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Makwana R, Sanger GJ. Characterization of rat gastric myogenic contractions and modulation by oxytocin and arginine-vasopressin. Eur J Pharmacol 2023; 955:175906. [PMID: 37429518 DOI: 10.1016/j.ejphar.2023.175906] [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: 04/21/2023] [Revised: 07/06/2023] [Accepted: 07/07/2023] [Indexed: 07/12/2023]
Abstract
BACKGROUND Interstitial cells of Cajal generate slow wave gastric electrical activity, initiating spontaneous muscle contractions. This becomes dysrhythmic during nausea when [Arg8]-vasopressin (AVP) is also released. In human stomach AVP increased spontaneous contraction activity and muscle tone, not neuronally-mediated contractions. Rodents cannot vomit, releasing the related hormone, oxytocin (OT) instead. We hypothesised that rat stomach would behave differently. EXPERIMENTAL APPROACH Spontaneous and electrically-evoked (EFS) contractions were measured in rat forestomach and antrum circular muscle. Custom software defined spontaneous contractions by analysing eight motility parameters. RESULTS The forestomach was quiescent. Irregular antrum contractions became regular adjacent to the pylorus (1.7 ± 0.4 mN; 1.2 ± 0.1 contractions/min, n = 12). These were unaffected by tetrodotoxin (10-6 M), atropine (10-6 M) and L-NAME (3 × 10-4 M). In both regions, AVP (pEC50∼9.0) and OT (∼0.5 log10-unit less potent) caused contraction (greater in antrum), competitively antagonized by, respectively, SR49059 (pKB∼9.5) and L371257 (pKB∼9.0), reduced by tetrodotoxin but unaffected by atropine. In the antrum, AVP and OT (∼2 log10-units less potent/efficacious) regularized and increased spontaneous contraction amplitude, frequency, rates of contraction/decay. In both regions, EFS-evoked contractions, abolished by atropine/tetrodotoxin, were reduced by AVP and OT, with AVP more potent and efficacious, particularly in forestomach. CONCLUSION Irregular spontaneous contractions of gastric antrum suggest variable ICC-muscle coupling. AVP and less potently, OT, enhanced frequency and force of contractions via V1A and OT receptors. Compared with human, differences in contraction regularity, potency and ability of AVP/OT to affect neuronal function suggests caution when using rat stomach to model ICC functions and nauseagenic stimuli.
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Affiliation(s)
- Raj Makwana
- Blizard Institute, Queen Mary University of London, UK
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Yoshimura M, Conway-Campbell B, Ueta Y. Arginine vasopressin: Direct and indirect action on metabolism. Peptides 2021; 142:170555. [PMID: 33905792 PMCID: PMC8270887 DOI: 10.1016/j.peptides.2021.170555] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 04/12/2021] [Accepted: 04/15/2021] [Indexed: 02/07/2023]
Abstract
From its identification and isolation in 1954, arginine vasopressin (AVP) has attracted attention, not only for its peripheral functions such as vasoconstriction and reabsorption of water from kidney, but also for its central effects. As there is now considerable evidence that AVP plays a crucial role in feeding behavior and energy balance, it has become a promising therapeutic target for treating obesity or other obesity-related metabolic disorders. However, the underlying mechanisms for AVP regulation of these central processes still remain largely unknown. In this review, we will provide a brief overview of the current knowledge concerning how AVP controls energy balance and feeding behavior, focusing on physiological aspects including the relationship between AVP, circadian rhythmicity, and glucocorticoids.
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Affiliation(s)
- Mitsuhiro Yoshimura
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Japan; Translational Health Sciences, Bristol Medical School, University of Bristol, UK.
| | | | - Yoichi Ueta
- Department of Physiology, School of Medicine, University of Occupational and Environmental Health, Japan
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Abstract
PURPOSE OF REVIEW The neurohypophysial endocrine system is identified here as a potential target for therapeutic interventions toward improving obesity-related metabolic dysfunction, given its coinciding pleiotropic effects on psychological, neurological and metabolic systems that are disrupted in obesity. RECENT FINDINGS Copeptin, the C-terminal portion of the precursor of arginine-vasopressin, is positively associated with body mass index and risk of type 2 diabetes. Plasma oxytocin is decreased in obesity and several other conditions of abnormal glucose homeostasis. Recent data also show non-classical tissues, such as myocytes, hepatocytes and β-cells, exhibit responses to oxytocin and vasopressin receptor binding that may contribute to alterations in metabolic function. The modulation of anorexigenic and orexigenic pathways appears to be the dominant mechanism underlying the effects of oxytocin and vasopressin on body weight regulation; however, there are apparent limitations associated with their use in direct pharmacological applications. A clearer picture of their wider physiological effects is needed before either system can be considered for therapeutic use.
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Affiliation(s)
| | - Faidon Magkos
- Department of Nutrition, Exercise and Sports-Section of Obesity Research, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C; Building 2-85, Room H134, Copenhagen, Denmark.
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Psilopanagioti A, Nikou S, Papadaki H. Nucleobindin-2/Nesfatin-1 in the Human Hypothalamus Is Reduced in Obese Subjects and Colocalizes with Oxytocin, Vasopressin, Melanin-Concentrating Hormone, and Cocaine- and Amphetamine-Regulated Transcript. Neuroendocrinology 2019; 108:190-200. [PMID: 30625474 DOI: 10.1159/000496731] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Accepted: 01/09/2019] [Indexed: 11/19/2022]
Abstract
BACKGROUND/AIMS Nesfatin-1, processed from nucleobindin-2 (NUCB2), is a potent anorexigenic peptide being expressed in rodent hypothalamic nuclei and involved in the regulation of feeding behavior and body weight in animals. The present study aimed to investigate NUCB2/nesfatin-1 protein expression in the human hypothalamus as well as its correlation with body weight. METHODS Sections of hypothalamus and adjacent cholinergic basal forebrain nuclei, including the nucleus basalis of Meynert (NBM) and the diagonal band of Broca (DBB), from 25 autopsy cases (17 males, 8 females; 8 lean, 9 overweight, 8 obese) were examined using immunohistochemistry and double immunofluorescence labeling. RESULTS Prominent NUCB2/nesfatin-1 immunoexpression was detected in supraoptic, paraventricular, and infundibular nuclei, lateral hypothalamic area (LHA)/perifornical region, and NBM/DBB. NUCB2/nesfatin-1 was found to extensively colocalize with (a) oxytocin and vasopressin in paraventricular and supraoptic nuclei, (b) melanin-concentrating hormone in the LHA, and (c) cocaine- and amphetamine-regulated transcript in infundibular and paraventricular nuclei and LHA. Interestingly, in the LHA, NUCB2/nesfatin-1 protein expression was significantly decreased in obese, compared with lean (p < 0.01) and overweight (p < 0.05) subjects. CONCLUSIONS The findings of the present study are suggestive of a potential role for NUCB2/nesfatin-1 as an integral regulator of food intake and energy homeostasis in the human hypothalamus. In the LHA, an appetite- and reward-related brain area, reduced NUCB2/nesfatin-1 immunoexpression may contribute to dysregulation of homeostatic and/or hedonic feeding behavior and obesity. NUCB2/nesfatin-1 localization in NBM/DBB might imply its participation in the neuronal circuitry controlling cognitive influences on food intake and give impetus towards unraveling additional biological actions of NUCB2/nesfatin-1 in human neuronal networks.
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Affiliation(s)
- Aristea Psilopanagioti
- Department of Anatomy-Histology-Embryology, School of Medicine, University of Patras, Patras, Greece,
| | - Sofia Nikou
- Department of Anatomy-Histology-Embryology, School of Medicine, University of Patras, Patras, Greece
| | - Helen Papadaki
- Department of Anatomy-Histology-Embryology, School of Medicine, University of Patras, Patras, Greece
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Santoso P, Nakata M, Ueta Y, Yada T. Suprachiasmatic vasopressin to paraventricular oxytocin neurocircuit in the hypothalamus relays light reception to inhibit feeding behavior. Am J Physiol Endocrinol Metab 2018; 315:E478-E488. [PMID: 28174180 DOI: 10.1152/ajpendo.00338.2016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Light synchronizes the body's circadian rhythms by modulating the master clock located in the suprachiasmatic nucleus (SCN) of the hypothalamus. In modern lifestyles that run counter to normal circadian rhythms, the extended and/or irregular light exposure impairs circadian rhythms and, consequently, promotes feeding and metabolic disorders. However, the neuronal pathway through which light is coupled to feeding behavior is less elucidated. The present study employed the light exposure during the dark phase of the day in rats and observed its effect on neuronal activity and feeding behavior. Light exposure acutely suppressed food intake and elevated c-Fos expression in the AVP neurons of SCN and the oxytocin (Oxt) neurons of paraventricular nucleus (PVN) in the hypothalamus. The light-induced suppression of food intake was abolished by blockade of the Oxt receptor in the brain. Retrograde tracer analysis demonstrated the projection of SCN AVP neurons to the PVN. Furthermore, intracerebroventricular injection of AVP suppressed food intake and increased c-Fos in PVN Oxt neurons. Intra-PVN injection of AVP exerted a stronger anorexigenic effect than intracerebroventriclar injection. AVP also induced intracellular Ca2+ signaling and increased firing frequency in Oxt neurons in PVN slices. These results reveal the novel neurocircuit from SCN AVP to PVN Oxt that relays light reception to inhibition of feeding behavior. This light-induced neurocircuit may serve as a pathway for forming the circadian feeding rhythm and linking irregular light exposure to arrhythmic feeding and, consequently, obesity and metabolic diseases.
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Affiliation(s)
- Putra Santoso
- Department of Physiology, Division of Integrative Physiology, Jichi Medical University School of Medicine, Shimotsuke, Tochigi , Japan
| | - Masanori Nakata
- Department of Physiology, Division of Integrative Physiology, Jichi Medical University School of Medicine, Shimotsuke, Tochigi , Japan
| | - Yoichi Ueta
- Department of Physiology, University of Occupational and Environmental Health , Kitakyushu , Japan
| | - Toshihiko Yada
- Department of Physiology, Division of Integrative Physiology, Jichi Medical University School of Medicine, Shimotsuke, Tochigi , Japan
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Chambers KC. Conditioned taste aversions. World J Otorhinolaryngol Head Neck Surg 2018; 4:92-100. [PMID: 30035267 PMCID: PMC6051479 DOI: 10.1016/j.wjorl.2018.02.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 02/26/2018] [Indexed: 11/21/2022] Open
Abstract
When one becomes ill after consuming a meal, there is a propensity to target a particular taste as the cause of the illness. The qualities of the taste most likely targeted include more novel, less preferred, and higher protein content. This association between a particular taste and illness is a form of learning that is termed conditioned taste aversion (CTA). A consequence of the learned association is that the taste will become aversive. When experiencing the taste again, individuals will show aversive reactions such as expressions of loathing, will experience mimicked illness sensations such as nausea, and subsequently, will avoid further exposure to the taste. The ability to acquire CTA occurs across species and across ages within a species. In the rat animal model, however, age differences exist in the capability of acquiring CTAs when increasingly longer intervals are imposed between consumption of a novel sweet solution and onset of illness. Pups have a decreased ability compared to young adults while aged rats have an increased ability. Evidence suggests that the failure of pups to acquire CTA at longer intervals is due to an immature retrieval mechanism and the facilitated ability of aged rats is due to a compromised clock mechanism that tracks the passage of time. Learned taste-illness association serves the critical function of informing individuals of the toxic nature of certain foods, thus preventing further illness and potentially death. Additionally, it contributes to the hypophagia observed during cancer chemotherapy and may contribute to the hypophagia found while suffering from bacterial infection, chronic medical conditions such as cancer, and restrictive food intake disorders such as anorexia nervosa.
