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Biagetti B, Puig-Domingo M. Age-Related Hormones Changes and Its Impact on Health Status and Lifespan. Aging Dis 2023; 14:605-620. [PMID: 37191429 PMCID: PMC10187696 DOI: 10.14336/ad.2022.1109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 11/09/2022] [Indexed: 05/17/2023] Open
Abstract
The increase in life expectancy is accompanied with an increased consultation of age-related pathologies including endocrine disorders. Two main areas are focusing the attention of medical and social research in older population: the diagnosis and care of this heterogeneous population, and the interventional measures potentially useful to mitigate age-related functional declines and to increase health and quality of lifespan. Thus, better understanding the physiopathology of aging and establishing accurate diagnostic and personalized approaches are a priority and currently an unmet need of the medical community. The endocrine system plays a major role in survival and lifespan through regulating vital processes such as energy consumption and optimizing the stress response among others. The aim of this paper is to review the physiological evolution of the main hormonal functions in aging and its clinical translation to improve our approach to the aging patient.
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Affiliation(s)
- Betina Biagetti
- Endocrinology & Nutrition Service, Vall d’Hebron University Hospital and Vall d'Hebron Research Institute (VHIR), Department of Medicine, Autonomous University of Barcelona, Barcelona, Spain.
| | - Manel Puig-Domingo
- Endocrinology & Nutrition Service, Germans Trias Hospital and Research Institute, Badalona, Department of Medicine, Autonomous University of Barcelona, Badalona, Spain.
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Carving the senescent phenotype by the chemical reactivity of catecholamines: An integrative review. Ageing Res Rev 2022; 75:101570. [PMID: 35051644 DOI: 10.1016/j.arr.2022.101570] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 01/11/2022] [Accepted: 01/15/2022] [Indexed: 11/21/2022]
Abstract
Macromolecules damaged by covalent modifications produced by chemically reactive metabolites accumulate in the slowly renewable components of living bodies and compromise their functions. Among such metabolites, catecholamines (CA) are unique, compared with the ubiquitous oxygen, ROS, glucose and methylglyoxal, in that their high chemical reactivity is confined to a limited set of cell types, including the dopaminergic and noradrenergic neurons and their direct targets, which suffer from CA propensities for autoxidation yielding toxic quinones, and for Pictet-Spengler reactions with carbonyl-containing compounds, which yield mitochondrial toxins. The functions progressively compromised because of that include motor performance, cognition, reward-driven behaviors, emotional tuning, and the neuroendocrine control of reproduction. The phenotypic manifestations of the resulting disorders culminate in such conditions as Parkinson's and Alzheimer's diseases, hypertension, sarcopenia, and menopause. The reasons to suspect that CA play some special role in aging accumulated since early 1970-ies. Published reviews address the role of CA hazardousness in the development of specific aging-associated diseases. The present integrative review explores how the bizarre discrepancy between CA hazardousness and biological importance could have emerged in evolution, how much does the chemical reactivity of CA contribute to the senescent phenotype in mammals, and what can be done with it.
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Saccon TD, Schneider A, Marinho CG, Nunes ADC, Noureddine S, Dhahbi J, Nunez Lopez YO, LeMunyan G, Salvatori R, Oliveira CRP, Oliveira‐Santos AA, Musi N, Bartke A, Aguiar‐Oliveira MH, Masternak MM. Circulating microRNA profile in humans and mice with congenital GH deficiency. Aging Cell 2021; 20:e13420. [PMID: 34118183 PMCID: PMC8282278 DOI: 10.1111/acel.13420] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 05/10/2021] [Accepted: 05/26/2021] [Indexed: 12/13/2022] Open
Abstract
Reduced inflammation, increased insulin sensitivity, and protection against cancer are shared between humans and mice with GH/IGF1 deficiency. Beyond hormone levels, miRNAs are important regulators of metabolic changes associated with healthy aging. We hypothesized that GH deficiency in humans alters the abundance of circulating miRNAs and that a subset of those miRNAs may overlap with those found in GH-deficient mice. In this study, subjects with untreated congenital isolated GH deficiency (IGHD; n = 23) and control subjects matched by age and sex (n = 23) were recruited and serum was collected for miRNA sequencing. Serum miRNAs from young (6 month) and old (22 month) Ames dwarf (df/df) mice with GH deficiency and their WT littermates (n = 5/age/genotype group) were used for comparison. We observed 14 miRNAs regulated with a genotype by age effect and 19 miRNAs regulated with a genotype effect independent of age in serum of IGHD subjects. These regulated miRNAs are known for targeting pathways associated with longevity such as mTOR, insulin signaling, and FoxO. The aging function was overrepresented in IGHD individuals, mediated by hsa-miR-31, hsa-miR-146b, hsa-miR-30e, hsa-miR-100, hsa-miR-181b-2, hsa-miR-195, and hsa-miR-181b-1, which target the FoxO and mTOR pathways. Intriguingly, miR-181b-5p, miR-361-3p, miR-144-3p, and miR-155-5p were commonly regulated in the serum of humans and GH-deficient mice. In vitro assays confirmed target genes for the main up-regulated miRNAs, suggesting miRNAs regulated in IGHD individuals can regulate the expression of age-related genes. These findings indicate that systemic miRNAs regulated in IGHD individuals target pathways involved in aging in both humans and mice.
