RESUMO
The vagus nerve (VN) and spleen represent a complex interface between neural and immunological functions, affecting both energy metabolism and white adipose tissue (WAT) content. Here, we evaluated whether vagal and splenic axis participates in WAT mass regulation in obese and non-obese male Wistar rats. High doses of monosodium glutamate (M; 4 g/Kg) were administered during the neonatal period to induce hypothalamic lesion and obesity (M-Obese rats). Non-obese or Control (CTL) rats received equimolar saline. At 60 days of life, M-Obese and CTL rats were randomly distributed into experimental subgroups according to the following surgical procedures: sham, subdiaphragmatic vagotomy (SV), splenectomy (SPL), and SV + SPL (n = 11 rats/group). At 150 days of life and after 12 h of fasting, rats were euthanized, blood was collected, and the plasma levels of glucose, triglycerides, cholesterol, insulin, and interleukin 10 (IL10) were analyzed. The visceral and subcutaneous WAT depots were excised, weighed, and histologically evaluated for number and size of adipocytes as well as IL10 protein expression. M-Obese rats showed higher adiposity, hyperinsulinemia, hypertriglyceridemia, and insulin resistance when compared with CTL groups (p < 0.05). In CTL and M-Obese rats, SV reduced body weight gain and triglycerides levels, diminishing adipocyte size without changes in IL10 expression in WAT (p< 0.05). The SV procedure resulted in high IL10 plasma levels in CTL rats, but not in the M-Obese group. The splenectomy prevented the SV anti-adiposity effects, as well as blocked the elevation of IL10 levels in plasma of CTL rats. In contrast, neither SV nor SPL surgeries modified the plasma levels of IL10 and IL10 protein expression in WAT from M-Obese rats. In conclusion, vagotomy promotes body weight and adiposity reduction, elevating IL10 plasma levels in non-obese animals, in a spleen-dependent manner. Under hypothalamic obesity conditions, VN ablation also reduces body weight gain and adiposity, improving insulin sensitivity without changes in IL10 protein expression in WAT or IL10 plasma levels, in a spleen-independent manner. Our findings indicate that the vagal-spleen axis influence the WAT mass in a health state, while this mechanism seems to be disturbed in hypothalamic obese animals.
RESUMO
AIMS: Obesity is associated with a spectrum of hepatic abnormalities that can be experimentally induced by injections of monosodium glutamate (MSG) in neonatal rodents. We investigated the protective actions of the repeated therapy with 4-phenylselenyl-7-chloroquinoline (4-PSQ), a quinoline derivative containing selenium, on damage to the liver triggered by early postnatal administration of MSG in male Wistar rats. MAIN METHODS: Neonatal rats received MSG (4 g/kg, subcutaneous route) or saline (1 ml/kg) from 5 to 14 postnatal day (PND) to induce obesity with consequent damages in the liver. 4-PSQ treatment (5 mg/kg) or canola oil (1 ml/kg) was administered from 60 to 76 PND by the intragastric route. On 76 PND, animals were anesthetized for blood and liver collection. Plasma markers of hepatic function, hepatic lipoperoxidation levels and histology analysis of liver tissue were assessed. KEY FINDINGS: Our data revealed that treatment with 4-PSQ reverted the increase in plasma transaminases activities observed in MSG rats. Treatment with 4-PSQ reduced plasma lactate levels in obese rats. In the liver, MSG elevated the content of lipoperoxidation which was reverted by 4-PSQ administrations. Lastly, 4-PSQ therapy attenuated the histological alterations induced by MSG. SIGNIFICANCE: Together, the results indicate a hepatoprotective action of repeated treatment with 4-PSQ in obese rats.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Aromatizantes/efeitos adversos , Fígado/efeitos dos fármacos , Compostos Organosselênicos/uso terapêutico , Substâncias Protetoras/uso terapêutico , Quinolinas/uso terapêutico , Glutamato de Sódio/efeitos adversos , Animais , Animais Recém-Nascidos , Doença Hepática Induzida por Substâncias e Drogas/patologia , Fígado/patologia , Masculino , Ratos WistarRESUMO
The pinealgland synthesizes melatonin exclusively at night, which gives melatonin the characteristic of a temporal synchronizer of the physiological systems. Melatonin is a regulator of insulin activities centrally and also peripherally and its synthesis is reduced in diabetes. Since monosodium glutamate (MSG) is often used to induce the type 2 diabetic and metabolic syndrome in animal models, the purpose of this work is to evaluate the potential effects of MSG given to neonates on the pineal melatonin synthesis in different agedmale and female rats. Wistar rats were subcutaneously injected with MSG (4mg/g/day) or saline solution (0.9%) from the second to eighth post-natal day. The circadian profiles both melatonin levels and AANAT activity were monitored at different ages. Body weight, naso-anal length, adipose tissues weight, GTT, ITT and serum insulin levels were also evaluated. Typical obesity with the neonatal MSG treatment was observed, indicated by a great increase in adipose depots without a concurrent increase in body weight. MSG treatment did not cause hyperglycemia or glucose intolerance, but induced insulin resistance. An increase of melatonin synthesis at ZT 15 with phase advance was observed in in some animals. The AANAT activity was positively parallel to the melatonin circadian profile. It seems that MSG causes hypothalamic obesity which may increase AANAT activity and melatonin production in pineal gland. These effects were not temporally correlated with insulin resistance and hyperinsulinemia indicating the hypothalamic lesions, particularly in arcuate nucleus induced by MSG in early age, as the principal cause of the increase in melatonin production.