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Nagarajan G, Jurkevich A, Kang SW, Kuenzel WJ. Diencephalic and septal structures containing the avian vasotocin receptor (V1aR) involved in the regulation of food intake in chickens, Gallus gallus. Physiol Behav 2016; 164:268-76. [PMID: 27317836 DOI: 10.1016/j.physbeh.2016.06.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Revised: 05/23/2016] [Accepted: 06/14/2016] [Indexed: 12/31/2022]
Abstract
Recently, it was found that the avian central vasotocin receptor (V1aR) is associated with the regulation of food intake. To identify V1aR-containing brain structures regulating food intake, a selective V1aR antagonist SR-49059 that induced food intake was administrated intracerebroventricularly in male chickens followed by detection of brain structures using FOS immunoreactivity. Particularly, the hypothalamic core region of the paraventricular nucleus, lateral hypothalamic area, dorsomedial hypothalamic nucleus, a subnucleus of the central extended amygdalar complex [dorsolateral bed nucleus of the stria terminalis], medial septal nucleus and caudal brainstem [nucleus of the solitary tract] showed significantly increased FOS-ir cells. On the other hand, the supraoptic nucleus of the preoptic area and the nucleus of the hippocampal commissure of the septum showed suppressed FOS immunoreactivity in the V1aR antagonist treatment group. Further investigation revealed that neuronal activity of arginine vasotocin (AVT-ir) magnocellular neurons in the supraoptic nucleus, preoptic periventricular nucleus, paraventricular nucleus and ventral periventricular hypothalamic nucleus and most likely corticotropin releasing hormone (CRH-ir) neurons in the nucleus of the hippocampal commissure were reduced following the antagonist treatment. Dual immunofluorescence labeling results showed that perikarya of AVT-ir magnocellular neurons in the preoptic area and hypothalamus were colabeled with V1aR. Within the nucleus of the hippocampal commissure, CRH-ir neurons were shown in close contact with V1aR-ir glial cells. Results of the present study suggest that the V1aR plays a role in the regulation of food intake by modulating neurons that synthesize and release anorectic neuropeptides in the avian brain.
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Affiliation(s)
- Gurueswar Nagarajan
- The Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Alexander Jurkevich
- The Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Seong W Kang
- The Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA
| | - Wayne J Kuenzel
- The Center of Excellence for Poultry Science, University of Arkansas, Fayetteville, AR 72701, USA.
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Central action of ELABELA reduces food intake and activates arginine vasopressin and corticotropin-releasing hormone neurons in the hypothalamic paraventricular nucleus. Neuroreport 2015; 26:820-6. [DOI: 10.1097/wnr.0000000000000431] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Blevins JE, Baskin DG. Translational and therapeutic potential of oxytocin as an anti-obesity strategy: Insights from rodents, nonhuman primates and humans. Physiol Behav 2015; 152:438-49. [PMID: 26013577 DOI: 10.1016/j.physbeh.2015.05.023] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 05/19/2015] [Accepted: 05/21/2015] [Indexed: 12/15/2022]
Abstract
The fact that more than 78 million adults in the US are considered overweight or obese highlights the need to develop new, effective strategies to treat obesity and its associated complications, including type 2 diabetes, kidney disease and cardiovascular disease. While the neurohypophyseal peptide oxytocin (OT) is well recognized for its peripheral effects to stimulate uterine contraction during parturition and milk ejection during lactation, release of OT within the brain is implicated in prosocial behaviors and in the regulation of energy balance. Previous findings indicate that chronic administration of OT decreases food intake and weight gain or elicits weight loss in diet-induced obese (DIO) mice and rats. Furthermore, chronic systemic treatment with OT largely reproduces the effects of central administration to reduce weight gain in DIO and genetically obese rodents at doses that do not appear to result in tolerance. These findings have now been recently extended to more translational models of obesity showing that chronic subcutaneous or intranasal OT treatment is sufficient to elicit body weight loss in DIO nonhuman primates and pre-diabetic obese humans. This review assesses the potential use of OT as a therapeutic strategy for treatment of obesity in rodents, nonhuman primates, and humans, and identifies potential mechanisms that mediate this effect.
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Affiliation(s)
- James E Blevins
- VA Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA; Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA.
| | - Denis G Baskin
- VA Puget Sound Health Care System, Office of Research and Development, Medical Research Service, Department of Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA; Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
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Lucio-Oliveira F, Traslaviña G, Borges B, Franci C. Modulation of the activity of vasopressinergic neurons by estrogen in rats refed with normal or sodium-free food after fasting. Neuroscience 2015; 284:325-336. [DOI: 10.1016/j.neuroscience.2014.09.076] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 09/26/2014] [Accepted: 09/30/2014] [Indexed: 11/25/2022]
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Zhou L, Sun WL, Young AB, Lee K, McGinty JF, See RE. Oxytocin reduces cocaine seeking and reverses chronic cocaine-induced changes in glutamate receptor function. Int J Neuropsychopharmacol 2014; 18:pyu009. [PMID: 25539504 PMCID: PMC4368863 DOI: 10.1093/ijnp/pyu009] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
BACKGROUND Oxytocin, a neurohypophyseal neuropeptide, is a potential mediator and regulator of drug addiction. However, the cellular mechanisms of oxytocin in drug seeking remain unknown. METHODS In the present study, we used a self-administration/reinstatement model to study the effects of oxytocin on cocaine seeking and its potential interaction with glutamate function at the receptor level. RESULTS Systemic oxytocin dose-dependently reduced cocaine self-administration during various schedules of reinforcement, including fixed ratio 1, fixed ratio 5, and progressive ratio. Oxytocin also attenuated reinstatement to cocaine seeking induced by cocaine prime or conditioned cues. Western-blot analysis indicated that oxytocin increased phosphorylation of the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid-type glutamate receptor GluA1 subunit at the Ser 845 site with or without accompanying increases in phosphorylation of extracellular signal-regulated kinase, in several brain regions, including the prefrontal cortex, bed nucleus of the stria terminalis, amygdala, and dorsal hippocampus. Immunoprecipitation of oxytocin receptor and GluA1 subunit receptors further demonstrated a physical interaction between these 2 receptors, although the interaction was not influenced by chronic cocaine or oxytocin treatment. Oxytocin also attenuated sucrose seeking in a GluA1- or extracellular-signal-regulated kinase-independent manner. CONCLUSIONS These findings suggest that oxytocin mediates cocaine seeking through interacting with glutamate receptor systems via second messenger cascades in mesocorticolimbic regions.
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Affiliation(s)
- Luyi Zhou
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina (Drs Zhou, Sun, Young, Lee, McGinty, and See)
| | - Wei-Lun Sun
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina (Drs Zhou, Sun, Young, Lee, McGinty, and See)
| | - Amy B Young
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina (Drs Zhou, Sun, Young, Lee, McGinty, and See)
| | - Kunhee Lee
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina (Drs Zhou, Sun, Young, Lee, McGinty, and See)
| | - Jacqueline F McGinty
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina (Drs Zhou, Sun, Young, Lee, McGinty, and See)
| | - Ronald E See
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina (Drs Zhou, Sun, Young, Lee, McGinty, and See).
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Altirriba J, Poher AL, Caillon A, Arsenijevic D, Veyrat-Durebex C, Lyautey J, Dulloo A, Rohner-Jeanrenaud F. Divergent effects of oxytocin treatment of obese diabetic mice on adiposity and diabetes. Endocrinology 2014; 155:4189-201. [PMID: 25157455 DOI: 10.1210/en.2014-1466] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Oxytocin has been suggested as a novel therapeutic against obesity, because it induces weight loss and improves glucose tolerance in diet-induced obese rodents. A recent clinical pilot study confirmed the oxytocin-induced weight-reducing effect in obese nondiabetic subjects. Nevertheless, the mechanisms involved and the impact on the main comorbidity associated with obesity, type 2 diabetes, are unknown. Lean and ob/ob mice (model of obesity, hyperinsulinemia, and diabetes) were treated for 2 weeks with different doses of oxytocin, analogues with longer half-life (carbetocin) or higher oxytocin receptor specificity ([Thr4,Gly7]-oxytocin). Food and water intake, body weight, and glycemia were measured daily. Glucose, insulin, and pyruvate tolerance, body composition, several hormones, metabolites, gene expression, as well as enzyme activities were determined. Although no effect of oxytocin on the main parameters was observed in lean mice, the treatment dose-dependently reduced food intake and body weight gain in ob/ob animals. Carbetocin behaved similarly to oxytocin, whereas [Thr4,Gly7]-oxytocin (TGOT) and a low oxytocin dose decreased body weight gain without affecting food intake. The body weight gain-reducing effect was limited to the fat mass only, with decreased lipid uptake, lipogenesis, and inflammation, combined with increased futile cycling in abdominal adipose tissue. Surprisingly, oxytocin treatment of ob/ob mice was accompanied by a worsening of basal glycemia and glucose tolerance, likely due to increased corticosterone levels and stimulation of hepatic gluconeogenesis. These results impose careful selection of the conditions in which oxytocin treatment should be beneficial for obesity and its comorbidities, and their relevance for human pathology needs to be determined.