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Affiliation(s)
- Tatiana D. Saccon
- Centro de Desenvolvimento Tecnológico Universidade Federal de Pelotas Pelotas Brazil
- Burnett School of Biomedical Sciences College of Medicine University of Central Florida Orlando FL USA
| | - Augusto Schneider
- Faculdade de Nutrição Universidade Federal de Pelotas Pelotas Brazil
| | - Cindi G. Marinho
- Division of Endocrinology Health Sciences Graduate Program Federal University of Sergipe Aracaju Brazil
| | - Allancer D. C. Nunes
- Burnett School of Biomedical Sciences College of Medicine University of Central Florida Orlando FL USA
| | - Sarah Noureddine
- Burnett School of Biomedical Sciences College of Medicine University of Central Florida Orlando FL USA
| | - Joseph Dhahbi
- Department of Medical Education School of Medicine California University of Science & Medicine San Bernardino CA USA
| | - Yury O. Nunez Lopez
- Advent Health Translational Research Institute for Metabolism and Diabetes Orlando FL USA
| | - Gage LeMunyan
- Department of Medical Education School of Medicine California University of Science & Medicine San Bernardino CA USA
| | - Roberto Salvatori
- Division of Endocrinology, Diabetes and Metabolism Department of Medicine The Johns Hopkins University School of Medicine Baltimore MD USA
| | - Carla R. P. Oliveira
- Division of Endocrinology Health Sciences Graduate Program Federal University of Sergipe Aracaju Brazil
| | - Alécia A. Oliveira‐Santos
- Division of Endocrinology Health Sciences Graduate Program Federal University of Sergipe Aracaju Brazil
| | - Nicolas Musi
- Barshop Institute for Longevity and Aging Studies Center for Healthy Aging University of Texas Health Sciences Center at San Antonio and South Texas Veterans Health Care System San Antonio TX USA
- San Antonio Geriatric Research Education and Clinical Center South Texas Veterans Health Care System San Antonio TX USA
| | - Andrzej Bartke
- Department of Internal Medicine Southern Illinois University School of Medicine Springfield IL USA
| | - Manuel H. Aguiar‐Oliveira
- Division of Endocrinology Health Sciences Graduate Program Federal University of Sergipe Aracaju Brazil
| | - Michal M. Masternak
- Burnett School of Biomedical Sciences College of Medicine University of Central Florida Orlando FL USA
- Department of Head and Neck Surgery Poznan University of Medical Sciences Poznan Poland
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Stangerup I, Hannibal J. Localization of Vasoactive Intestinal Polypeptide Receptor 1 (VPAC1) in Hypothalamic Neuroendocrine Oxytocin Neurons; A Potential Role in Circadian Prolactin Secretion. Front Neuroanat 2020; 14:579466. [PMID: 33192343 PMCID: PMC7658414 DOI: 10.3389/fnana.2020.579466] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 09/22/2020] [Indexed: 11/13/2022] Open
Abstract
Prolactin (PRL) is a versatile hormone and serves a broad variety of physiological functions besides lactation. The release of PRL from lactotrophs in the pituitary has in rodents been shown to be released with a circadian pattern depending on the physiological state of the animal. The circadian release of PRL seems to be complex involving tonic inhibition by dopamine (DA) neurons on lactotrophs and one or even several releasing factors. Because of the circadian releasing pattern of PRL, neurons in the suprachiasmatic nucleus (SCN), "the brain clock," and especially the neurons expressing neuropeptide vasoactive intestinal polypeptide (VIP), have been suggested to be involved in the circadian regulation of PRL. In the present study, we used fluorescence immunohistochemistry, in situ hybridization histochemistry, confocal microscopy, three-dimensional reconstruction, and highly specific antibodies to visualize the occurrence of VIP receptors 1 and 2 (VPAC1 and VPAC2) in mouse brain hypothalamic sections stained in combination with VIP, oxytocin (OXT), arginine vasopressin (AVP), and DA (tyrosine hydroxylase, TH). We demonstrated that VIP fibers most likely originating from the ventral part of the SCN project to OXT neurons in the magnocellular part of the paraventricular nucleus (PVN). In the PVN, VIP fibers were found in close apposition to OXT neuron exclusively expressing the VPAC1 receptor. Furthermore, we demonstrate that neither OXT neurons nor TH or AVP neurons were expressing the VPAC2 receptor. VPAC1 receptor expression was also found on blood vessels but not in neurons expressing AVP or TH. These findings suggest that VIP signaling from the SCN does not directly target DA neurons involved in PRL secretion. Furthermore, the findings support the notion that VIP from neurons in the SCN could regulate circadian release of OXT in the posterior pituitary or modulate OXT neurons as a releasing factor involved in the circadian regulation of PRL from pituitary lactotrophs.
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Affiliation(s)
- Ida Stangerup
- Department of Clinical Biochemistry, Faculty of Health Sciences, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
| | - Jens Hannibal
- Department of Clinical Biochemistry, Faculty of Health Sciences, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
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Arnold E, Thébault S, Aroña RM, Martínez de la Escalera G, Clapp C. Prolactin mitigates deficiencies of retinal function associated with aging. Neurobiol Aging 2019; 85:38-48. [PMID: 31698287 DOI: 10.1016/j.neurobiolaging.2019.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 10/03/2019] [Accepted: 10/04/2019] [Indexed: 01/17/2023]
Abstract
Aging causes the progressive degeneration of retinal cells leading to the eventual loss of vision. The hormone prolactin (PRL) is a neurotrophic factor able to compensate for photoreceptor cell death and electroretinogram deficits induced by light retinal damage. Here, we used adult 4-month old and aged 20-month old pigmented mice, null or not for the PRL receptor to explore whether PRL provides trophic support against age-related retinal dysfunction. Retinal functionality, apoptosis, glia activation, and neurotrophin expression were assessed by electroretinogram, TUNEL, glial fibrillary acidic protein and ionized calcium binding adaptor molecule 1 immunohistochemistry, and real-time PCR, respectively. Lack of PRL signaling in aged mice, but not in adult mice, correlated with photosensitive retinal dysfunction, increased photoreceptor apoptosis, differential expression of proapoptotic mediators, and microglia activation. We conclude that PRL is required for maintaining retinal functionality in both female and male mice during aging and has potential therapeutic value against age-related retinal disorders.
