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Balbo SL, Ribeiro RA, Mendes MC, Lubaczeuski C, Maller ACPA, Carneiro EM, Bonfleur ML. Vagotomy diminishes obesity in cafeteria rats by decreasing cholinergic potentiation of insulin release. J Physiol Biochem 2016; 72:625-633. [PMID: 27351887 DOI: 10.1007/s13105-016-0501-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 06/21/2016] [Indexed: 01/06/2023]
Abstract
Herein, we investigated whether subdiaphragmatic vagotomy has benefits on obesity, body glucose homeostasis, and insulin secretion in cafeteria (CAF)-obese rats. Wistar rats were fed a standard or CAF diet for 12 weeks. Subsequently, CAF rats were randomly submitted to truncal vagotomy (CAF Vag) or sham operation (CAF Sham). CAF Sham rats were hyperphagic, obese, and presented metabolic disturbances, including hyperinsulinemia, glucose intolerance, insulin resistance, hyperglycemia, and hypertriglyceridemia. Twelve weeks after vagotomy, CAF Vag rats presented reductions in body weight and perigonadal fat stores. Vagotomy did not modify glucose tolerance but normalized fed glycemia, insulinemia, and insulin sensitivity. Isolated islets from CAF Sham rats secreted more insulin in response to the cholinergic agent, carbachol, and when intracellular cyclic adenine monophosphate (cAMP) is enhanced by forskolin or 3-isobutyl-1-methylxanthine. Vagotomy decreased glucose-induced insulin release due to a reduction in the cholinergic action on β-cells. This effect also normalized islet secretion in response to cAMP. Therefore, vagotomy in rats fed on a CAF-style diet effectively decreases adiposity and restores insulin sensitivity. These effects were mainly associated with the lack of cholinergic action on the endocrine pancreas, which decreases insulinemia and may gradually reduce fat storage and improve insulin sensitivity.
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Affiliation(s)
- Sandra Lucinei Balbo
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, UNIOESTE, Cascavel, PR, 858119-110, Brazil
| | | | - Mariana Carla Mendes
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, UNIOESTE, Cascavel, PR, 858119-110, Brazil
| | - Camila Lubaczeuski
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, UNIOESTE, Cascavel, PR, 858119-110, Brazil
| | - Ana Claudia Paiva Alegre Maller
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, UNIOESTE, Cascavel, PR, 858119-110, Brazil
| | - Everardo Magalhães Carneiro
- Laboratório de Pâncreas Endócrino e Metabolismo, Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, UNICAMP, Campinas, SP, Brazil
| | - Maria Lúcia Bonfleur
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, UNIOESTE, Cascavel, PR, 858119-110, Brazil.
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Lubaczeuski C, Balbo SL, Ribeiro RA, Vettorazzi JF, Santos-Silva JC, Carneiro EM, Bonfleur ML. Vagotomy ameliorates islet morphofunction and body metabolic homeostasis in MSG-obese rats. ACTA ACUST UNITED AC 2015; 48:447-57. [PMID: 25714886 PMCID: PMC4445669 DOI: 10.1590/1414-431x20144340] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 11/17/2014] [Indexed: 01/11/2023]
Abstract
The parasympathetic nervous system is important for β-cell secretion and mass
regulation. Here, we characterized involvement of the vagus nerve in pancreatic
β-cell morphofunctional regulation and body nutrient homeostasis in 90-day-old
monosodium glutamate (MSG)-obese rats. Male newborn Wistar rats received MSG (4 g/kg
body weight) or saline [control (CTL) group] during the first 5 days of life. At 30
days of age, both groups of rats were submitted to sham-surgery (CTL and MSG groups)
or subdiaphragmatic vagotomy (Cvag and Mvag groups). The 90-day-old MSG rats
presented obesity, hyperinsulinemia, insulin resistance, and hypertriglyceridemia.
Their pancreatic islets hypersecreted insulin in response to glucose but did not
increase insulin release upon carbachol (Cch) stimulus, despite a higher
intracellular Ca2+ mobilization. Furthermore, while the pancreas weight
was 34% lower in MSG rats, no alteration in islet and β-cell mass was observed.