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Affiliation(s)
- Jordi Altirriba
- Laboratory of Metabolism (J.A., A.-L.P., A.C., C.V.-D., J.L., F.R.-J.), Department of Internal Medicine Specialties, Faculty of Medicine, University of Geneva, Geneva 1211, Switzerland; and Department of Medicine/Physiology (D.A., A.D.), University of Fribourg, Fribourg 1700, Switzerland
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Abstract
The control of energy intake is complex, including mechanisms that act independently (e.g. distention, osmotic effects, fuel-sensing) as well as interacting factors that are likely to affect feeding via their effects on hepatic oxidation. Effects of ruminant diets on feed intake vary greatly because of variation in their filling effects, as well as the type and temporal absorption of fuels. Effects of nutrients on endocrine response and gene expression affect energy partitioning, which in turn affects feeding behaviour by altering clearance of fuels from the blood. Dominant mechanisms controlling feed intake change with physiological state, which is highly variable among ruminants, especially through the lactation cycle. Ruminal distention might dominate control of feed intake when ruminants consume low-energy diets or when energy requirements are high, but fuel-sensing by tissues is likely to dominate control of feed intake when fuel supply is in excess of that required. The liver is likely to be a primary sensor of energy status because it is supplied by fuels from the portal drained viscera as well as the general circulation, it metabolises a variety of fuels derived from both the diet and tissues, and a signal related to hepatic oxidation of fuels is conveyed to feeding centres in the brain by hepatic vagal afferents stimulating or inhibiting feeding, depending on its energy status. The effects of somatotropin on export of fuels by milk secretion, effects of insulin on gluconeogenesis, and both on mobilisation and repletion of tissues, determine fuel availability and feed intake over the lactation cycle. Control of feed intake by hepatic energy status, affected by oxidation of fuels, is an appealing conceptual model because it integrates effects of various fuels and physiological states on feeding behaviour.
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Sobrino Crespo C, Perianes Cachero A, Puebla Jiménez L, Barrios V, Arilla Ferreiro E. Peptides and food intake. Front Endocrinol (Lausanne) 2014; 5:58. [PMID: 24795698 PMCID: PMC4005944 DOI: 10.3389/fendo.2014.00058] [Citation(s) in RCA: 127] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Accepted: 04/09/2014] [Indexed: 12/19/2022] Open
Abstract
The mechanisms for controlling food intake involve mainly an interplay between gut, brain, and adipose tissue (AT), among the major organs. Parasympathetic, sympathetic, and other systems are required for communication between the brain satiety center, gut, and AT. These neuronal circuits include a variety of peptides and hormones, being ghrelin the only orexigenic molecule known, whereas the plethora of other factors are inhibitors of appetite, suggesting its physiological relevance in the regulation of food intake and energy homeostasis. Nutrients generated by food digestion have been proposed to activate G-protein-coupled receptors on the luminal side of enteroendocrine cells, e.g., the L-cells. This stimulates the release of gut hormones into the circulation such as glucagon-like peptide-1 (GLP-1), oxyntomodulin, pancreatic polypeptides, peptide tyrosine tyrosine, and cholecystokinin, which inhibit appetite. Ghrelin is a peptide secreted from the stomach and, in contrast to other gut hormones, plasma levels decrease after a meal and potently stimulate food intake. Other circulating factors such as insulin and leptin relay information regarding long-term energy stores. Both hormones circulate at proportional levels to body fat content, enter the CNS proportionally to their plasma levels, and reduce food intake. Circulating hormones can influence the activity of the arcuate nucleus (ARC) neurons of the hypothalamus, after passing across the median eminence. Circulating factors such as gut hormones may also influence the nucleus of the tractus solitarius (NTS) through the adjacent circumventricular organ. On the other hand, gastrointestinal vagal afferents converge in the NTS of the brainstem. Neural projections from the NTS, in turn, carry signals to the hypothalamus. The ARC acts as an integrative center, with two major subpopulations of neurons influencing appetite, one of them coexpressing neuropeptide Y and agouti-related protein (AgRP) that increases food intake, whereas the other subpopulation coexpresses pro-opiomelanocortin (POMC) and cocaine and amphetamine-regulated transcript that inhibits food intake. AgRP antagonizes the effects of the POMC product, α-melanocyte-stimulating hormone (α-MSH). Both populations project to areas important in the regulation of food intake, including the hypothalamic paraventricular nucleus, which also receives important inputs from other hypothalamic nuclei.
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Affiliation(s)
- Carmen Sobrino Crespo
- Biochemistry and Molecular Biology Unit, Department of Systems Biology, Faculty of Medicine, University of Alcalá, Alcalá de Henares, Spain
| | - Aránzazu Perianes Cachero
- Biochemistry and Molecular Biology Unit, Department of Systems Biology, Faculty of Medicine, University of Alcalá, Alcalá de Henares, Spain
| | - Lilian Puebla Jiménez
- Biochemistry and Molecular Biology Unit, Department of Systems Biology, Faculty of Medicine, University of Alcalá, Alcalá de Henares, Spain
| | - Vicente Barrios
- Department of Endocrinology, Hospital Infantil Universitario Niño Jesús, Instituto de Investigación La Princesa, Madrid, Spain
- Centro de Investigación Biomédica en Red Fisiopatología Obesidad y Nutrición, Instituto de Salud Carlos III, Madrid, Spain
| | - Eduardo Arilla Ferreiro
- Biochemistry and Molecular Biology Unit, Department of Systems Biology, Faculty of Medicine, University of Alcalá, Alcalá de Henares, Spain
- *Correspondence: Eduardo Arilla Ferreiro, Biochemistry and Molecular Biology Unit, Department of Systems Biology, Faculty of Medicine, University of Alcalá, Alcalá de Henares, Madrid E-28871, Spain e-mail:
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Mullis K, Kay K, Williams DL. Oxytocin action in the ventral tegmental area affects sucrose intake. Brain Res 2013; 1513:85-91. [PMID: 23548602 PMCID: PMC3739708 DOI: 10.1016/j.brainres.2013.03.026] [Citation(s) in RCA: 93] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 03/20/2013] [Accepted: 03/23/2013] [Indexed: 11/16/2022]
Abstract
Brain oxytocin is known to play a role in the control of food intake, and recent studies suggest that stimulation of central oxytocin receptors selectively suppresses carbohydrate intake. The specific oxytocin projection sites and receptor populations involved in this response are as yet unidentified. We hypothesized that oxytocin receptors in the ventral tegmental area (VTA) may play a role in limiting sucrose intake, because the VTA is known to influence palatable food intake. We first performed a dose response study in which we observed that intra-VTA oxytocin injection significantly suppressed intake of a 10% sucrose solution during a 30-min test session by 13.35-20.5% relative to vehicle treatment. Doses of intra-VTA oxytocin that suppressed sucrose intake had no effect on water intake. Next we examined the effects of two oxytocin receptor antagonists, (d(CH2)5(1),Tyr(Me)(2),Orn(8))-Oxytocin (OVT) and L-368,899. Each of these antagonists significantly increased 10% sucrose intake by 17-20.5% relative to vehicle when delivered directly into the VTA, at doses subthreshold for effect if injected into the cerebral ventricles. Finally, we observed that the effect of intra-VTA oxytocin to suppress 10% sucrose intake was significantly attenuated by pretreatment with L-368,899, supporting the suggestion that the VTA oxytocin treatment suppresses intake through action at oxytocin receptors. These findings support the suggestion that endogenous oxytocin action within the VTA suppresses sucrose intake. We conclude that oxytocin receptors in the VTA play a physiologic role in the control of sucrose ingestion.
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Affiliation(s)
- Kiersten Mullis
- Department of Psychology & Program in Neuroscience Florida State University, Box 3064301, Tallahassee FL, 32036-4301 USA
| | - Kristen Kay
- Department of Psychology & Program in Neuroscience Florida State University, Box 3064301, Tallahassee FL, 32036-4301 USA
| | - Diana L. Williams
- Department of Psychology & Program in Neuroscience Florida State University, Box 3064301, Tallahassee FL, 32036-4301 USA
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16
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Yamashita M, Takayanagi Y, Yoshida M, Nishimori K, Kusama M, Onaka T. Involvement of prolactin-releasing peptide in the activation of oxytocin neurones in response to food intake. J Neuroendocrinol 2013; 25:455-65. [PMID: 23363338 PMCID: PMC3664423 DOI: 10.1111/jne.12019] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2012] [Revised: 12/10/2012] [Accepted: 12/26/2012] [Indexed: 12/16/2022]
Abstract
Food intake activates neurones expressing prolactin-releasing peptide (PrRP) in the medulla oblongata and oxytocin neurones in the hypothalamus. Both PrRP and oxytocin have been shown to have an anorexic action. In the present study, we investigated whether the activation of oxytocin neurones following food intake is mediated by PrRP. We first examined the expression of PrRP receptors (also known as GPR10) in rats. Immunoreactivity of PrRP receptors was observed in oxytocin neurones and in vasopressin neurones in the paraventricular and supraoptic nuclei of the hypothalamus and in the bed nucleus of the stria terminalis. Application of PrRP to isolated supraoptic nuclei facilitated the release of oxytocin and vasopressin. In mice, re-feeding increased the expression of Fos protein in oxytocin neurones of the hypothalamus and bed nucleus of the stria terminalis. The increased expression of Fos protein in oxytocin neurones following re-feeding or i.p. administration of cholecystokinin octapeptide (CCK), a peripheral satiety factor, was impaired in PrRP-deficient mice. CCK-induced oxytocin increase in plasma was also impaired in PrRP-deficient mice. Furthermore, oxytocin receptor-deficient mice showed an increased meal size, as reported in PrRP-deficient mice and in CCKA receptor-deficient mice. These findings suggest that PrRP mediates, at least in part, the activation of oxytocin neurones in response to food intake, and that the CCK-PrRP-oxytocin pathway plays an important role in the control of the termination of each meal.
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Affiliation(s)
- M Yamashita
- Division of Brain and Neurophysiology, Department of Physiology, Jichi Medical University, Shimotsuke-shi, Japan
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17
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Ebstein RP, Knafo A, Mankuta D, Chew SH, Lai PS. The contributions of oxytocin and vasopressin pathway genes to human behavior. Horm Behav 2012; 61:359-79. [PMID: 22245314 DOI: 10.1016/j.yhbeh.2011.12.014] [Citation(s) in RCA: 181] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2011] [Revised: 12/20/2011] [Accepted: 12/21/2011] [Indexed: 01/23/2023]
Abstract
Arginine vasopressin (AVP) and oxytocin (OXT) are social hormones and mediate affiliative behaviors in mammals and as recently demonstrated, also in humans. There is intense interest in how these simple nonapeptides mediate normal and abnormal behavior, especially regarding disorders of the social brain such as autism that are characterized by deficits in social communication and social skills. The current review examines in detail the behavioral genetics of the first level of human AVP-OXT pathway genes including arginine vasopressin 1a receptor (AVPR1a), oxytocin receptor (OXTR), AVP (AVP-neurophysin II [NPII]) and OXT (OXT neurophysin I [NPI]), oxytocinase/vasopressinase (LNPEP), ADP-ribosyl cyclase (CD38) and arginine vasopressin 1b receptor (AVPR1b). Wherever possible we discuss evidence from a variety of research tracks including molecular genetics, imaging genomics, pharmacology and endocrinology that support the conclusions drawn from association studies of social phenotypes and detail how common polymorphisms in AVP-OXT pathway genes contribute to the behavioral hard wiring that enables individual Homo sapiens to interact successfully with conspecifics. This article is part of a Special Issue entitled Oxytocin, Vasopressin, and Social Behavior.