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Affiliation(s)
- Edith Arnold
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Campus UNAM-Juriquilla, Querétaro, México; CONACYT-Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Campus UNAM-Juriquilla, Querétaro, México
| | - Stéphanie Thébault
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Campus UNAM-Juriquilla, Querétaro, México
| | - Rodrigo M Aroña
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Campus UNAM-Juriquilla, Querétaro, México
| | | | - Carmen Clapp
- Instituto de Neurobiología, Universidad Nacional Autónoma de México (UNAM), Campus UNAM-Juriquilla, Querétaro, México.
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Phonchai R, Phermthai T, Kitiyanant N, Suwanjang W, Kotchabhakdi N, Chetsawang B. Potential effects and molecular mechanisms of melatonin on the dopaminergic neuronal differentiation of human amniotic fluid mesenchymal stem cells. Neurochem Int 2018; 124:82-93. [PMID: 30593827 DOI: 10.1016/j.neuint.2018.12.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 12/07/2018] [Accepted: 12/21/2018] [Indexed: 11/30/2022]
Abstract
Melatonin, a highly lipophilic molecule secreted by the pineal gland in the brain, plays a role in various biological functions. Previous studies reported that melatonin exerts its effect on mesenchymal stem cell (MSC) survival and differentiation into osteogenic- and adipogenic-lineage. However, the effect of melatonin in neurogenic differentiation in amniotic fluid (AF)-MSCs remains to be explored, thus we investigated the potential role of melatonin on dopaminergic neuron differentiation in AF-MSCs. The results showed that various concentrations of melatonin did not affect cell viability and proliferative effects of AF-MSCs. Increases in the levels of neuronal protein marker (βIII-tubulin) and dopaminergic neuronal markers (tyrosine hydroxylase, TH and NURR1), but decrease in the level of glial fibrillary acidic protein (GFAP), were observed in melatonin-treated AF-MSCs. Melatonin induced alteration in differential expression patterns of mesenchymal stem cell antigens by reducing CD29, CD45, CD73, CD90 and CD105, but no changing CD34 expressing cells. AF-MSCs were sequentially induced in neurobasal medium containing standard inducing cocktails (ST: bFGF, SHH, FGF8, BDNF), 1 μM melatonin, or a combination of ST and melatonin. The levels of TUJ1, TH, MAP2, NURR1 and dopamine transporter (DAT) were significantly increased in all treated groups when compared with control-untreated cells. Pretreated AF-MSCs with non-selective MT1/MT2 receptors antagonist, luzindole and selective MT2 receptor antagonist, 4-P-PDOT diminished melatonin-induced increase in dopaminergic neuronal markers and phosphorylated ERK but did not diminish increase in phosphorylated CaMKII by melatonin. Pretreatment with mitogen-activated protein kinase (MEK) inhibitor, PD98059 and CaMKII inhibitor, KN-93 were able to abolish increase in the levels of dopaminergic markers in melatonin-treated AF-MSCs. These findings suggest that melatonin promotes dopaminergic neuronal differentiation of AF-MSCs possibly via the induction in ERK and CaMKII pathways through melatonin receptor-dependent and -independent mechanisms, respectively.
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Affiliation(s)
- Ruchee Phonchai
- Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand
| | - Tassanee Phermthai
- Stem Cell Research and Development Unit, Department of Obstetrics and Gynecology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Narisorn Kitiyanant
- Stem Cell Research Group, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand
| | - Wilasinee Suwanjang
- Center for Research and Innovation, Faculty of Medical Technology, Mahidol University, Salaya, Nakhon Pathom, Thailand
| | - Naiphinich Kotchabhakdi
- Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand
| | - Banthit Chetsawang
- Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, Thailand.
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Arutyunyan AV, Korenevskii AV. Age-related impairment of hypothalamic regulation of the reproductive cycle and its correction. ADVANCES IN GERONTOLOGY 2014. [DOI: 10.1134/s2079057014040043] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Kumar B, Kuhad A, Chopra K. Neuropsychopharmacological effect of sesamol in unpredictable chronic mild stress model of depression: behavioral and biochemical evidences. Psychopharmacology (Berl) 2011; 214:819-28. [PMID: 21103863 DOI: 10.1007/s00213-010-2094-2] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Accepted: 11/01/2010] [Indexed: 11/24/2022]
Abstract
RATIONALE A complex relationship exists among stressful situations, body's reaction to stress, and the onset of clinical depression. Chronic unpredictable stressors can produce a situation similar to clinical depression, and such animal models can be used for the preclinical evaluation of antidepressants. Many findings have shown that the levels of proinflammatory cytokines (e.g., TNF-α) and oxidative stress (increased lipid peroxidation, decreased glutathione levels, and endogenous antioxidant enzyme activities) are increased in patients with depression. Sesamol, a phenolic derivative with a methylenedioxy group, is a potent inhibitor of cytokine production as well as an antioxidant. OBJECTIVES The present study was designed to investigate the effect of sesamol on unpredictable chronic stress-induced behavioral and biochemical alterations in mice. METHODS Animals were subjected to different stress paradigms daily for a period of 21 days to induce depressive-like behavior. The sucrose preference, immobility period, locomotor activity, memory acquisition, and retention were evaluated. RESULTS Chronic treatment with sesamol significantly reversed the unpredictable chronic stress-induced behavioral (increased immobility period, reduced sucrose preference), biochemical (increased lipid peroxidation and nitrite levels; decreased glutathione levels, superoxide dismutase and catalase activities), and inflammation surge (serum TNF-α) in stressed mice. CONCLUSION The study revealed that sesamol exerted antidepressant-like effects in behavioral despair paradigm in chronically stressed mice, specifically by modulating central oxidative-nitrosative stress and inflammation.
