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Drummond JB, Soares BS, Pedrosa W, Vieira ELM, Teixeira AL, Christ-Crain M, Ribeiro-Oliveira A. Copeptin response to hypoglycemic stress is linked to prolactin activation in children. Pituitary 2020; 23:681-690. [PMID: 32851504 DOI: 10.1007/s11102-020-01076-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
PURPOSE The physiological role of arginine vasopressin (AVP) in the acute stress response in humans and especially in children is unclear. The aim of this study was to explore the interaction between copeptin, a well-established surrogate marker of AVP release, and anterior pituitary hormone activation in response to acute hypoglycemic stress in children and adolescents. METHODS We conducted an exploratory single center study involving 77 children and adolescents undergoing insulin-induced hypoglycemia. Blood levels of copeptin, ACTH, cortisol, GH, prolactin, interleukin-6 (IL-6), adrenaline and noradrenaline were determined at baseline and after insulin-induced hypoglycemia. RESULTS Basal plasma levels of copeptin (median: 5.2 pmol/L) increased significantly after hypoglycemia (median 9.7 pmol/L; P < 0.0001). Subjects with insufficient HPA axis response or severe GH deficiency had lower hypoglycemia-induced copeptin increase (median: 2.3 pmol/L) compared with individuals with intact pituitary response (median: 5.2 pmol/L, P = 0.02). Copeptin increase correlated significantly with the maximal increase of ACTH (rs = 0.30; P = 0.010), cortisol (rs = 0.33; P = 0.003), prolactin (rs = 0.25; P = 0.03), IL-6 (rs = 0.35; P = 0.008) and with BMI-SDS (rs = - 0.28, P = 0.01). In multivariate regression analysis, prolactin increase was the only independent variable associated with copeptin increase (P = 0.0004). CONCLUSION Our data indicate that: (1) hypoglycemic stress elicits a marked copeptin response in children and adolescents, pointing out its role as an acute stress marker in this population; (2) stress-induced AVP/copeptin release is associated with anterior pituitary activation, mainly a prolactin response.
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Affiliation(s)
- Juliana B Drummond
- Laboratory of Endocrinology, Federal University of Minas Gerais, Av. Alfredo Balena, 190, Belo Horizonte, Minas Gerais, Brazil
| | - Beatriz S Soares
- Laboratory of Endocrinology, Federal University of Minas Gerais, Av. Alfredo Balena, 190, Belo Horizonte, Minas Gerais, Brazil
| | - William Pedrosa
- Hermes Pardini Institute, Belo Horizonte, Minas Gerais, Brazil
| | - Erica L M Vieira
- Interdisciplinary Laboratory of Medical Investigation, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Antonio L Teixeira
- Interdisciplinary Laboratory of Medical Investigation, Federal University of Minas Gerais, Belo Horizonte, Brazil
- Immunopsychiatry Laboratory & Neuropsychiatry Program, Department of Psychiatry & Behavioral Science, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, USA
| | | | - Antonio Ribeiro-Oliveira
- Laboratory of Endocrinology, Federal University of Minas Gerais, Av. Alfredo Balena, 190, Belo Horizonte, Minas Gerais, Brazil.
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Martos-Sitcha JA, Campinho MA, Mancera JM, Martínez-Rodríguez G, Fuentes J. Vasotocin and isotocin regulate aquaporin 1 function in the sea bream. J Exp Biol 2015; 218:684-93. [DOI: 10.1242/jeb.114546] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
ABSTRACT
Aquaporins (AQPs) are specific transmembrane water channels with an important function in water homeostasis. In terrestrial vertebrates, AQP2 function is regulated by vasopressin (AVP) to accomplish key functions in osmoregulation. The endocrine control of aquaporin function in teleosts remains little studied. Therefore, in this study we investigated the regulatory role of vasotocin (AVTR) and isotocin (ITR) receptors in Aqp1 paralog gene function in the teleost gilthead sea bream (Sparus aurata). The complete coding regions of Aqp1a, Aqp1b, AVTR V1a2-type, AVTR V2-type and ITR from sea bream were isolated. A Xenopus oocyte-swelling assay was used to functionally characterize AQP1 function and regulation by AVT and IT through their cognate receptors. Microinjection of oocytes with Aqp1b mRNA revealed regulation of water transport via PKA (IBMX+forskolin sensitive), whereas Aqp1a mRNA injection had the same effect via PKC signaling (PDBU sensitive). In the absence of expressed receptors, AVT and IT (10−8 mol l−1) were unable to modify AQP1 function. AVT regulated AQP1a and AQP1b function only when the AVTR V2-type was co-expressed. IT regulated AQP1a function, but not AQP1b, only when ITR was present. Considering that Aqp1a and Aqp1b gene expression in the sea bream intestine is highly salinity dependent in vivo, our results in ovo demonstrate a regulatory role for AVT and IT in AQP1 function in the sea bream in the processing of intestinal fluid to achieve osmoregulation.