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Affiliation(s)
- Richard P Ebstein
- Department of Psychology, National University of Singapore, Singapore.
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18
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Lv SY, Yang YJ, Qin YJ, Mo JR, Wang NB, Wang YJ, Chen Q. Central apelin-13 inhibits food intake via the CRF receptor in mice. Peptides 2012; 33:132-8. [PMID: 22108714 DOI: 10.1016/j.peptides.2011.11.011] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 11/07/2011] [Accepted: 11/07/2011] [Indexed: 11/24/2022]
Abstract
Apelin, the novel identified peptide, is the endogenous ligand for the APJ. Previous studies have reported the effect of apelin on food intake, however the action of acute central injected apelin on food intake in mice remains unknown. The present study was designed to investigate the mechanism as well as the effect of central apelin-13 on food intake in mice. During the dark period, the cumulative food intake was significantly decreased at 4h after the intracerebroventricular (i.c.v.) injection of 1 and 3μg/mouse apelin-13 and the period food intake was significantly reduced during 2-4h after treatment. In the fasted mice, the cumulative food intake was significantly decreased at 2 and 4h after injection of 3μg/mouse apelin-13. The cumulative water intake was significantly reduced by apelin-13 (3μg/mouse) at 4h after injection in freely feeding and fasted mice. However, during light period, apelin-13 had no influence on food and water intake in freely feeding mice. The APJ receptor antagonist apelin-13(F13A) (6μg/mouse) and the corticotrophin-releasing factor (CRF) receptor antagonist α-helical CRF(9-41) (3μg/mouse) could reverse the inhibitory effect on cumulative food intake/0-4h induced by apelin-13 (3μg/mouse) in freely feeding mice during the dark period, whereas the anorexic effect could not be antagonized by the arginie vasopressin (AVP) receptor antagonist deamino(CH(2))(5)Tyr(Me)AVP (0.5μg/mouse). Taken together, these results suggest that central apelin-13 inhibits food intake in mice and it seems that APJ receptor and CRF receptor, but not AVP receptor, might be involved in this process.
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Affiliation(s)
- Shuang-Yu Lv
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, Lanzhou University, 222 Tian Shui South Road, Lanzhou 730000, PR China
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19
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de Kloet AD, Krause EG, Scott KA, Foster MT, Herman JP, Sakai RR, Seeley RJ, Woods SC. Central angiotensin II has catabolic action at white and brown adipose tissue. Am J Physiol Endocrinol Metab 2011; 301:E1081-91. [PMID: 21862725 PMCID: PMC3233774 DOI: 10.1152/ajpendo.00307.2011] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Considerable evidence implicates the renin-angiotensin system (RAS) in the regulation of energy balance. To evaluate the role of the RAS in the central nervous system regulation of energy balance, we used osmotic minipumps to chronically administer angiotensin II (Ang II; icv; 0.7 ng/min for 24 days) to adult male Long-Evans rats, resulting in reduced food intake, body weight gain, and adiposity. The decrease in body weight and adiposity occurred relative to both ad libitum- and pair-fed controls, implying that reduced food intake in and of itself does not underlie all of these effects. Consistent with this, rats administered Ang II had increased whole body heat production and oxygen consumption. Additionally, chronic icv Ang II increased uncoupling protein-1 and β(3)-adrenergic receptor expression in brown adipose tissue and β3-adrenergic receptor expression in white adipose tissue, which is suggestive of enhanced sympathetic activation and thermogenesis. Chronic icv Ang II also increased hypothalamic agouti-related peptide and decreased hypothalamic proopiomelanocortin expression, consistent with a state of energy deficit. Moreover, chronic icv Ang II increased the anorectic corticotrophin- and thyroid-releasing hormones within the hypothalamus. These results suggest that Ang II acts in the brain to promote negative energy balance and that contributing mechanisms include an alteration in the hypothalamic circuits regulating energy balance, a decrease in food intake, an increase in energy expenditure, and an increase in sympathetic activation of brown and white adipose tissue.
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MESH Headings
- Adipose Tissue, Brown/drug effects
- Adipose Tissue, Brown/metabolism
- Adipose Tissue, White/drug effects
- Adipose Tissue, White/metabolism
- Angiotensin II/administration & dosage
- Angiotensin II/pharmacology
- Animals
- Body Weight/drug effects
- Brain/drug effects
- Dose-Response Relationship, Drug
- Down-Regulation/drug effects
- Drug Evaluation, Preclinical
- Eating/drug effects
- Infusion Pumps, Implantable
- Infusions, Intraventricular
- Infusions, Subcutaneous
- Male
- Metabolism/drug effects
- Rats
- Rats, Long-Evans
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Affiliation(s)
- Annette D de Kloet
- Department of Physiology and Functional Genomics, College of Medicine, University of Florida, Gainesville, Florida 32611, USA.
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20
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Sinno MH, Coquerel Q, Boukhettala N, Coëffier M, Gallas S, Terashi M, Ibrahim A, Breuillé D, Déchelotte P, Fetissov SO. Chemotherapy-induced anorexia is accompanied by activation of brain pathways signaling dehydration. Physiol Behav 2010; 101:639-48. [DOI: 10.1016/j.physbeh.2010.09.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2010] [Revised: 08/17/2010] [Accepted: 09/22/2010] [Indexed: 02/07/2023]
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21
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Kohno D, Nakata M, Maejima Y, Shimizu H, Sedbazar U, Yoshida N, Dezaki K, Onaka T, Mori M, Yada T. Nesfatin-1 neurons in paraventricular and supraoptic nuclei of the rat hypothalamus coexpress oxytocin and vasopressin and are activated by refeeding. Endocrinology 2008; 149:1295-301. [PMID: 18048495 DOI: 10.1210/en.2007-1276] [Citation(s) in RCA: 203] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Nesfatin-1, a newly discovered satiety molecule, is located in the hypothalamic nuclei, including the paraventricular nucleus (PVN) and supraoptic nucleus (SON). In this study, fine localization and regulation of nesfatin-1 neurons in the PVN and SON were investigated by immunohistochemistry of neuropeptides and c-Fos. In the PVN, 24% of nesfatin-1 neurons overlapped with oxytocin, 18% with vasopressin, 13% with CRH, and 12% with TRH neurons. In the SON, 35% of nesfatin-1 neurons overlapped with oxytocin and 28% with vasopressin. After a 48-h fast, refeeding for 2 h dramatically increased the number of nesfatin-1 neurons expressing c-Fos immunoreactivity by approximately 10 times in the PVN and 30 times in the SON, compared with the fasting controls. In the SON, refeeding also significantly increased the number of nesfatin-1-immunoreactive neurons and NUCB2 mRNA expression, compared with fasting. These results indicate that nesfatin-1 neurons in the PVN and SON highly overlap with oxytocin and vasopressin neurons and that they are activated markedly by refeeding. Feeding-activated nesfatin-1 neurons in the PVN and SON could play a role in the postprandial regulation of feeding behavior and energy homeostasis.
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Affiliation(s)
- Daisuke Kohno
- Division of Integrative Physiology, Department of Physiology, Jichi Medical University, School of Medicine, Tochigi 329-0498, Japan
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22
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Ho SSN, Chow BKC, Yung WH. Serotonin increases the excitability of the hypothalamic paraventricular nucleus magnocellular neurons. Eur J Neurosci 2007; 25:2991-3000. [PMID: 17561813 DOI: 10.1111/j.1460-9568.2007.05547.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recent evidence that 5-hydroxytryptamine (5-HT or serotonin) enhances the release and the gene expression of vasopressin and oxytocin in the hypothalamic paraventricular nucleus (PVN) suggests that 5-HT can excite the PVN magnocellular neurons. The objective of this study was to examine the underlying mechanisms for such excitatory action in the electrophysiologically identified hypothalamic PVN magnocellular neurons in rats using whole-cell patch-clamp. We found that 5-HT weakly depolarizes 33.3% of PVN magnocellular neurons in the presence of tetrodotoxin. A minuscule inward current was produced by 5-HT in 48% of the cells, which was attenuated when the 5-HT(4) antagonist GR113808 or the 5-HT(7) antagonist SB269970 was added. In addition, 5-HT reduced the frequency of miniature inhibitory postsynaptic currents in a dose-dependent manner. This inhibition was mimicked by the 5-HT(1B) agonist CP93129, and reversed in the presence of 5-HT(1B) antagonists cyanopindolol and SB224289. Besides, 5-HT induced a biphasic effect on the frequency of miniature excitatory postsynaptic currents, comprising a transient inhibition and a delayed concentration-dependent excitation (onset latency approximately 5 min). The facilitation was mimicked by the 5-HT(2A/2C) agonist DOI and abolished in the presence of the 5-HT(2C) antagonist RS102221. Our findings reveal that 5-HT directly increases the excitability of the PVN magnocellular neurons via multiple receptor subtypes and mechanisms. This may help understanding the regulation of 5-HT-induced hormone release and feeding behavior in the PVN.
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Affiliation(s)
- Sara S N Ho
- Department of Zoology, The University of Hong Kong, Pokfulam, Hong Kong, China
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23
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Tasker JG. Rapid glucocorticoid actions in the hypothalamus as a mechanism of homeostatic integration. Obesity (Silver Spring) 2006; 14 Suppl 5:259S-265S. [PMID: 17021378 DOI: 10.1038/oby.2006.320] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The hypothalamic paraventricular nucleus (PVN) is a major integrative site for the control of homeostasis, including energy balance, through coordinated regulation of neuroendocrine and autonomic outputs. However, cross-talk regulation of PVN neuroendocrine and preautonomic systems is poorly understood. The stress response invokes the coordinated control of motor, hormonal, and vegetative systems to establish homeostasis after an environmental perturbation. Elevated stress levels of circulating glucocorticoids give rise to multiple, complex physiological effects. The complexity of the glucocorticoid actions is caused by the wide range of glucocorticoid target tissues and to the broad time scale over which the actions occur. Recent studies have revealed rapid glucocorticoid actions in the hypothalamus that may provide an integrative signal linking stress with the regulation of energy and fluid homeostasis. Glucocorticoids inhibit PVN and supraoptic nucleus neurons by stimulating a rapid synthesis and retrograde release of endocannabinoids, which suppress synaptic excitation through presynaptic CB1 receptor activation. The glucocorticoid-induced endocannabinoid synthesis is mediated apparently by a novel membrane-associated glucocorticoid receptor found in multiple subpopulations of hypothalamic neuroendocrine cells. It may, therefore, represent a mechanism for rapid glucocorticoid control of activity among different neuroendocrine systems to coordinate a global response to stress. In support of this, leptin, a circulating adipose signal that regulates food intake and energy expenditure through central actions, blocks the glucocorticoid-mediated endocannabinoid release in the PVN. This represents a means by which the regulation of stress and feeding may interface in the PVN, thus providing a possible mechanism for the integration of multiple homeostatic functions.