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Affiliation(s)
- Baldeep Kumar
- Pharmacology Research Laboratory, University Institute of Pharmaceutical Sciences, UGC Centre of Advanced Study, Panjab University, Chandigarh, 160014, India
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Caride A, Fernández-Pérez B, Cabaleiro T, Tarasco M, Esquifino AI, Lafuente A. Cadmium chronotoxicity at pituitary level: effects on plasma ACTH, GH, and TSH daily pattern. J Physiol Biochem 2010; 66:213-20. [PMID: 20652474 DOI: 10.1007/s13105-010-0027-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2009] [Accepted: 06/03/2010] [Indexed: 01/07/2023]
Abstract
Cadmium is an endocrine disruptor that has been shown to induce chronotoxic effects. The present study was designed to evaluate the possible cadmium effects on the daily secretory pattern of adrenocorticotropin hormone (ACTH), growth hormone (GH), and thyroid-stimulating hormone (TSH) in adult male Sprague-Dawley rats. For this purpose, animals were treated with cadmium at two different doses [25 and 50 mg/l cadmium chloride (CdCl(2))] in the drinking water for 30 days. Control age-matched rats received cadmium-free water. After the treatment, rats were killed at six different time intervals throughout a 24-h cycle. Cadmium exposure modified the 24-h pattern of plasma ACTH and GH levels, as the peak of ACTH content between 12:00 and 16:00 h in controls appeared at 12:00 h in the group treated with the lowest dose used, while it appeared between 16:00 and 20:00 h in rats exposed to 50 mg/l CdCl(2). In addition, the peak of GH content found at 04:00 h in controls moved to 16:00 h in rats exposed to 25 mg/l CdCl(2), and the highest dose used abolished 24-h changes of GH secretion. The metal treatment did not modify ACTH secretory pattern. Exposure to cadmium also increased ACTH and TSH medium levels around the clock with both doses used. These results suggest that cadmium modifies ACTH and TSH medium levels around the clock, as well as disrupted ACTH and GH secretory pattern, thus confirming the metal chronotoxicity at pituitary level.
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Affiliation(s)
- Ana Caride
- Laboratorio de Toxicología, Facultad de Ciencias, Universidad de Vigo, Campus de Orense, Las Lagunas, Orense, Spain.
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Chen SC, Lu G, Chan CY, Chen Y, Wang H, Yew DTW, Feng ZT, Kung HF. Microarray Profile of Brain Aging-Related Genes in the Frontal Cortex of SAMP8. J Mol Neurosci 2009; 41:12-6. [DOI: 10.1007/s12031-009-9215-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Accepted: 06/30/2009] [Indexed: 12/23/2022]
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11
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Daily pattern of pituitary glutamine, glutamate, and aspartate content disrupted by cadmium exposure. Amino Acids 2009; 38:1165-72. [PMID: 19636671 DOI: 10.1007/s00726-009-0327-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2009] [Accepted: 07/13/2009] [Indexed: 10/20/2022]
Abstract
Cadmium is a neurotoxic heavy metal and is considered endocrine disruptor. In this work, we investigate the effects of cadmium on the 24 h changes of aspartate, glutamate, and glutamine content in the pituitary. Adult male Sprague-Dawley rats were treated with 25 or 50 mg/l of cadmium chloride (CdCl(2)) in the drinking water for 30 days. Metal exposure with the lowest dose induced the disappearance of the nocturnal peak of anterior pituitary amino acid content, and the appearance of a peak of glutamine concentration during the resting phase of the photoperiod. After exposure to 50 mg/l of CdCl(2), the peaks of anterior pituitary amino acid content at 12:00 and 00:00 h disappeared, and two minimal values at these same hours and a peak at 08:00 h appeared. In the posterior pituitary, cadmium treatment with the lowest dose induced the appearance of a peak of aspartate and glutamate concentration at 12:00 h, and the disappearance of the peak of glutamine content at 16:00 h. After exposure to 50 mg/l of CdCl(2) aspartate and glutamate daily pattern presented two maximal values between 00:00 and 04:00 h, and the metal abolished glutamine daily pattern. These results suggest that cadmium disrupted aspartate, glutamate, and glutamine daily pattern in the pituitary.