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Affiliation(s)
- Juan Antonio Martos-Sitcha
- Centre of Marine Sciences (CCMar), Universidade do Algarve, Campus de Gambelas, Faro 8005-139, Portugal
- Departamento de Biología, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Puerto Real, Cádiz E-11510, Spain
- Instituto de Ciencias Marinas de Andalucía, Consejo Superior Investigaciones Científicas (ICMAN-CSIC), Puerto Real, Cádiz E-11510, Spain
| | - Marco Antonio Campinho
- Centre of Marine Sciences (CCMar), Universidade do Algarve, Campus de Gambelas, Faro 8005-139, Portugal
| | - Juan Miguel Mancera
- Departamento de Biología, Facultad de Ciencias del Mar y Ambientales, Universidad de Cádiz, Puerto Real, Cádiz E-11510, Spain
| | - Gonzalo Martínez-Rodríguez
- Instituto de Ciencias Marinas de Andalucía, Consejo Superior Investigaciones Científicas (ICMAN-CSIC), Puerto Real, Cádiz E-11510, Spain
| | - Juan Fuentes
- Centre of Marine Sciences (CCMar), Universidade do Algarve, Campus de Gambelas, Faro 8005-139, Portugal
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Martos-Sitcha JA, Fuentes J, Mancera JM, Martínez-Rodríguez G. Variations in the expression of vasotocin and isotocin receptor genes in the gilthead sea bream Sparus aurata during different osmotic challenges. Gen Comp Endocrinol 2014; 197:5-17. [PMID: 24332959 DOI: 10.1016/j.ygcen.2013.11.026] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Revised: 11/21/2013] [Accepted: 11/27/2013] [Indexed: 11/24/2022]
Abstract
The dynamic changes in mRNA expression levels for vasotocin (AVT) and isotocin (IT) receptor gene levels were assessed in a time-course response study in immature male specimens of the gilthead sea bream (Sparus aurata) submitted to hyper- (55‰ salinity) and hypo-osmotic (5‰ salinity) challenges. Two different cDNAs for the AVT receptor and one for the IT receptor (V1a2-type and V2-type AVTR, and ITR, respectively) were cloned by screening an S. aurata brain cDNA library. Genes for these receptors were expressed differentially and is nearly ubiquitously in 26 of the examined tissues. In the gills, both environmental salinity challenges up-regulated AVTR V1a2-type gene expression concomitantly with mRNA expression protein activity of Na(+), K(+)-ATPase gene expression and protein, whereas the AVTR V2-type and cystic fibrosis transmembrane conductance regulator (CFTR) mRNA levels were associated with mRNAs environmental salinity, indicating a possible connection between AVTRs and these transporters. In kidney, AVTR V1a2-type gene expression peaked rapidly and lasted only a short time (12-24h) in response to both osmotic challenges. In contrast, AVTR V2-type mRNA levels were enhanced in specimens exposed to hyperosmotic conditions, whereas they decreased under hypoosmotic environments, suggesting an antidiuretic role related to the vasoconstriction function. In the hypothalamus, only the expression of the AVTR V2-type gene was enhanced at 7 and 14 days under both experimental conditions. In the liver, both AVTRs had increased mRNA levels, with the upregulation of their AVTR V2-type gene increasing faster than the V1a2-type. The ITR gene was not sensitive to variations of external salinity in any of the analyzed tissues. Our results demonstrate the involvement of the vasotocinergic, but not the isotocinergic, pathway as well as the hypothalamic function, in the adjustments of both osmoregulatory and metabolic processes after osmotic challenges.
