point on the surfaces of ovaries in spring and low basal levels of both LH and P in serum. ERα, ERβ and FSHR were expressed significantly higher in Merino ovaries during anoestrus compared with oestrous or luteal phases of Hu sheep (p < 0.05 or p < 0.01). However, both varieties of sheep exhibited a similar tendency to secrete E2 and FSH. Compared with Hu sheep, FSH levels were slightly higher in Merino serum. In Hu sheep, ERα, ERβ, FSHR, LHR and PR expressed in luteal phase ovaries during spring were significantly lower (p < 0.05, p < 0.01 or p < 0.001) than autumn. Interestingly, LHR and PR expressed in anoestrous ovaries were similar to that in oestrous phase of both sheep breeds. The above results suggest that seasonal reproductive sheep increased the expression of E2 and FSH receptors in ovary during spring may enhance the effects of E2 and FSH on follicular development. It is likely that this enhancement prevents the ovary from progressing to the luteal phase.
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Affiliation(s)
- Liangyuan Li
- College of Animal Science and Technology, Shihezi University, Shihezi, China.,State Key Laboratory of Sheep Genetic Improvement and Healthy Production, Xinjiang Academy of Agricultural and Reclamation Sciences, Shihezi, China
| | - Shouliang Lu
- College of Animal Science and Technology, Shihezi University, Shihezi, China.,State Key Laboratory of Sheep Genetic Improvement and Healthy Production, Xinjiang Academy of Agricultural and Reclamation Sciences, Shihezi, China
| | - Qiman Ma
- College of Medicine, Shihezi University, Shihezi, China
| | - Pengcheng Wan
- College of Animal Science and Technology, Shihezi University, Shihezi, China.,State Key Laboratory of Sheep Genetic Improvement and Healthy Production, Xinjiang Academy of Agricultural and Reclamation Sciences, Shihezi, China
| | - Changbin Liu
- College of Animal Science and Technology, Shihezi University, Shihezi, China.,State Key Laboratory of Sheep Genetic Improvement and Healthy Production, Xinjiang Academy of Agricultural and Reclamation Sciences, Shihezi, China
| | - Hanyulu Yang
- College of Animal Science and Technology, Shihezi University, Shihezi, China
| | - Hua Yang
- College of Animal Science and Technology, Shihezi University, Shihezi, China.,State Key Laboratory of Sheep Genetic Improvement and Healthy Production, Xinjiang Academy of Agricultural and Reclamation Sciences, Shihezi, China
| | - Yonglin Yang
- College of Animal Science and Technology, Shihezi University, Shihezi, China.,State Key Laboratory of Sheep Genetic Improvement and Healthy Production, Xinjiang Academy of Agricultural and Reclamation Sciences, Shihezi, China
| | - Rong Dai
- College of Animal Science and Technology, Shihezi University, Shihezi, China.,State Key Laboratory of Sheep Genetic Improvement and Healthy Production, Xinjiang Academy of Agricultural and Reclamation Sciences, Shihezi, China
| | - Guoqing Shi
- College of Animal Science and Technology, Shihezi University, Shihezi, China.,State Key Laboratory of Sheep Genetic Improvement and Healthy Production, Xinjiang Academy of Agricultural and Reclamation Sciences, Shihezi, China
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9
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Dardente H, Wood S, Ebling F, Sáenz de Miera C. An integrative view of mammalian seasonal neuroendocrinology. J Neuroendocrinol 2019; 31:e12729. [PMID: 31059174 DOI: 10.1111/jne.12729] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/29/2019] [Accepted: 04/30/2019] [Indexed: 12/29/2022]
Abstract
Seasonal neuroendocrine cycles that govern annual changes in reproductive activity, energy metabolism and hair growth are almost ubiquitous in mammals that have evolved at temperate and polar latitudes. Changes in nocturnal melatonin secretion regulating gene expression in the pars tuberalis (PT) of the pituitary stalk are a critical common feature in seasonal mammals. The PT sends signal(s) to the pars distalis of the pituitary to regulate prolactin secretion and thus the annual moult cycle. The PT also signals in a retrograde manner via thyroid-stimulating hormone to tanycytes, which line the ventral wall of the third ventricle in the hypothalamus. Tanycytes show seasonal plasticity in gene expression and play a pivotal role in regulating local thyroid hormone (TH) availability. Within the mediobasal hypothalamus, the cellular and molecular targets of TH remain elusive. However, two populations of hypothalamic neurones, which produce the RF-amide neuropeptides kisspeptin and RFRP3 (RF-amide related peptide 3), are plausible relays between TH and the gonadotrophin-releasing hormone-pituitary-gonadal axis. By contrast, the ways by which TH also impinges on hypothalamic systems regulating energy intake and expenditure remain unknown. Here, we review the neuroendocrine underpinnings of seasonality and identify several areas that warrant further research.