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Maronpot RR, Zeiger E, McConnell EE, Kolenda-Roberts H, Wall H, Friedman MA. Induction of tunica vaginalis mesotheliomas in rats by xenobiotics. Crit Rev Toxicol 2009; 39:512-37. [DOI: 10.1080/10408440902969430] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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13
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Caride A, Fernández-Pérez B, Cabaleiro T, Esquifino A, Lafuente A. Cadmium exposure disrupts GABA and taurine regulation of prolactin secretion in adult male rats. Toxicol Lett 2009; 185:175-9. [DOI: 10.1016/j.toxlet.2008.12.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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14
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Rollo CD. Dopamine and Aging: Intersecting Facets. Neurochem Res 2008; 34:601-29. [DOI: 10.1007/s11064-008-9858-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2008] [Accepted: 07/03/2008] [Indexed: 10/21/2022]
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15
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Effects of Every-Other-Day Feeding on Prolactin Regulatory Mechanism in Transgenic Human Growth Hormone Mice. Exp Biol Med (Maywood) 2008; 233:434-8. [DOI: 10.3181/0708-rm-217] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Transgenic mice overexpressing human growth hormone (hGH) exhibit accelerated aging with functional hyperprolactinemia and greatly depressed endogenous prolactin. Calorie restriction (CR) is widely recognized as the most effective experimental intervention to delay aging. The aim of the present work was to analyze the effects of lifelong overexpression of hGH on prolactin-gene expression as well as the dopamine production at the pituitary level and discern whether this mechanism changes as a function of feeding patterns. Ten-month-old mice fed every other day (EOD) were killed after one day of fasting. The results confirmed typical phenotypic features of these transgenic mice: an increase in body weight, very high hGH plasma concentrations, and hyperinsulinemia. There was a marked inhibition of the expression of the prolactin gene, together with an increased tyrosine hydroxylase (TH) and the long isoform of dopamine receptor type 2 (D2LR) gene expression at the pituitary level. These parameters were not affected by the EOD feeding pattern. These data may suggest an autocrine or paracrine effect of dopamine at the hypophyseal level on prolactin secretion that is independent of the feeding pattern.
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Horner KC, Cazals Y, Guieu R, Lenoir M, Sauze N. Experimental estrogen-induced hyperprolactinemia results in bone-related hearing loss in the guinea pig. Am J Physiol Endocrinol Metab 2007; 293:E1224-32. [PMID: 17711987 DOI: 10.1152/ajpendo.00279.2007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Our group (Horner KC, Guieu R, Magnan J, Chays A, Cazals Y. Neuropsychopharmacology 26: 135-138, 2002) has earlier described hyperprolactinemia in some patients presenting inner ear dysfunction. However, in that study, it was not possible to determine whether hyperprolactinemia was a cause or an effect of the symptoms. To investigate the effect of hyperprolactinemia on inner ear function, we first developed a model of hyperprolactinemia in estrogen-primed Fischer 344 rats and then performed functional studies on pigmented guinea pigs. Hyperprolactinemia induced, after 2 mo, a hearing loss of approximately 30-40 dB across all frequencies, as indicated by the compound action potential audiogram. During the 3rd mo, the hearing loss continued to deteriorate. The threshold shifts were more substantial in males than in females. Observations under a dissection microscope revealed bone dysmorphology of the bulla and the cochlea. Light microscopy observations of cryostat sections confirmed bone-related pathology of the bony cochlear bulla and the cochlear wall and revealed morphopathology of the stria vascularis and spiral ligament. Scanning electron microscopy revealed loss of hair cells and stereocilia damage, in particular in the upper three cochlear turns and the two outermost hair cell rows. The data provide the first evidence of otic capsule and hair cell pathology associated with estrogen-induced prolonged hyperprolactinemia and suggest that conditions such as pregnancy, anti-psychotic drug treatment, aging, and/or stress might lead to similar ear dysfunctions.
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Affiliation(s)
- Kathleen C Horner
- CNRS UMR 6153-1147 INRA, Université Paul Cézanne, Faculté des Sciences et Techniques, Campus St Jérôme, Cases 351 352, Ave Escadrille Normandie Niémen, 13397, Marseille Cedex 20, France.
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Esquifino AI, Cano P, Jiménez-Ortega V, Fernández-Mateos P, Cardinali DP. Neuroendocrine-immune correlates of circadian physiology: studies in experimental models of arthritis, ethanol feeding, aging, social isolation, and calorie restriction. Endocrine 2007; 32:1-19. [PMID: 17992597 DOI: 10.1007/s12020-007-9009-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Revised: 09/11/2007] [Accepted: 09/11/2007] [Indexed: 10/22/2022]
Abstract
Virtually all neuroendocrine and immunological variables investigated in animals and humans display biological periodicity. Circadian rhythmicity is revealed for every hormone in circulation as well as for circulating immune cells, lymphocyte metabolism and transformability, cytokines, receptors, and adhesion molecules. Clock genes, notably the three Period (Per1/Per2/Per3) genes and two Cryptochrome (Cry1/Cry2) genes, are present in immune and endocrine cells and are expressed in a circadian manner in human cells. This review discusses the circadian disruption of hormone release and immune-related mechanisms in several animal models in which circulating cytokines are modified including rat adjuvant arthritis, social isolation in rats and rabbits and alcoholism, the aging process and calorie restriction in rats. In every case the experimental manipulation used perturbed the temporal organization by affecting the shape and amplitude of a rhythm or by modifying the intrinsic oscillatory mechanism itself.
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Affiliation(s)
- Ana I Esquifino
- Departamento de Bioquimica y Biologia Molecular III, Facultad de Medicina, Universidad Complutense, 28040, Madrid, Spain.