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Affiliation(s)
- J A Martos-Sitcha
- Department of Biology, Faculty of Marine and Environmental Sciences, University of Cádiz, 11510 Puerto Real, Cádiz, Spain; Centre of Marine Sciences (CCMar), CIMAR - Laboratório Associado, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal; Instituto de Ciencias Marinas de Andalucía, Consejo Superior de Investigaciones Científicas, 11510 Puerto Real, Cádiz, Spain.
| | - J Fuentes
- Centre of Marine Sciences (CCMar), CIMAR - Laboratório Associado, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal
| | - J M Mancera
- Department of Biology, Faculty of Marine and Environmental Sciences, University of Cádiz, 11510 Puerto Real, Cádiz, Spain
| | - G Martínez-Rodríguez
- Instituto de Ciencias Marinas de Andalucía, Consejo Superior de Investigaciones Científicas, 11510 Puerto Real, Cádiz, Spain
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Martos-Sitcha JA, Wunderink YS, Gozdowska M, Kulczykowska E, Mancera JM, Martínez-Rodríguez G. Vasotocinergic and isotocinergic systems in the gilthead sea bream (Sparus aurata): an osmoregulatory story. Comp Biochem Physiol A Mol Integr Physiol 2013; 166:571-81. [PMID: 24021911 DOI: 10.1016/j.cbpa.2013.09.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Revised: 08/29/2013] [Accepted: 09/03/2013] [Indexed: 10/26/2022]
Abstract
To investigate the physiological roles of arginine vasotocin (AVT) and isotocin (IT) in osmoregulatory process in gilthead sea bream (Sparus aurata), a time course study (0, 12h, and 1, 3, 7 and 14 days) has been performed in specimens submitted to hypoosmotic (from 40‰ salinity to 5‰ salinity) or hyperosmotic (from 40‰ salinity to 55‰ salinity) challenges. Plasma and liver osmoregulatory and metabolic parameters, as well as AVT and IT pituitary contents were determined concomitantly with hypothalamic pro-vasotocin (pro-VT) and pro-isotocin (pro-IT) mRNA expression levels. Previously, sequences coding for pro-VT and pro-IT cDNAs were cloned. Two osmoregulatory periods related to plasma osmolality and metabolic parameter variations could be distinguished: i) an adaptative period, from 12h to 3 days after transfer, and ii) a chronic regulatory period, starting at day 3 after transfer. Higher values in hypothalamic pro-VT and pro-IT mRNA expression as well as in pituitary AVT and IT storage levels in both hypo- and/or hyper-osmotic transfers have been distinguished. These increase correlated with changes in plasma cortisol levels, suggesting an interaction between this hormone and pro-VT expression. Furthermore, pro-IT expression enhancement also suggests a role of the isotocinergic system as a modulator in the acute stress response induced by hyper-osmotic challenge in S. aurata.
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Affiliation(s)
- J A Martos-Sitcha
- Department of Biology, Faculty of Marine and Environmental Sciences, University of Cádiz, 11510 Puerto Real, Cádiz, Spain; Instituto de Ciencias Marinas de Andalucía (ICMAN), Consejo Superior de Investigaciones Científicas (CSIC), 11510 Puerto Real, Cádiz, Spain.