However, in the MSG pancreas, increases of 51% and 55% were observed in the total
islet and β-cell area/pancreas section, respectively. Also, the β-cell number per
β-cell area was 19% higher in MSG rat pancreas than in CTL pancreas. Vagotomy
prevented obesity, reducing 25% of body fat stores and ameliorated glucose
homeostasis in Mvag rats. Mvag islets demonstrated partially reduced insulin
secretion in response to 11.1 mM glucose and presented normalization of Cch-induced
Ca2+ mobilization and insulin release. All morphometric parameters were
similar among Mvag and CTL rat pancreases. Therefore, the higher insulin release in
MSG rats was associated with greater β-cell/islet numbers and not due to hypertrophy.
Vagotomy improved whole body nutrient homeostasis and endocrine pancreatic
morphofunction in Mvag rats.
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Affiliation(s)
- C Lubaczeuski
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná, Cascavel, PR, Brasil
| | - S L Balbo
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná, Cascavel, PR, Brasil
| | - R A Ribeiro
- Universidade Federal do Rio de Janeiro, Macaé, RJ, Brasil
| | - J F Vettorazzi
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, Brasil
| | - J C Santos-Silva
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, Brasil
| | - E M Carneiro
- Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, SP, Brasil
| | - M L Bonfleur
- Laboratório de Fisiologia Endócrina e Metabolismo, Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná, Cascavel, PR, Brasil
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Kreier F, Kalsbeek A, Ruiter M, Yilmaz A, Romijn JA, Sauerwein HP, Fliers E, Buijs RM. Central nervous determination of food storage—a daily switch from conservation to expenditure: implications for the metabolic syndrome. Eur J Pharmacol 2003; 480:51-65. [PMID: 14623350 DOI: 10.1016/j.ejphar.2003.08.092] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Here, we present a neuroendocrine concept to review the circularly interacting energy homeostasis system between brain and body. Body-brain interaction is circular because the brain immediately integrates an input to an output, and because part of this response may be that the brain modulates the sensitivity of this perception. First, we describe how the brain senses the body through neurons and blood-borne factors. Direct neuronal connections report the state of various organs. In addition, humoral factors are perceived by the blood-brain barrier and circumventricular organs. We describe how circulating energy carriers are sensed and what signals reach the brain during food intake, exercise and an immune response. We describe that the brain regulates the homeostatic process at two fundamentally different levels during the active and inactive states. The unbalanced output of the brain in the metabolic syndrome is discussed in relation with such circadian rhythms and with regional activity of the autonomic nervous system. In line with the above, we suggest a new approach for the diagnosis and therapy of the metabolic syndrome.
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Affiliation(s)
- Felix Kreier
- Netherlands Institute for Brain Research, 1105 AZ, Amsterdam, The Netherlands.
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Abstract
In female mammals reproduction is highly sensitive to the food supply. During lean times, females suspend reproductive attempts in favor of maintaining processes necessary for survival; fertility is restored once the food supply is again abundant. Nearly all aspects of reproduction are affected, including puberty, adult ovulatory cycles, and reproductive behaviors. Work with experimental animals reveals that caloric restriction inhibits release of luteinizing hormone (LH) and female sexual behavior via similar, although separate, processes. The primary metabolic event affecting LH release as well as female sexual behavior is the short-term (minute-to-minute, hour-to-hour) availability of oxidizable metabolic fuels, rather than any aspect of body size or composition (e.g., body fat content). Metabolic fuel availability is detected in the hindbrain and perhaps in peripheral tissues. Metabolic information is then transmitted synaptically from the visceral hindbrain to the forebrain effector circuits. In the forebrain, signaling via corticotropin-releasing hormone receptors appears to be crucial for inhibition of both LH secretion and female sexual behavior.
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Affiliation(s)
- George N Wade
- Center for Neuroendocrine Studies, University of Massachusetts, Amherst, MA 01003, USA.
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Kalsbeek A, Strubbe JH. Circadian control of insulin secretion is independent of the temporal distribution of feeding. Physiol Behav 1998; 63:553-8. [PMID: 9523898 DOI: 10.1016/s0031-9384(97)00493-9] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
To investigate whether there is a circadian regulation of insulin secretion, rats were adapted to a feeding regimen of six meals equally distributed over 24 h. Under these conditions basal glucose and insulin levels increased during the light phase and decreased during the dark phase. Maximal blood glucose responses were fairly similar during the six different meals, but glucose increments were clearly delayed during the last two meals consumed during the light period. Insulin increments were highest during the dark phase and clearly diminished during the second half of the light phase. This situation was reversed when the scheduled meals were replaced by i.v. glucose infusions, i.e., no significant differences were detected between insulin responses, whereas glucose increments were reduced during the dark period. These results show that there is a circadian regulation of basal blood glucose and feeding-induced insulin responses, which is independent of the temporal distribution of feeding activity.