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Gonzales PH, Rhoden CR, Luz C, Corrêa G, Barbosa-Coutinho LM, Oliveira MC. Male gonadal function, prolactin secretion and lactotroph population in an experimental model of cirrhosis. ACTA ACUST UNITED AC 2007; 40:1383-8. [PMID: 17713659 DOI: 10.1590/s0100-879x2006005000150] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2006] [Accepted: 06/12/2007] [Indexed: 11/22/2022]
Abstract
Liver cirrhosis, a highly prevalent chronic disease, is frequently associated with endocrine dysfunctions, notably in the gonadal axis. We evaluated lactotroph population by immunohistochemistry, gonadotropins and prolactin by immunoradiometric assay and testosterone and estradiol by radioimmunoassay in adult male Wistar rats with cirrhosis induced by carbon tetrachloride. No significant difference in mean +/- SEM percentages of lactotrophs was found between cirrhotic animals and controls (N = 12, mean 18.95 +/- 1.29%). Although there was no significant difference between groups in mean serum levels of prolactin (control: 19.2 +/- 4 ng/mL), luteinizing hormone (control: 1.58 +/- 0.43 ng/mL), follicle-stimulating hormone (control: 19.11 +/- 2.28 ng/mL), estradiol (control: 14.65 +/- 3.22 pg/mL), and total testosterone (control: 138.41 +/- 20.07 ng/dL), 5 of the cirrhotic animals presented a hormonal profile consistent with hypogonadism, all of them pointing to a central origin of this dysfunction. Four of these animals presented high levels of estradiol and/or prolactin, with a significant correlation between these two hormones in both groups (r = 0.54; P = 0.013). It was possible to detect the presence of central hypogonadism in this model of cirrhotic animals. The hyperestrogenemia and hyperprolactinemia found in some hypogonadal animals suggest a role in the genesis of hypogonadism, and in the present study they were not associated with lactotroph hyperplasia.
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Affiliation(s)
- P H Gonzales
- Departamento de Endocrinologia, Fundação Faculdade Federal de Ciências Médicas de Porto Alegre, RS, Brasil
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Baranowska B, Wolinska-Witort E, Bik W, Baranowska-Bik A, Martynska L, Broczek K, Mossakowska M, Chmielowska M. Evaluation of neuroendocrine status in longevity. Neurobiol Aging 2007; 28:774-83. [PMID: 16698123 DOI: 10.1016/j.neurobiolaging.2006.03.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2005] [Revised: 03/13/2006] [Accepted: 03/23/2006] [Indexed: 01/01/2023]
Abstract
It is well known that physiological changes in the neuroendocrine system may be related to the process of aging. To assess neuroendocrine status in aging humans we studied a group of 155 women including 78 extremely old women (centenarians) aged 100-115 years, 21 early elderly women aged 64-67 years, 21 postmenopausal women aged 50-60 years and 35 younger women aged 20-50 years. Plasma NPY, leptin, glucose, insulin and lipid profiles were evaluated, and serum concentrations of pituitary, adrenal and thyroid hormones were measured. Our data revealed several differences in the neuroendocrine and metabolic status of centenarians, compared with other age groups, including the lowest serum concentrations of leptin, insulin and T3, and the highest values for prolactin. We failed to find any significant differences in TSH and cortisol levels. On the other hand, LH and FSH levels were comparable with those in the elderly and postmenopausal groups, but they were significantly higher than in younger subjects. GH concentrations in centenarians were lower than in younger women. NPY values were highest in the elderly group and lowest in young subjects. We conclude that the neuroendocrine status in centenarians is markedly different from that found in early elderly or young women.
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Affiliation(s)
- Boguslawa Baranowska
- Neuroendocrinology Department, Medical Centre of Postgraduate Education, Marymoncka 99, 01-813 Warsaw, Poland.
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Jiménez-Ortega V, Cardinali DP, Cano P, Fernández-Mateos P, Reyes-Toso C, Esquifino AI. Effect of ethanol on 24-h hormonal changes in prolactin release mechanisms in growing male rats. Endocrine 2006; 30:269-78. [PMID: 17526938 DOI: 10.1007/s12020-006-0004-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Revised: 10/23/2006] [Accepted: 11/29/2006] [Indexed: 01/25/2023]
Abstract
This study analyzes the effect of chronic ethanol feeding on 24-h variation of hypothalamic-pituitary mechanisms involved in prolactin regulation in growing male Wistar rats. Animals were maintained under a 12:12 h light/dark photoperiod (lights off at 2000 h), and they received a liquid diet for 4 wk, starting on d 35 of life. The ethanol-fed group received a similar diet to controls except that maltose was isocalorically replaced by ethanol. Ethanol replacement provided 36% of the total caloric content of the diet. Rats were killed at six time intervals every 4 h, beginning at 0900 h. Mean concentration of serum prolactin in ethanol-fed rats was 58.7% higher than in controls. Peak circulating prolactin levels occurred at the early phase of the activity span in both groups of rats, whereas a second peak was found late in the resting phase in ethanol-fed rats only. In control rats, median eminence dopamine (DA), serotonin (5-HT), gamma-aminobutyric acid (GABA), and taurine levels exhibited two maxima, the major one preceding prolactin release and a second one during the first part of the resting phase. Median eminence DA and 5-HT turnover (as measured by 3,4-dihydroxyphenylacetic acid, DOPAC/DA, and 5-hydroxyindoleacetic acid, 5-HIAA/5-HT ratio) showed a single maximum preceding prolactin, at 0100 h. Ethanol treatment did not affect median eminence DA or 5-HT levels but it decreased significantly their turnover rate. The midday peak in DA and 5-HT levels (at 1300 h) was abolished and the night peak (at 0100 h) became spread and blunted in the ethanol-fed rats. This was accompanied with the disappearance of the 0100 h peak in DA and 5-HT turnover and the occurrence of a peak in 5-HT turnover at 1700 h. Ethanol intake suppressed the night peak in median eminence GABA and taurine (at 0100 h) as well as the midday peak of GABA. Ethanol augmented pituitary levels of DOPAC and 5-HIAA. The results indicate that chronic ethanol administration affects the mechanisms that modulate the circadian variation of prolactin release in growing male rats.