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Affiliation(s)
- Jeffrey G Tasker
- Neurobiology Division, Department of Cell and Molecular Biology, Tulane University, 2000 Percival Stern Hall, New Orleans, LA 70118, USA.
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24
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Malcher-Lopes R, Di S, Marcheselli VS, Weng FJ, Stuart CT, Bazan NG, Tasker JG. Opposing crosstalk between leptin and glucocorticoids rapidly modulates synaptic excitation via endocannabinoid release. J Neurosci 2006; 26:6643-50. [PMID: 16775153 PMCID: PMC6674033 DOI: 10.1523/jneurosci.5126-05.2006] [Citation(s) in RCA: 190] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The hypothalamic paraventricular nucleus (PVN) integrates preautonomic and neuroendocrine control of energy homeostasis, fluid balance, and the stress response. We recently demonstrated that glucocorticoids act via a membrane receptor to rapidly cause endocannabinoid-mediated suppression of synaptic excitation in PVN neurosecretory neurons. Leptin, a major signal of nutritional state, suppresses CB(1) cannabinoid receptor-dependent hyperphagia (increased appetite) in fasting animals by reducing hypothalamic levels of endocannabinoids. Here we show that glucocorticoids stimulate endocannabinoid biosynthesis and release via a Galpha(s)-cAMP-protein kinase A-dependent mechanism and that leptin blocks glucocorticoid-induced endocannabinoid biosynthesis and suppression of excitation in the PVN via a phosphodiesterase-3B-mediated reduction in intracellular cAMP levels. We demonstrate this rapid hormonal interaction in both PVN magnocellular and parvocellular neurosecretory cells. Leptin blockade of the glucocorticoid-induced, endocannabinoid-mediated suppression of excitation was absent in leptin receptor-deficient obese Zucker rats. Our findings reveal a novel hormonal crosstalk that rapidly modulates synaptic excitation via endocannabinoid release in the hypothalamus and that provides a nutritional state-sensitive mechanism to integrate the neuroendocrine regulation of energy homeostasis, fluid balance, and the stress response.
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25
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Koroleva SV, Ashmarin IP. A Functional Continuum of Regulatory Anxiety-Enhancing Peptides. The Search for Complexes Providing the Optimal Basis for Developing Inhibitory Therapeutic Agents. ACTA ACUST UNITED AC 2006; 36:157-62. [PMID: 16380829 DOI: 10.1007/s11055-005-0174-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2004] [Indexed: 10/25/2022]
Abstract
Regulatory peptides are actively involved in controlling most physiological processes. One such function is regulation of the level of anxiety and panic states. We report here a meta-analysis of data published from 1960 to 2004 on the effects of anxiety-enhancing regulatory peptides. The resulting database was used to investigate the organization and functioning of the anxiogenic regulatory peptide system. Using vector representation of the effects of these peptides, the spectra of physiological effects which might be provoked by each anxiety- and fear-increasing regulatory peptide alone and in combination were evaluated. Complexes of regulatory peptides with anxiogenic profiles with the greatest potential for the further experimental development of inhibitory pharmacological agents were identified.
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Affiliation(s)
- S V Koroleva
- M. V. Lomonosov Moscow State University, 119899 Moscow, Russia
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26
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Ng YK, Brailoiu GC, Dun SL, Ling EA, Yang J, Chang JK, Dun NJ. Beacon immunoreactivity in the rat hypothalamus. J Neurosci Res 2006; 83:1106-17. [PMID: 16511859 DOI: 10.1002/jnr.20808] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Beacon (BC) is a peptide of 73 amino acids, whose gene expression was first reported in the hypothalamus of Psammomys obesus (or Israeli sand rat). To appreciate better the functional role of BC in normal rats and sand rats, the distribution of BC immunoreactivity (irBC) and its subcellular localization were studied in the brain of Sprague-Dawley rats. In the hypothalamus, intense staining was present in neurons of the supraoptic (SO), paraventricular (PVH), and accessory neurosecretory nuclei and in cell processes of median eminence. Double labeling of the hypothalamic sections with mouse monoclonal oxytocin (OT) antibody and rabbit polyclonal BC antiserum revealed that nearly all OT-immunoreactive cells from SO, PVH, and accessory neurosecretory nuclei were irBC. Double labeling of the sections with guinea pig vasopressin (VP) antiserum and BC antiserum showed that a population of VP-immunoreactive neurons was irBC. By immunoelectron microscopy, immunoreactive product was associated with mitochondrial membranes or appeared as electron-dense bodies in many PVH and SO neurons. Most of the neurosecretory granules were unstained for BC. Taken together, our results indicate the presence of beacon in the OT-containing neurons and a population of VP-containing neurons, mostly associated with mitochondrial membrane. Insofar as the amino acids sequence of beacon is identical to that of ubiquitin-like 5, it is possible that the distribution of BC immunoreactivity noted in our study is that of ubiquitin-like 5 peptide in the rat hypothalamus.
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Affiliation(s)
- Y K Ng
- Department of Anatomy, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
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27
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Guijarro A, Laviano A, Meguid MM. Hypothalamic integration of immune function and metabolism. PROGRESS IN BRAIN RESEARCH 2006; 153:367-405. [PMID: 16876587 PMCID: PMC7119041 DOI: 10.1016/s0079-6123(06)53022-5] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The immune and neuroendocrine systems are closely involved in the regulation of metabolism at peripheral and central hypothalamic levels. In both physiological (meals) and pathological (infections, traumas and tumors) conditions immune cells are activated responding with the release of cytokines and other immune mediators (afferent signals). In the hypothalamus (central integration), cytokines influence metabolism by acting on nucleus involved in feeding and homeostasis regulation leading to the acute phase response (efferent signals) aimed to maintain the body integrity. Peripheral administration of cytokines, inoculation of tumor and induction of infection alter, by means of cytokine action, the normal pattern of food intake affecting meal size and meal number suggesting that cytokines acted differentially on specific hypothalamic neurons. The effect of cytokines-related cancer anorexia is also exerted peripherally. Increase plasma concentrations of insulin and free tryptophan and decrease gastric emptying and d-xylose absorption. In addition, in obesity an increase in interleukin (IL)-1 and IL-6 occurs in mesenteric fat tissue, which together with an increase in corticosterone, is associated with hyperglycemia, dyslipidemias and insulin resistance of obesity-related metabolic syndrome. These changes in circulating nutrients and hormones are sensed by hypothalamic neurons that influence food intake and metabolism. In anorectic tumor-bearing rats, we detected upregulation of IL-1beta and IL-1 receptor mRNA levels in the hypothalamus, a negative correlation between IL-1 concentration in cerebro-spinal fluid and food intake and high levels of hypothalamic serotonin, and these differences disappeared after tumor removal. Moreover, there is an interaction between serotonin and IL-1 in the development of cancer anorexia as well as an increase in hypothalamic dopamine and serotonin production. Immunohistochemical studies have shown a decrease in neuropeptide Y (NPY) and dopamine (DA) and an increase in serotonin concentration in tumor-bearing rats, in first- and second-order hypothalamic nuclei, while tumor resection reverted these changes and normalized food intake, suggesting negative regulation of NPY and DA systems by cytokines during anorexia, probably mediated by serotonin that appears to play a pivotal role in the regulation of food intake in cancer. Among the different forms of therapy, nutritional manipulation of diet in tumor-bearing state has been investigated. Supplementation of tumor bearing rats with omega-3 fatty acid vs. control diet delayed the appearance of tumor, reduced tumor-growth rate and volume, negated onset of anorexia, increased body weight, decreased cytokines production and increased expression of NPY and decreased alpha-melanocyte-stimulating hormone (alpha-MSH) in hypothalamic nuclei. These data suggest that omega-3 fatty acid suppressed pro-inflammatory cytokines production and improved food intake by normalizing hypothalamic food intake-related peptides and point to the possibility of a therapeutic use of these fatty acids. The sum of these data support the concept that immune cell-derived cytokines are closely related with the regulation of metabolism and have both central and peripheral actions, inducing anorexia via hypothalamic anorectic factors, including serotonin and dopamine, and inhibiting NPY leading to a reduction in food intake and body weight, emphasizing the interconnection of the immune and neuroendocrine systems in regulating metabolism during infectious process, cachexia and obesity.
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Affiliation(s)
- Ana Guijarro
- Surgical Metabolism and Nutrition Laboratory, Neuroscience Program, University Hospital, SUNY Upstate Medical University, 750 Adams St., Syracuse, NY 13210, USA
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28
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Fetissov SO, Harro J, Jaanisk M, Järv A, Podar I, Allik J, Nilsson I, Sakthivel P, Lefvert AK, Hökfelt T. Autoantibodies against neuropeptides are associated with psychological traits in eating disorders. Proc Natl Acad Sci U S A 2005; 102:14865-70. [PMID: 16195379 PMCID: PMC1253594 DOI: 10.1073/pnas.0507204102] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Previously, we identified that a majority of patients with anorexia nervosa (AN) and bulimia nervosa (BN) as well as some control subjects display autoantibodies (autoAbs) reacting with alpha-melanocyte-stimulating hormone (alpha-MSH) or adrenocorticotropic hormone, melanocortin peptides involved in appetite control and the stress response. In this work, we studied the relevance of such autoAbs to AN and BN. In addition to previously identified neuropeptide autoAbs, the current study revealed the presence of autoAbs reacting with oxytocin (OT) or vasopressin (VP) in both patients and controls. Analysis of serum levels of identified autoAbs showed an increase of IgM autoAbs against alpha-MSH, OT, and VP as well as of IgG autoAbs against VP in AN patients when compared with BN patients and controls. Further, we investigated whether levels of these autoAbs correlated with psychological traits characteristic for eating disorders. We found significantly altered correlations between alpha-MSH autoAb levels and the total Eating Disorder Inventory-2 score, as well as most of its subscale dimensions in AN and BN patients vs. controls. Remarkably, these correlations were opposite in AN vs. BN patients. In contrast, levels of autoAbs reacting with adrenocorticotropic hormone, OT, or VP had only few altered correlations with the Eating Disorder Inventory-2 subscale dimensions in AN and BN patients. Thus, our data reveal that core psychobehavioral abnormalities characteristic for eating disorders correlate with the levels of autoAbs against alpha-MSH, suggesting that AN and BN may be associated with autoAb-mediated dysfunctions of primarily the melanocortin system.