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Affiliation(s)
- A Kalsbeek
- Netherlands Institute for Brain Research, Amsterdam.
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Abstract
Although it has been known for many years that the liver receives a nerve supply, it is only with the advent of immunohistochemistry that this innervation has been analysed in depth. It is now appreciated not only that many different nerve types are present, but also that there are significant differences between species, especially in the degree of parenchymal innervation. This has stimulated more detailed investigation of the innervation of the human liver in both health and disease. At the same time, functional studies have been underlining the important roles that these nerves play in processes as diverse as osmoreception and liver regeneration. This article briefly reviews current understanding of the morphology and functions of the hepatic nerve supply.
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Affiliation(s)
- D G Tiniakos
- Department of Pathology, University of Patras, Greece
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Cincotta AH, Meier AH. Bromocriptine inhibits in vivo free fatty acid oxidation and hepatic glucose output in seasonally obese hamsters (Mesocricetus auratus). Metabolism 1995; 44:1349-55. [PMID: 7476296 DOI: 10.1016/0026-0495(95)90041-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Seasonally obese hyperinsulinemic hamsters were treated for 5 weeks with bromocriptine (500 to 600 micrograms per animal) and tested for drug effects on energy balance, body fat stores, nocturnal whole-body free fatty acid (FFA) metabolism and hepatic glucose output, and diurnal glucose tolerance. After 5 weeks, bromocriptine treatment reduced retroperitoneal fat pad weight by 45% without altering either daily food consumption or end-treatment total daily energy expenditure. Also, 5 weeks of treatment improved the diurnal glucose tolerance, resulting in a 47% and 33% decrease in the area under glucose and insulin curves, respectively. After 4 weeks, bromocriptine treatment reduced nocturnal lipolysis by 28%, palmitate rate of appearance into plasma by 30%, palmitate oxidation by 33%, and hepatic glucose output by 28%. Moreover, these reductions were accompanied by a 75% reduction in plasma insulin concentration. The data suggest that bromocriptine may improve diurnal glucose tolerance in part by inhibiting the preceding nocturnal lipolysis and FFA oxidation. Reductions in nocturnal FFA oxidation and hepatic glucose production may result from bromocriptine's influences on circadian organization of hypothalamic centers known to regulate these activities. Available evidence suggests that bromocriptine may impact this neuroendocrine organization of metabolism by increasing the dopamine to noradrenaline activity ratio in central (hypothalamic) and peripheral (eg, liver and adipose) target tissues.
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Affiliation(s)
- A H Cincotta
- Wellman Laboratories of Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, Boston, USA
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Cincotta AH, Schiller BC, Landry RJ, Herbert SJ, Miers WR, Meier AH. Circadian neuroendocrine role in age-related changes in body fat stores and insulin sensitivity of the male Sprague-Dawley rat. Chronobiol Int 1993; 10:244-58. [PMID: 8403068 DOI: 10.1080/07420529309059707] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A role for circadian neuroendocrine rhythms in the age-related development of obesity and insulin resistance was investigated in the male Sprague-Dawley rat. The phases and amplitudes of the plasma rhythms of several metabolic hormones (i.e., corticosterone, prolactin, insulin, and triiodothyronine) differed in lean, insulin-sensitive (3-week-old rats), insulin-resistant (8-week-old rats) and obese, insulin-resistant (44-week-old rats) animals. Simulation of the daily rhythms of endogenous corticosterone and prolactin by daily injections of the hormones at times corresponding to the peak levels found in 3-week-old rats reversed age-related increases in insulin resistance and body fat in older (5-6-month-old) rats. Ten such daily injections of corticosterone and prolactin in 12-14-week-old rats produced long-term reductions in body fat stores (30%), plasma insulin concentration (40%), and insulin resistance (60%) (determined by a glucose tolerance test) measured 11-14 weeks after the treatment. Alterations in circadian neuroendocrine rhythms may account for age-related changes in carbohydrate and lipid metabolism in the male Sprague-Dawley rat, and resetting of these rhythms by appropriately timed daily injections of corticosterone and prolactin may help maintain metabolism characteristic of younger animals.
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Affiliation(s)
- A H Cincotta
- Wellman Laboratories of Photomedicine, Massachusetts General Hospital, Boston 02114
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