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Affiliation(s)
- Vanesa Jiménez-Ortega
- Departamento de Bioquímica y Biología Molecular III, Facultad de Medicina, Universidad Complutense, 28040 Madrid, Spain
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Alvarez MP, Jiménez V, Cano P, Rebollar P, Cardinali DP, Esquifino AI. Circadian rhythms of prolactin secretion in neonatal female rabbits after acute separation from their mothers. Gen Comp Endocrinol 2006; 146:257-64. [PMID: 16426607 DOI: 10.1016/j.ygcen.2005.11.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2005] [Revised: 11/18/2005] [Accepted: 11/30/2005] [Indexed: 11/29/2022]
Abstract
Newborn rabbits (Oryctolagus cuniculus) are only nursed for 3-5 min every 24 h and show a circadian increase in activity in anticipation of nursing. The objective of this study was to determine, in neonatal female rabbits after acute separation from the doe for 48 h, the changes in 24-h rhythms of plasma prolactin and median eminence and anterior pituitary concentration of dopamine (DA) and serotonin (5HT). In addition, median eminence concentration of the excitatory amino acid transmitters glutamate (GLU) and aspartate (ASP) and of the inhibitory amino acid transmitters gamma-aminobutyric acid (GABA) and taurine (TAU) was measured. A significant 21% increase of circulating prolactin occurred in isolated pups. In controls pups, plasma prolactin levels showed two peaks, during the first half of the light phase and at the beginning of the scotophase, respectively. In the isolated pups, a phase advance of about 4 h occurred for the two prolactin peaks. Hemicircadian changes of median eminence DA were found in controls, whereas a single daily peak (at 17:00 h) was found in the separated pups. Plasma prolactin and median eminence DA correlated significantly and inversely in the control group only. Pituitary DA content exhibited a single peak in controls and a hemicircadian pattern in isolated pups. Plasma prolactin and pituitary DA correlated significantly in isolated pups only 00000. Pup isolation decreased median eminence 5HT levels, augmented pituitary 5HT levels and disrupted their 24 h rhythmicity. Circulating prolactin correlated inversely with median eminence 5HT and directly with adenohypophysial 5HT only in controls. Isolation of pups generally modified the 24 h pattern of median eminence excitatory and inhibitory amino acid content by causing a prominent decrease at the beginning of the light phase. The results indicate that circadian rhythmicity of prolactin secretory mechanisms in female rabbit pups is significantly affected by pup's isolation from the doe.
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Affiliation(s)
- M P Alvarez
- Departamento de Biología Celular, Facultad de Medicina, Universidad Complutense de Madrid, Spain
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Lafuente A, Cabaleiro T, Cano P, Esquifino AI. Toxic effects of methoxychlor on the episodic prolactin secretory pattern: possible mediated effects of nitric oxide production. J Circadian Rhythms 2006; 4:3. [PMID: 16515688 PMCID: PMC1450319 DOI: 10.1186/1740-3391-4-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2005] [Accepted: 03/03/2006] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND This work addresses the issue of whether methoxychlor (MTX) exposure may modify the ultradian secretion of prolactin through changes in the synthesis of nitric oxide (NO) induced by Nomega-nitro-L-arginine methyl ester (L-NAME) in the hypothalamic-pituitary axis. Associated changes in dopamine (DA) content in the anterior (AH), mediobasal (MBH) and posterior hypothalamus (PH) and median eminence (ME) were evaluated. METHODS Two groups of animals (MTX and MTX+L-NAME treated) received subcutaneous (sc) injections of MTX at a dose of 25 mg/kg/day for one month. The other two groups of animals (control and L-NAME treated) received sc vehicle injections (0.5 mL/day of sesame oil), during the same period of time to be used as controls. Forty hours before the day of the experiment, animals were anaesthetized with intrapritoneal injections of 2.5% tribromoethanol in saline and atrial cannulas were implanted through the external jugular vein. Plasma was continuously extracted in Hamilton syringes coupled to a peristaltic bomb in tubes containing phosphate-gelatine buffer (to increase viscosity). The plasma was obtained by decantation and kept every 7 minutes for the measurement of plasma prolactin levels through a specific radioimmnunoassay and DA concentration by high-pressure liquid chromatography (HPLC). RESULTS Prolactin release in animals from all experimental groups analyzed was episodic. Mean plasma prolactin levels during the bleeding period, and the absolute pulse amplitude were increased after MTX or Nomega-nitro-L-arginine methyl ester (L-NAME) administration. However MTX and L-NAME did not modify any other parameter studied with the exception of relative pulse amplitude in MTX treated rats. L-NAME administration to rats treated with the pesticide reduced mean plasma prolactin levels and the absolute amplitude of prolactin peaks. Peak duration, frequency and relative amplitude of prolactin peaks were not changed in the group of rats treated with MTX plus L-NAME as compared to either control or MTX treated rats. Whereas MTX decreased DA content in the ME and increased it in the AH, its content did not change in the MBH or PH, as compared to the values found in controls. Also, L-NAME administration decreased DA content in the ME as compared to controls. However, L- NAME administration to MTX exposed rats, markedly increased DA content in the ME as compared to either MTX treated or control rats. L-NAME administration increased DA content in the AH as compared to the values found in non-treated rats. However L-NAME administration to MTX exposed rats did not modify DA content as compared to either MTX treated or control rats. L-NAME administration did not modify DA content at the MBH nor in saline treated nor in MTX treated rats. However, the values of DA in the MBH in MTX plus L-NAME treated animals were statistically decreased as compared to L-NAME treated rats. In the PH, L-NAME administration increased DA content as compared to the values found in non-treated animals. L-NAME administration to MTX exposed rats also increased DA content as compared to either MTX treated or control rats. CONCLUSION The results suggest the existence of an interaction between MTX and L-NAME in the modulation of the ultradian prolactin secretion at the pituitary levels. The possibility of an indirect effect mediated by changes in DA content at the ME requires further examination.