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Affiliation(s)
- Sergueï O Fetissov
- Department of Neuroscience, Karolinska Institutet, 17177 Stockholm, Sweden.
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Timofeeva E, Baraboi ED, Richard D. Contribution of the vagus nerve and lamina terminalis to brain activation induced by refeeding. Eur J Neurosci 2005; 22:1489-501. [PMID: 16190902 DOI: 10.1111/j.1460-9568.2005.04330.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Following refeeding, c-fos expression is induced in a particular set of brain regions that include the nucleus of the solitary tract (NTS), parabrachial nucleus (PB), central amygdala (CeA), paraventricular hypothalamic nucleus (PVH), supraoptic nucleus (SON) and the circumventricular organs. Within the PVH, the expression is particularly intense in the magnocellular division of the nucleus and it is as yet not clear how this activation occurs. The respective contribution of the vagus afferents and lamina terminalis, which conveys signals entering the brain through the forebrain circumventricular organs, has been investigated in rats subjected to a unilateral cervical vagotomy (UCV) or a unilateral lesion of the fibres running within the lamina terminalis (ULT) and projecting to the neuroendocrine hypothalamus. UCV significantly decreased postprandial c-fos expression in the NTS, PB, CeA and parvocellular division of the PVH. In contrast, ULT impaired postprandial activation of the magnocellular neurons in the PVH and SON. The present study also characterized the types of neurons activated in the PVH and SON during refeeding. In the magnocellular regions, arginine-vasopressin (AVP) neurons were activated upon refeeding whereas there was no apparent induction of Fos expression in oxytocin cells. In the parvocellular PVH, postprandial Fos was induced only in 30% of the corticotrophin-releasing factor (CRF) and AVP neurons. The results of the present study suggest that the postprandial activation of the brain requires the integrity of both the vagal- and lamina terminalis-associated pathways.
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Affiliation(s)
- Elena Timofeeva
- Centre de recherche de l'Hôpital Laval et Centre de recherche sur le métabolisme énergétique de l'Université Laval, Québec, Canada
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Abstract
Animal models have been invaluable for studying aspects of food intake regulation that for various reasons cannot be observed in humans. The dairy cow is a unique animal model because of an unrivaled energy requirement; its great drive to eat results in feeding behavior responses to treatments within the physiological range. Cows' docile nature and large size make them ideal for measuring temporal treatment effects because digestion and absorption kinetics and responses in endocrine systems, gene expression, metabolite pools and fluxes, and feeding behavior can be measured simultaneously. Thus, cows are important models to investigate interactions of short-term signals regulating food intake. Furthermore, different physiological states throughout the lactation cycle provide powerful models to study how short- and long-term signals interact to affect long-term energy status. The use of the cow as a model can lead to breakthroughs in understanding the complex interactions of signals regulating food intake.
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Affiliation(s)
- Michael S Allen
- Department of Animal Science, Michigan State University, East Lansing, Michigan 48824, USA.
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Xu X, Brining DL, Chen JDZ. Effects of vasopressin and long pulse-low frequency gastric electrical stimulation on gastric emptying, gastric and intestinal myoelectrical activity and symptoms in dogs. Neurogastroenterol Motil 2005; 17:236-44. [PMID: 15787943 DOI: 10.1111/j.1365-2982.2004.00616.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The aim of this study was to investigate the effect of vasopressin and long pulse-low frequency gastric electrical stimulation (GES) on gastric emptying, gastric and intestinal myoelectrical activity and symptoms in dogs. The study was performed in eight healthy female dogs implanted with four pairs of gastric serosal electrodes and two pairs of small bowel serosal electrodes, and a duodenal fistula for the assessment of gastric emptying. Each dog was studied in three sessions on three separate days in a randomized order with recordings of gastric and small bowel slow waves. Each study session consisted of 30-min baseline, 30-min stimulation and 30-min recovery period. In sessions 1 and 2, infusion of either saline or vasopressin (0.75 U kg(-1) in 30 mL saline instilled in 30 min) was given during the second 30-min period. The protocol of session 3 was the same as session 2 except long pulse-low frequency GES was performed during the second 30-min period. It was found that: (i) Vasopressin significantly delayed gastric emptying 30 and 45 min after meal and GES did not improve the vasopressin induced delayed gastric emptying; (ii) Vasopressin induced gastric dysrhythmias and GES significantly improved vasopressin induced gastric dysrhythmia; (iii) Vasopressin also induced intestinal slow wave abnormalities but GES had no effect on vasopressin induced small bowel dysrhythmia; (iv) Vasopressin induced symptoms and behaviours suggestive of nausea that were not improved by GES. We conclude that: (i) Vasopressin delays gastric emptying and induces gastric and small bowel dysrhythmias and symptoms in the fed state, and (ii) long pulse-low frequency GES normalizes vasopressin induced gastric dysrhythmia with no improvement in gastric emptying or symptoms.
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Affiliation(s)
- X Xu
- Division of Gastroenterology, University of Texas Medical Branch, Galveston, TX 77555, USA
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Hayes UL, Chambers KC. Peripheral vasopressin accelerates extinction of conditioned taste avoidance. Physiol Behav 2004; 84:147-56. [PMID: 15642618 DOI: 10.1016/j.physbeh.2004.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2003] [Revised: 10/06/2004] [Accepted: 11/08/2004] [Indexed: 10/26/2022]
Abstract
Both peripheral and central administration of vasopressin improves retention and delays extinction when given before or after acquisition of shock avoidance learning. For conditioned taste avoidance, however, vasopressin prolongs extinction when injected peripherally before acquisition tests and accelerates extinction when infused intracerebroventricularly after acquisition. The following experiments were designed to determine whether this inconsistency is based on the route of administration or timing of vasopressin treatment. Because acquisition of conditioned taste avoidance is strengthened when an agent that is capable of inducing avoidance is administered after LiCl injection, it was determined in experiment 1 that a 6 microg/kg dose of vasopressin did not induce conditioned taste avoidance when administered 50 min after consumption of a sucrose solution. In experiment 2, it was determined that this dose of vasopressin accelerated extinction of a LiCl-induced conditioned taste avoidance when given 50 min after LiCl injection. These results suggest that the inconsistency is not based on route of administration. In experiment 3, it was determined that there was a tendency for animals to show prolonged extinction when vasopressin was administered 20 min before access to a sucrose solution. All of the results taken together suggest that the differential effects of vasopressin on extinction are due to the timing of administration. It was suggested that vasopressin accelerates extinction when given after acquisition by reducing the effectiveness of LiCl and it prolongs extinction when given before acquisition by altering neural responsiveness in areas mediating conditioned taste avoidance.
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Affiliation(s)
- UnJa L Hayes
- Center for Neuroendocrine Studies, University of Massachusetts, Tobin Hall, Amherst, MA 01003, USA.
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Bachner-Melman R, Zohar AH, Elizur Y, Nemanov L, Gritsenko I, Konis D, Ebstein RP. Association between a vasopressin receptor AVPR1A promoter region microsatellite and eating behavior measured by a self-report questionnaire (Eating Attitudes Test) in a family-based study of a nonclinical population. Int J Eat Disord 2004; 36:451-60. [PMID: 15558634 DOI: 10.1002/eat.20049] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
OBJECTIVES Considerable evidence including twin and family studies suggests that biologic determinants interact with cultural cues in the etiology of anorexia and bulimia nervosa. A gene that makes "biologic sense" in contributing susceptibility to these disorders, and to our knowledge not previously investigated for this phenotype, is the vasopressin receptor (AVPR1A), which we have tested for association with eating pathology. METHODS We genotyped 280 families with same-sex siblings for two microsatellites in the promoter region of the AVPR1A gene. Siblings completed the 26-item Eating Attitudes Test (EAT) and the Drive for Thinness (DT) and Body Dissatisfaction (BD) subscales of the Eating Disorders Inventory (EDI). The Quantitative Transmission Disequilibrium Test program (QTDT), which employs flexible and powerful variance-components procedures, was used to test for an association between EAT scores and the two AVPR1A promoter region microsatellites, RS1 and RS3. RESULTS A significant association (p = .036) was detected between the RS3 microsatellite and EAT scores. The strongest association was between RS3 and the Dieting subscale of the EAT (p = .011). A significant association was also observed between the EDI-DT and the RS3 microsatellit (p = .0450). CONCLUSIONS We demonstrate for the first time an association between a microsatellite polymorphism in the AVPR1A promoter region and scores on the EAT as well as with the EDI-DT. The strongest association was observed between the RS3 microsatellite and the Dieting subscale of the EAT. The relevant phenotype appears to tap severe dietary restriction for weight loss purposes.
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Ikemura R, Matsuwaki T, Yamanouchi K, Nishihara M. Involvement of endogenous vasopressin in high plasma osmolality-induced anorexia via V1 receptor-mediated mechanism. J Vet Med Sci 2004; 66:951-5. [PMID: 15353846 DOI: 10.1292/jvms.66.951] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
It is known that water deprivation or injection of hypertonic saline induces anorexia. The present study examined the possible involvement of vasopressin in the suppression of food intake during high plasma osmolality. Intraperitoneal injection of vasopressin (20 microg/kg) into male rats significantly suppressed food intake for 1 hr. This anorectic effect of vasopressin was reversed by simultaneous injection of a peptide antagonist for V(1) receptor (40 microg/kg), but not for V(2) receptor (40 microg/kg). Intraperitoneal injection of hypertonic saline (20% NaCl, 2 ml/kg) similarly suppressed food intake for 2 hr, which was associated with a transient increase in plasma vasopressin concentrations. This hypertonic saline-induced suppression of food intake was blocked by a V(1) receptor antagonist. Vasopressin (40 ng/2 microl) directly administered into the third ventricle of the brain also suppressed food intake for 1 hr. These results suggest that vasopressin participates in the suppression of food intake during high plasma osmolality, the action of which is mediated by V(1) receptors in the brain.