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Affiliation(s)
- Hugues Dardente
- Physiologie de la Reproduction et des Comportements, INRA, CNRS, IFCE, Université de Tours, Nouzilly, France
| | - Shona Wood
- Department of Arctic and Marine Biology, The Arctic University of Norway, Tromsø, Norway
| | - Francis Ebling
- School of Life Sciences, University of Nottingham, Nottingham, UK
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10
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Simonneaux V. A Kiss to drive rhythms in reproduction. Eur J Neurosci 2018; 51:509-530. [DOI: 10.1111/ejn.14287] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 10/08/2018] [Accepted: 11/19/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Valérie Simonneaux
- Institut des Neurosciences Cellulaires et IntégrativesCNRSUniversité de Strasbourg Strasbourg France
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11
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Medger K, Bennett NC, Chimimba CT, Oosthuizen MK, Mikkelsen JD, Coen CW. Analysis of gonadotrophin-releasing hormone-1 and kisspeptin neuronal systems in the nonphotoregulated seasonally breeding eastern rock elephant-shrew (Elephantulus myurus). J Comp Neurol 2018; 526:2388-2405. [PMID: 30004584 DOI: 10.1002/cne.24498] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Revised: 06/08/2018] [Accepted: 06/19/2018] [Indexed: 12/18/2022]
Abstract
Of the 18 sub-Saharan elephant-shrew species, only eastern rock elephant-shrews reproduce seasonally throughout their distribution, a process seemingly independent of photoperiod. The present study characterizes gonadal status and location/intensity of gonadotrophin-releasing hormone-1 (GnRH-1) and kisspeptin immunoreactivities in this polyovulating species in the breeding and nonbreeding seasons. GnRH-1-immunoreactive (ir) cell bodies are predominantly in the medial septum, diagonal band, and medial preoptic area; processes are generally sparse except in the external median eminence. Kisspeptin-ir cell bodies are detected only within the arcuate nucleus; the density of processes is generally low, except in the septohypothalamic nucleus, ventromedial bed nucleus of the stria terminalis, arcuate nucleus, and internal and external median eminence. Kisspeptin-ir processes are negligible at locations containing GnRH-1-ir cell bodies. The external median eminence is the only site with conspicuously overlapping distributions of the respective immunoreactivities and, accordingly, a putative site for kisspeptin's regulation of GnRH-1 release in this species. In the nonbreeding season in males, there is an increase in the rostral population of GnRH-1-ir cell bodies and density of GnRH-1-ir processes in the median eminence. In both sexes, the breeding season is associated with increased kisspeptin-ir process density in the rostral periventricular area of the third ventricle and arcuate nucleus; at the latter site, this is positively correlated with gonadal mass. Cross-species comparisons lead us to hypothesize differential mechanisms within these peptidergic systems: that increased GnRH-1 immunoreactivity during the nonbreeding season reflects increased accumulation with reduced release; that increased kisspeptin immunoreactivity during the breeding season reflects increased synthesis with increased release.
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Affiliation(s)
- Katarina Medger
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Nigel C Bennett
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Christian T Chimimba
- Department of Zoology and Entomology, DST-NRF Centre of Excellence for Invasion Biology (CIB), University of Pretoria, Pretoria, South Africa
| | - Maria K Oosthuizen
- Department of Zoology and Entomology, University of Pretoria, Pretoria, South Africa
| | - Jens D Mikkelsen
- Neurobiology Research Unit, Copenhagen University Hospital, Rigshospitalet, Copenhagen, Denmark
| | - Clive W Coen
- Reproductive Neurobiology, Division of Women's Health, Faculty of Life Sciences & Medicine, King's College London, London, United Kingdom
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12
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Kriegsfeld LJ, Jennings KJ, Bentley GE, Tsutsui K. Gonadotrophin-inhibitory hormone and its mammalian orthologue RFamide-related peptide-3: Discovery and functional implications for reproduction and stress. J Neuroendocrinol 2018; 30:e12597. [PMID: 29624758 PMCID: PMC6263162 DOI: 10.1111/jne.12597] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Revised: 03/26/2018] [Accepted: 03/28/2018] [Indexed: 02/06/2023]
Abstract
At the turn of the millennium, a neuropeptide with pronounced inhibitory actions on avian pituitary gonadotrophin secretion was identified and named gonadotrophin-inhibitory hormone (GnIH). Across bird species, GnIH acts at the level of the pituitary and the gonadotrophin-releasing hormone (GnRH) neuronal system to inhibit reproduction. Subsequent to this initial discovery, orthologues of GnIH have been identified and characterised across a broad range of species. In many vertebrates, the actions of GnIH and its orthologues serve functional roles analogous to those seen in birds. In other cases, GnIH and its orthologues exhibit more diverse actions dependent on sex, species, season and reproductive condition. The present review highlights the discovery and functional implications of GnIH across species, focusing on research domains in which the significance of this neuropeptide has been explored most.
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Affiliation(s)
- Lance J. Kriegsfeld
- Department of Psychology, University of California, Berkeley, California 94720, USA
- The Helen Wills Neuroscience Institute, University of California, Berkeley, California 94720, USA
- Corresponding Author: Lance J. Kriegsfeld, Ph.D. Neurobiology Laboratory, Department of Psychology and The Helen Wills Neuroscience Institute, University of California at Berkeley, Berkeley, California 94720-1650, USA, Phone: (510) 642-5148; Fax: (510) 642-5293;
| | - Kimberly J. Jennings
- Department of Psychology, University of California, Berkeley, California 94720, USA
| | - George E. Bentley
- The Helen Wills Neuroscience Institute, University of California, Berkeley, California 94720, USA
- Department of Integrative Biology, University of California, Berkeley, California 94720, USA
| | - Kazuyoshi Tsutsui
- Laboratory of Integrative Brain Sciences, Department of Biology, Waseda University, and Center for Medical Life Science of Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan
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