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Affiliation(s)
- Anunciación Lafuente
- Laboratorio de Toxicología, Facultad de Ciencias, Universidad de Vigo, Campus de Orense, Las Lagunas, 32004 Orense, Spain
| | - Teresa Cabaleiro
- Laboratorio de Toxicología, Facultad de Ciencias, Universidad de Vigo, Campus de Orense, Las Lagunas, 32004 Orense, Spain
| | - Pilar Cano
- Departamento de Bioquímica y Biología Molecular III, Facultad de Medicina, Universidad Complutense, 28040 Madrid, Spain
| | - Ana I Esquifino
- Departamento de Bioquímica y Biología Molecular III, Facultad de Medicina, Universidad Complutense, 28040 Madrid, Spain
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Alvarez P, Cardinali D, Cano P, Rebollar P, Esquifino A. Prolactin daily rhythm in suckling male rabbits. J Circadian Rhythms 2005; 3:1. [PMID: 15649326 PMCID: PMC546204 DOI: 10.1186/1740-3391-3-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2004] [Accepted: 01/13/2005] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND: This study describes the 24-h changes in plasma prolactin levels, and dopamine (DA), serotonin (5HT), gamma-aminobutyric acid (GABA) and taurine concentration in median eminence and adenohypophysis of newborn male rabbits. METHODS: Animals were kept under controlled light-dark cycles (LD 16:8, lights on at 08:00 h), housed in individual metal cages, and fed ad libitum with free access to tap water. On day 1 after parturition, litter size was standardized to 8-9 to assure similar lactation conditions during the experiment. Groups of 6-7 suckling male rabbits were killed by decapitation on day 11 of life at six different time points during a 24-h period. RESULTS: Plasma prolactin levels changed significantly throughout the day, showing a peak at the beginning of the active phase (at 01:00 h) and a second maximum during the first part of the resting phase (at 13:00 h). Median eminence DA concentration also changed significantly during the day, peaking at the same time intervals as plasma prolactin. A single maximum (at 13:00 h) was found for adenohypophysial DA concentration. Individual adenohypophysial DA concentrations correlated significantly with their respective plasma prolactin levels. A maximum in median eminence 5HT concentration occurred at 21:00 h whereas adenohypophysial 5HT peaked at 13:00 h. Median eminence 5HT concentration and circulating prolactin correlated inversely. In the median eminence, GABA concentration attained maximal values at 21:00 h, whereas it reached a maximum at 13:00 h in the pituitary gland. Median eminence GABA concentration correlated inversely with circulating prolactin. In the median eminence, taurine values varied in a bimodal way showing two maxima, at the second half of the rest span and of the activity phase, respectively. In the adenohypophysis, minimal taurine levels coincided with the major plasma prolactin peak (at 01:00 h). Circulating prolactin and adenohypophysial taurine levels correlated inversely. CONCLUSION: The correlations among the changes in the neurotransmitters analyzed and circulating prolactin levels explain the circadian secretory pattern of the hormone in newborn male rabbits.
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Affiliation(s)
- Pilar Alvarez
- Departamento de Biología Celular, Facultad de Medicina, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Daniel Cardinali
- Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, 1121 Buenos Aires, Argentina
| | - Pilar Cano
- Departamento de Bioquímica y Biología Molecular III, Facultad de Medicina, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Pilar Rebollar
- Departamento de Producción Animal, E.T.S.I. Agrónomos, Universidad Politécnica de Madrid, Spain
| | - Ana Esquifino
- Departamento de Bioquímica y Biología Molecular III, Facultad de Medicina, Universidad Complutense de Madrid, 28040 Madrid, Spain
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Lafuente A, González-Carracedo A, Romero A, Cabaleiro T, Esquifino AI. Toxic effects of cadmium on the regulatory mechanism of dopamine and serotonin on prolactin secretion in adult male rats. Toxicol Lett 2005; 155:87-96. [PMID: 15585363 DOI: 10.1016/j.toxlet.2004.08.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2004] [Revised: 08/06/2004] [Accepted: 08/31/2004] [Indexed: 10/26/2022]
Abstract
This work was designed to analyze the effects of cadmium on the regulatory mechanism of prolactin in cadmium-exposed rats. Adult male rats were given cadmium at a dose of 25 ppm of cadmium chloride (CdCl2) in the drinking water for 1 month. At the end of the treatment, the rats were killed at six different time intervals throughout a 24 h cycle to measure circulating prolactin levels and dopamine and serotonin content in the median eminence and in both anterior and posterior pituitary. Control and cadmium-exposed animals exhibited significant time of day-dependent variations in plasma prolactin levels and in dopamine and serotonin concentration in all analyzed tissue. Cadmium exposure did not modify the mean values of the hormone around the clock but it modified the amplitude of the secretory peaks at 08:00 and 12:00 h. Cadmium decreased dopamine content in the median eminence, while increased its content in the posterior pituitary and induced a phase advanced peak at 20:00 h. On the other hand, serotonin content was not modified in the median eminence. Only differences in specific time points were observed, while serotonin concentration in anterior and posterior pituitary were increased in cadmium-treated rats. Differences in time peaks were also observed. The negative correlation between plasma prolactin and dopamine content in pituitary, and between plasma levels of the hormone and serotonin content in posterior pituitary, disappeared in cadmium-treated animals.
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Affiliation(s)
- A Lafuente
- Laboratorio de Toxicología, Facultad de Ciencias, Universidad de Vigo, Campus de Orense, Las Lagunas, 32004 Orense, Spain.
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