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Affiliation(s)
- Ryota Ikemura
- Department of Veterinary Physiology, Veterinary Medical Science, The University of Tokyo, Japan
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Brailoiu GC, Dun SL, Chi M, Ohsawa M, Chang JK, Yang J, Dun NJ. Beacon/ubiquitin-like 5-immunoreactivity in the hypothalamus and pituitary of the mouse. Brain Res 2003; 984:215-23. [PMID: 12932856 DOI: 10.1016/s0006-8993(03)03161-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Beacon is a 73-amino acid peptide encoded by a novel gene in the hypothalamus of Israeli sand rat Psammomys obesus. Reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemical techniques were used to investigate the presence of beacon mRNA and the distribution of beacon-immunoreactivity (irBC) in the hypothalamus of ICR mice. RT-PCR experiments revealed beacon mRNA in the mouse hypothalamus. Using a rabbit polyclonal antiserum directed against the synthetic C-terminal peptide fragment (47-73), irBC was detected in the mouse hypothalamus and pituitary. In the hypothalamus, irBC was concentrated in perikarya of the supraoptic (SO), paraventricular (PVH) and accessory neurosecretory nuclei and in cell processes of the median eminence and pituitary stalk. In the pituitary, irBC was noted mainly in the posterior lobe. Double-labeling the hypothalamic sections with guinea-pig vasopressin-antiserum or mouse monoclonal oxytocin-antibody and beacon-antiserum revealed that <30% of vasopressin-immunoreactive neurons and nearly all oxytocin-immunoreactive neurons in the PVH and SO were irBC. The result shows the presence of beacon mRNA in the mouse hypothalamus, and the distribution of irBC is distinctively different from that reported in the hypothalamus of Psammomys obesus, but similar to that of the Sprague-Dawley rats described in our earlier study. More interestingly, Blast search uncovered a 73-amino acid peptide, human ubiquitin-like 5, which has the same exact sequence as beacon. Thus, irBC observed in the mouse brain could be that of ubiquitin-like 5.
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Affiliation(s)
- G Cristina Brailoiu
- Department of Pharmacology, James H. Quillen College of Medicine, East Tennessee State University, P.O. Box 70577, Johnson City, TN 37614, USA.
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Olszewski PK, Wirth MM, Shaw TJ, Grace MK, Levine AS. Peptides that regulate food intake: effect of peptide histidine isoleucine on consummatory behavior in rats. Am J Physiol Regul Integr Comp Physiol 2003; 284:R1445-53. [PMID: 12595279 DOI: 10.1152/ajpregu.00554.2002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Peptide histidine isoleucine (PHI) and VIP are derived from the same precursor. While central VIP decreases food intake, potential effects of PHI on feeding have not been studied. In the current study, we found that PHI administered intracerebroventricularly (ICV) or into the hypothalamic paraventricular nucleus (PVN) or central nucleus of the amygdala (CeA) decreased food consumption in overnight-deprived rats. The magnitude of an anorexigenic response to PHI differed depending on the injection route: ICV-infused peptide evoked the most potent effect. We determined that that only PVN- and CeA-injected PHI did not have aversive consequences. In addition, we infused anorexigenic doses of PHI via the same routes and assessed Fos immunoreactivity of PVN oxytocin (OT) and vasopressin (VP) neurons using double immunohistochemistry. OT and VP are thought to promote feeding termination. PHI increased the percentage of Fos-positive OT neurons regardless of the injection route. PVN- and ICV-infused PHI induced activation of VP cells. We conclude that central PHI has an inhibitory influence on food intake in rats. The PVN, with OT and VP neurons, and CeA may be involved in the mediation of anorexigenic effects of PHI.
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Affiliation(s)
- Pawel K Olszewski
- Veterans Affairs Medical Center, Research Service, Minneapolis 55417, USA.
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Abstract
The high incidence of obesity, its multifactorial nature, the complexity and lack of knowledge of the bodyweight control system, and the scarcity of adequate therapeutics have fuelled anti-obesity drug development during a considerable number of years. Irrespective of the efforts invested by researchers and companies, few products have reached a minimum level of effectiveness, and even fewer are available in medical practice. As a consequence of anti-obesity research, our knowledge of the bodyweight control system increased but, despite this, the pharmacological approaches to the treatment of obesity have not resulted yet in effective drugs. This review provides a panoramic of the multiple different approaches developed to obtain workable drugs. These approaches, however, rely in only four main lines of action: control of energy intake, mainly through modification of appetite;control of energy expenditure, essentially through the increase of thermogenesis;control of the availability of substrates to cells and tissues through hormonal and other metabolic factors controlling the fate of the available energy substrates; andcontrol of fat reserves through modulation of lipogenesis and lipolysis in white adipose tissue. A large proportion of current research is centred on neuropeptidic control of appetite, followed by the development of drugs controlling thermogenic mechanisms and analysis of the factors controlling adipocyte growth and fat storage. The adipocyte is also a fundamental source of metabolic signals, signals that can be intercepted, modulated and used to force the brain to adjust the mass of fat with the physiological means available. The large variety of different approaches used in the search for effective anti-obesity drugs show both the deep involvement of researchers on this field and the large amount of resources devoted to this problem by pharmaceutical companies. Future trends in anti-obesity drug research follow closely the approaches outlined; however, the increasing mass of information on the molecular basis of bodyweight control and obesity will in the end prevail in our search for effective and harmless anti-obesity drugs.
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Affiliation(s)
- José-Antonio Fernández-López
- Centre Especial de Recerca en Nutrició i Ciència dels Aliments, Facultat de Biologia, Universitat de Barcelona, Barcelona, Spain
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Koroleva SV, Ashmarin IP. Functional continuum of regulatory peptides (RPs): vector model of RP-effects representation. J Theor Biol 2002; 216:257-71. [PMID: 12183118 DOI: 10.1006/jtbi.2002.2555] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
During the past decades, bioactive (regulatory) peptides have been identified as the major players in the regulation of many important biological processes. Dozens of peptides have found their application as pharmaceutical agents, which further stimulated research in this field making it one of the most rapidly developing areas on the edge of biological science and medicine. However, the fast accumulation of enormous amounts of experimental data has revealed a great difficulty in their analysis and demanded the development of a systematic approach for generalization of the obtained information. We propose a new computer-based algorithm for studying biological activities of regulatory peptides and their groups based on their representation as vectors in n -dimensional functional space. Our method allows the rapid analysis of databases containing thousands of polyfunctional regulatory peptides with overlapping spectra of physiological activity. The described method permits to perform several types of correlations which, when applied to the large databases, could reveal new important information about the system of regulatory peptides. It can select the groups of peptides with similar physiological role (peptide constellations) and search for the optimal peptide combinations with predetermined spectrum of effects and minimal side effects for their further pharmacological application. It can also reveal the role of regulatory peptides in induction of chain physiological reactions.
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Affiliation(s)
- S V Koroleva
- Department of Biology, Moscow State University, Vorobievy Gory, Moscow, 119899, Russia.
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Abstract
Esta revisão apresenta informações a respeito de substâncias fisiológicas que afetam a homeostase energética. Os autores fizeram uma extensa revisão em relação aos mecanismos fisiológicos que modulam o balanço energético quando administrados central ou perifericamente (por exemplo, nutrientes, monoaminas e peptídeos).
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40
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Bray GA, York DA. Obesity. Compr Physiol 2001. [DOI: 10.1002/cphy.cp070234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Sato T, Fetissov SO, Meguid MM, Miyata G, Chen C. Intra-supraoptic nucleus sulpiride improves anorexia in tumor-bearing rats. Neuroreport 2001; 12:2429-32. [PMID: 11496123 DOI: 10.1097/00001756-200108080-00028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Previous studies suggest that the dopaminergic system in the supraoptic nucleus (SON) is involved not only in the water balance control but also in the food intake regulation. Since we reported that an injection of the D2 receptor antagonist, sulpiride, into specific hypothalamic nuclei (e.g. the LHA, or the VMN) increases food intake in anorectic tumor-bearing rats, as well as in normal rats, we hypothesized that an injection of sulpiride into the SON would also improve cancer anorexia. Sulpiride injection (4 microg/0.5 microl) into bilateral SON of anorectic tumor-bearing male rats significantly improved food intake via increases in both meal size and meal number. These data suggest that pharmacological manipulation of the hypothalamic dopaminergic system is feasible in amelioration of cancer anorexia.
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Affiliation(s)
- T Sato
- Neuroscience Program, Surgical Metabolism and Nutrition Laboratory, Department of Surgery, University Hospital, SUNY Upstate Medical University, 750 East Adams Street, Syracuse, NY 13210, USA
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Olszewski PK, Wirth MM, Shaw TJ, Grace MK, Billington CJ, Giraudo SQ, Levine AS. Role of alpha-MSH in the regulation of consummatory behavior: immunohistochemical evidence. Am J Physiol Regul Integr Comp Physiol 2001; 281:R673-80. [PMID: 11448874 DOI: 10.1152/ajpregu.2001.281.2.r673] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Central injection of alpha-melanocyte-stimulating hormone (alpha-MSH) decreases food intake, suggesting a role for this peptide in the mediation of satiety. Inasmuch as alpha-MSH also supports the development of taste aversions under certain conditions, the nature of its influence on ingestive behavior, i.e., whether it is related to satiety or aversion, remains unclear. In the present studies, we used immunostaining, including that for c-Fos as a marker of neuronal activation, to further substantiate the physiological role for alpha-MSH in the regulation of consummatory behavior. We found that an increase in activation of alpha-MSH neurons in the arcuate nucleus coincided with meal termination. Administration of powerful aversive agents, LiCl and CuSO(4), did not stimulate alpha-MSH cells but did induce pronounced activation of oxytocin (OT) and vasopressin (VP) neurons, the final components of circuitry mediating aversion. We observed fewer Fos-positive OT/VP neurons after alpha-MSH injection into the lateral ventricle or into the hypothalamic paraventricular nucleus, treatments that cause mild or no aversion, respectively. The degree of activation of OT/VP neurons paralleled the magnitude of aversive response to a given treatment. Our data support the hypothesis that, in the arcuate nucleus, alpha-MSH acts as a satiety mediator independent from aversion-related mechanisms.