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Kawauchi H, Sower SA, Moriyama S. Chapter 5 The Neuroendocrine Regulation of Prolactin and Somatolactin Secretion in Fish. FISH PHYSIOLOGY 2009. [DOI: 10.1016/s1546-5098(09)28005-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Gao X, Brailoiu GC, Brailoiu E, Dun SL, Yang J, Chang JK, Dun NJ. Copeptin immunoreactivity and calcium mobilisation in hypothalamic neurones of the rat. J Neuroendocrinol 2008; 20:1242-51. [PMID: 18752653 DOI: 10.1111/j.1365-2826.2008.01782.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Copeptin is cleaved from the C-terminus of vasopressin (VP) prohormone. Immunohistochemical studies have revealed intense copeptin-immunoreactivity (irCOPT) in neurones of the rat hypothalamic nuclei, including paraventricular, supraoptic, suprachiasmatic, periventricular, and accessory secretory. Varicose cell processes emanated from irCOPT neurones, some of which projected caudally and traversed the internal layer of the median eminence, and terminated in the posterior pituitary. Double-labelling hypothalamic sections with copeptin antiserum and VP or oxytocin antiserum revealed an extensive overlapping of irCOPT and irVP neurones. The biological activity of human synthetic nonglycosylated copeptin or VP was evaluated in vivo and in vitro. Copeptin (1, 10, and 20 nmol/kg) injected i.v. caused no significant changes in the mean arterial pressure (MAP) and heart rate of urethane-anaesthetised rats. VP (0.1 nmol/kg) increased MAP, which was accompanied by a small decrease of the heart rate. The ratiometric fluorescence method was employed to assess changes in intracellular Ca2+ concentrations [Ca2+](i) which served as an index of the biological activity of peptides. VP (1 microM) markedly increased [Ca2+](i) of rat hypothalamic neurones or vascular smooth muscle cells, whereas copeptin (100 nm to 1 microM) caused a low amplitude, sustained increase of [Ca2+](i) in a population of hypothalamic neurones, but not in any of the vascular smooth muscle cells tested. The results obtained demonstrate that copeptin is expressed in VP neurones and that the peptide in the concentrations tested, although causing little or no detectable changes of blood pressure and heart rate in anaesthetised rats nor changes in [Ca2+](i) of cultured aortic smooth muscle cells, increases [Ca2+](i) in a small population (< 2%) of hypothalamic neurones tested, indicating that copeptin is biologically active in mammalian neurones.
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Affiliation(s)
- X Gao
- Department of Pharmacology, Temple University School of Medicine, Philadelphia, PA 19140, USA
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Gwee PC, Amemiya CT, Brenner S, Venkatesh B. Sequence and organization of coelacanth neurohypophysial hormone genes: evolutionary history of the vertebrate neurohypophysial hormone gene locus. BMC Evol Biol 2008; 8:93. [PMID: 18366747 PMCID: PMC2315648 DOI: 10.1186/1471-2148-8-93] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2008] [Accepted: 03/26/2008] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND The mammalian neurohypophysial hormones, vasopressin and oxytocin are involved in osmoregulation and uterine smooth muscle contraction respectively. All jawed vertebrates contain at least one homolog each of vasopressin and oxytocin whereas jawless vertebrates contain a single neurohypophysial hormone called vasotocin. The vasopressin homolog in non-mammalian vertebrates is vasotocin; and the oxytocin homolog is mesotocin in non-eutherian tetrapods, mesotocin and [Phe2]mesotocin in lungfishes, and isotocin in ray-finned fishes. The genes encoding vasopressin and oxytocin genes are closely linked in the human and rodent genomes in a tail-to-tail orientation. In contrast, their pufferfish homologs (vasotocin and isotocin) are located on the same strand of DNA with isotocin gene located upstream of vasotocin gene separated by five genes, suggesting that this locus has experienced rearrangements in either mammalian or ray-finned fish lineage, or in both lineages. The coelacanths occupy a unique phylogenetic position close to the divergence of the mammalian and ray-finned fish lineages. RESULTS We have sequenced a coelacanth (Latimeria menadoensis) BAC clone encompassing the neurohypophysial hormone genes and investigated the evolutionary history of the vertebrate neurohypophysial hormone gene locus within a comparative genomics framework. The coelacanth contains vasotocin and mesotocin genes like non-mammalian tetrapods. The coelacanth genes are present on the same strand of DNA with no intervening genes, with the vasotocin gene located upstream of the mesotocin gene. Nucleotide sequences of the second exons of the two genes are under purifying selection implying a regulatory function. We have also analyzed the neurohypophysial hormone gene locus in the genomes of opossum, chicken and Xenopus tropicalis. The opossum contains two tandem copies of vasopressin and mesotocin genes. The vasotocin and mesotocin genes in chicken and Xenopus, and the vasopressin and mesotocin genes in opossum are linked tail-to-head similar to their orthologs in coelacanth and unlike their homologs in human and rodents. CONCLUSION Our results indicate that the neurohypophysial hormone gene locus has experienced independent rearrangements in both placental mammals and teleost fishes. The coelacanth genome appears to be more stable than mammalian and teleost fish genomes. As such, it serves as a valuable outgroup for studying the evolution of mammalian and teleost fish genomes.
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Affiliation(s)
- Pai-Chung Gwee
- Institute of Molecular and Cell Biology, A*STAR (Agency for Science, Technology and Research), Biopolis, 138673, Singapore.
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