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Affiliation(s)
- P K Olszewski
- Minnesota Obesity Center, Research Service, Veterans Affairs Medical Center, One Veterans Drive, Minneapolis, MN 55417, USA
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Ritter S, Bugarith K, Dinh TT. Immunotoxic destruction of distinct catecholamine subgroups produces selective impairment of glucoregulatory responses and neuronal activation. J Comp Neurol 2001; 432:197-216. [PMID: 11241386 DOI: 10.1002/cne.1097] [Citation(s) in RCA: 198] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The toxin-antibody complex anti-d(beta)h-saporin (DSAP) selectively destroys d(beta)h-containing catecholamine neurons. To test the role of specific catecholamine neurons in glucoregulatory feeding and adrenal medullary secretion, we injected DSAP, unconjugated saporin (SAP), or saline bilaterally into the paraventricular nucleus of the hypothalamus (PVH) or spinal cord (T2-T4) and subsequently tested rats for 2-deoxy-D-glucose (2DG)-induced feeding and blood glucose responses. Injections of DSAP into the PVH abolished 2DG-induced feeding, but not hyperglycemia. 2DG-induced Fos expression was profoundly reduced or abolished in the PVH, but not in the adrenal medulla. The PVH DSAP injections caused a nearly complete loss of tyrosine hydroxylase immunoreactive (TH-ir) neurons in the area of A1/C1 overlap and severe reduction of A2, C2, C3 (primarily the periventricular portion), and A6 cell groups. Spinal cord DSAP blocked 2DG-induced hyperglycemia but not feeding. 2DG-induced Fos-ir was abolished in the adrenal medulla but not in the PVH. Spinal cord DSAP caused a nearly complete loss of TH-ir in cell groups A5, A7, subcoeruleus, and retrofacial C1 and a partial destruction of C3 (primarily the ventral portion) and A6. Saline and SAP control injections did not cause deficits in 2DG-induced feeding, hyperglycemia, or Fos expression and did not damage catecholamine neurons. DSAP eliminated d(beta)h immunoreactivity but did not cause significant nonspecific damage at injection sites. The results demonstrate that hindbrain catecholamine neurons are essential components of the circuitry for glucoprivic control of feeding and adrenal medullary secretion and indicate that these responses are mediated by different subpopulations of catecholamine neurons.
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Affiliation(s)
- S Ritter
- Programs in Neuroscience, Washington State University, Pullman, WA 99164-6520, USA.
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Olszewski PK, Shi Q, Billington CJ, Levine AS. Opioids affect acquisition of LiCl-induced conditioned taste aversion: involvement of OT and VP systems. Am J Physiol Regul Integr Comp Physiol 2000; 279:R1504-11. [PMID: 11004021 DOI: 10.1152/ajpregu.2000.279.4.r1504] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Aversive properties of lithium chloride (LiCl) are mediated via pathways comprising neurons of the nucleus of the solitary tract (NTS) and oxytocin (OT) and vasopressin (VP) cells in the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei. Because opioids act on brain regions that mediate effects of LiCl, we evaluated whether administration of opioids shortly before LiCl in rats influences 1) development of conditioned taste aversion (CTA) and 2) activation of NTS neurons and OT/VP cells. Neuronal activation was assessed by applying c-Fos immunohistochemical staining. Three opioids were used: morphine (MOR), a mu-agonist, butorphanol tartrate (BT), a mixed mu/kappa-agonist, and nociceptin/orphanin FQ (N/OFQ), which binds to an ORL1 receptor. BT and N/OFQ completely blocked acquisition of CTA. MOR alleviated but did not eliminate the aversive effects. Each of the opioids decreased LiCl-induced activation of NTS neurons as well as OT and VP cells in the PVN and SON. We conclude that opioids antagonize aversive properties of LiCl, presumably by suppressing activation of pathways that encompass OT and VP cells and NTS neurons.
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Affiliation(s)
- P K Olszewski
- Minnesota Obesity Center, Research Service Veterans Affairs Medical Center, Minneapolis 55417, USA
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Abstract
Food intake is a regulated system. Afferent signals provide information to the central nervous system, which is the centre for the control of satiety or food seeking. Such signals can begin even before food is ingested through visual, auditory and olfactory stimuli. One of the recent interesting findings is the demonstration that there are selective fatty acid taste receptors on the tongue of rodents. The suppression of food intake by essential fatty acids infused into the stomach and the suppression of electrical signals in taste buds reflect activation of a K rectifier channel (K 1.5). In animals that become fat eating a high-fat diet the suppression of this current by linoleic acid is less than that in animals that are resistant to obesity induced by dietary fat. Inhibition of fatty acid oxidation with either mercaptoacetate (which blocks acetyl-CoA dehydrogenase) or methylpalmoxirate will increase food intake. When animals have a choice of food, mercaptoacetate stimulates the intake of protein and carbohydrate, but not fat. Afferent gut signals also signal satiety. The first of these gut signals to be identified was cholecystokinin (CCK). When CCK acts on CCK-A receptors in the gastrointestinal tract, food intake is suppressed. These signals are transmitted by the vagus nerve to the nucleus tractus solitarius and thence to higher centres including the lateral parabrachial nucleus, amygdala, and other sites. Rats that lack the CCK-A receptor become obese, but transgenic mice lacking CCK-A receptors do not become obese. CCK inhibits food intake in human subjects. Enterostatin, the pentapeptide produced when pancreatic colipase is cleaved in the gut, has been shown to reduce food intake. This peptide differs in its action from CCK by selectively reducing fat intake. Enterostatin reduces hunger ratings in human subjects. Bombesin and its human analogue, gastrin inhibitory peptide (also gastrin-insulin peptide), reduce food intake in obese and lean subjects. Animals lacking bombesin-3 receptor become obese, suggesting that this peptide may also be important. Circulating glucose concentrations show a dip before the onset of most meals in human subjects and rodents. When the glucose dip is prevented, the next meal is delayed. The dip in glucose is preceded by a rise in insulin, and stimulating insulin release will decrease circulating glucose and lead to food intake. Pyruvate and lactate inhibit food intake differently in animals that become obese compared with lean animals. Leptin released from fat cells is an important peripheral signal from fat stores which modulates food intake. Leptin deficiency or leptin receptor defects produce massive obesity. This peptide signals a variety of central mechanisms by acting on receptors in the arcuate nucleus and hypothalamus. Pancreatic hormones including glucagon, amylin and pancreatic polypeptide reduce food intake. Four pituitary peptides also modify food intake. Vasopressin decreases feeding. In contrast, injections of desacetyl melanocyte-stimulating hormone, growth hormone and prolactin are associated with increased food intake. Finally, there are a group of miscellaneous peptides that modulate feeding. beta-Casomorphin, a heptapeptide produced during the hydrolysis of casein, stimulates food intake in experimental animals. In contrast, the other peptides in this group, including calcitonin, apolipoprotein A-IV, the cyclized form of histidyl-proline, several cytokines and thyrotropin-releasing hormone, all decrease food intake. Many of these peptides act on gastrointestinal or hepatic receptors that relay messages to the brain via the afferent vagus nerve. As a group they provide a number of leads for potential drug development.
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Affiliation(s)
- G A Bray
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge 70808, USA.
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46
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Abstract
Nocistatin, a product of the same precursor as nociceptin/orphanin FQ (N/OFQ), has been shown to antagonize effects of N/OFQ. N/OFQ stimulates feeding, most probably by inhibiting activation of neurons containing oxytocin (OT) and vasopressin (VP), peptides considered as satiety factors, and implicated in the development of conditioned taste aversion (CTA). The present study was designed to investigate whether intracerebroventricularly (ICV) injected nocistatin (a) affects deprivation- and N/OFQ-induced feeding, (b) causes CTA, and (c) induces activation of hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei, as well as OT and VP neurons present in these regions. C-Fos immunohistochemistry was used as a marker of cellular activation. Nocistatin (1-3 nmol) significantly reduced food intake in deprived rats during the first and second hour post-injection. Doses of 1-3 nmol suppressed N/OFQ-induced feeding. Nocistatin at the highest (3 nmol) dose did not cause CTA. It also did not affect activation of the PVN or SON. In nocistatin-treated animals, the percentage of Fos-positive OT and VP neurons was similar to controls. We conclude that nocistatin antagonizes the influence of N/OFQ on feeding and suppresses deprivation-induced food consumption through mechanisms other than aversion. Nocistatin does not, however, activate the PVN or SON. It does not exert its effects via VP or OT neurons.
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Affiliation(s)
- P K Olszewski
- Minnesota Obesity Center, Research Service 151, Veterans Affairs Medical Center, One Veterans Drive, Minneapolis, MN 55417, USA
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Affiliation(s)
- G A Bray
- Louisiana State University, Pennington Biomedical Research Center, Baton Rouge 70808-4124, USA
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Méchaly I, Krosniak M, Azay J, Cassanas G, Roque C, Cahard D, Serrano JJ, Cros G. Interactive computerized microscopy as a tool for quantifying vascular remodelling effects of diabetes and V1a receptor antagonist SR 49059 on rat mesenteric arterial bed. J Pharmacol Toxicol Methods 1999; 41:59-67. [PMID: 10598676 DOI: 10.1016/s1056-8719(99)00021-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A methodology using interactive computerized microscopy (ICM) was developed to quantify in the mesenteric arterial bed the morphometric changes associated with diabetes and the influence of treatment with SR 49059, an antagonist of vasopressin V1a receptors. Four groups of rats were studied: untreated normal (N) or streptozotocin- (60 mg/kg i.v.) induced diabetic (D), and treated (0.4 mg/g SR 49059 included in food) normal (NT) or diabetic (DT) animals. Treatment was initiated 4 days after diabetes induction and continued for 3 weeks. Nested (hierarchical) analysis of variance of ICM data was performed on raw diameter or after logarithmic normalization of area and nuclei values. Diabetes was associated with an increase in arterial diameters, and in total vessel, wall, media, adventitia, and lumen areas. The same parameters, with the exception of the lumen, were also increased in DT as compared to D. The number of nuclei in the media or adventitia was increased in D as compared to N, and in DT as compared to D. In summary, ICM is allowed to further characterize the vascular mesenteric changes and describe for the first time the enlargement of adventitia associated with diabetes. Our study also suggested that the blockade of Via receptors is unable to prevent diabetes-related vascular changes, although the slight increase in food intake associated with SR 49059 treatment may have had an indirect influence on angiopathy development.
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Affiliation(s)
- I Méchaly
- Laboratoire de Pharmacologie et Physiopathologie Expérimentales, Faculté de Pharmacie, Montpellier, France
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Gorbatyuk O, Hökfelt T. Effect of inhibition of glucose and fat metabolism on galanin-R1 receptor mRNA levels in the rat hypothalamic paraventricular and supraoptic nuclei. Neuroreport 1998; 9:3565-9. [PMID: 9858361 DOI: 10.1097/00001756-199811160-00005] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Using in situ hybridization histochemistry we have studied the effect of glucose and fat deprivation on galanin-R1 receptor (GAL-R1-R) mRNA levels in the rat paraventricular (PVN) and supraoptic (SON) nuclei after single and repeated i.p. administration of a glucose antimetabolite 2-deoxy-D-glucose (DG), as well as of a fatty acid antimetabolite, sodium mercaptoacetate (MA), treatments known to increase food intake. Both DG and MA injections caused an increase in levels of GAL-R1 mRNA transcripts in the PVN and SON. These results indicate that glucose and fat deprivation increase the sensitivity of PVN and SON neurons to galanin, and that regulation of receptor levels may be an important mechanism in galaninergic signalling.
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Affiliation(s)
- O Gorbatyuk
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
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