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Modifications in life-style and/or pharmacotherapies contribute to weight loss and ameliorate the metabolic profile of diet-induced obese humans and rodents. Since these strategies fail to treat hypothalamic obesity, we have assessed the possible mechanisms by which duodenal-jejunal bypass (DJB) surgery regulates hepatic lipid metabolism and the morphophysiology of pancreatic islets, in hypothalamic obese (HyO) rats. During the first 5 days of life, male Wistar rats received subcutaneous injections of monosodium glutamate (4 g/kg body weight, HyO group), or saline (CTL). At 90 days of age, HyO rats were randomly subjected to DJB (HyO DJB group) or sham surgery (HyO Sham group). HyO Sham rats were morbidly obese, insulin resistant, hypertriglyceridemic and displayed higher serum concentrations of non-esterified fatty acids (NEFA) and hepatic triglyceride (TG). These effects were associated with higher expressions of the lipogenic genes and fatty acid synthase (FASN) protein content in the liver. Furthermore, hepatic genes involved in β-oxidation and TG export were down-regulated in HyO rats. In addition, these rats exhibited hyperinsulinemia, β-cell hypersecretion, a higher percentage of islets and β-cell area/pancreas section, and enhanced nuclear content of Ki67 protein in islet-cells. At 2 months after DJB surgery, serum concentrations of TG and NEFA, but not hepatic TG accumulation and gene and protein expressions, were normalized in HyO rats. Insulin release and Ki67 positive cells were also normalized in HyO DJB islets. In conclusion, DJB decreased islet-cell proliferation, normalized insulinemia, and ameliorated insulin sensitivity and plasma lipid profile, independently of changes in hepatic metabolism.
Assuntos
Animais , Masculino , Duodeno/cirurgia , Fígado Gorduroso/metabolismo , Derivação Gástrica/métodos , Doenças Hipotalâmicas/metabolismo , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/metabolismo , Jejuno/cirurgia , Obesidade/metabolismo , Animais Recém-Nascidos , Glicemia/metabolismo , Proliferação de Células , Colesterol/sangue , Ácido Graxo Sintase Tipo I/metabolismo , Ácidos Graxos/sangue , Fígado Gorduroso/fisiopatologia , Doenças Hipotalâmicas/fisiopatologia , Doenças Hipotalâmicas/cirurgia , Resistência à Insulina , Insulina/metabolismo , Ilhotas Pancreáticas/fisiopatologia , Lipogênese/genética , Fígado/metabolismo , Fígado/patologia , Obesidade/fisiopatologia , Obesidade/cirurgia , Pâncreas/metabolismo , Pâncreas/patologia , Distribuição Aleatória , Ratos Wistar , Reprodutibilidade dos Testes , Fatores de Tempo , Triglicerídeos/sangueRESUMO
Obesity and metabolic syndrome are the common causes of reproductive and fertility disorders in women. In particular, polycystic ovary syndrome, which is clinically characterized by hyperandrogenism, oligo/anovulation, and polycystic ovarian morphology, has been increasingly associated with metabolic disorders. However, given the broad interplay between metabolic and reproductive functions, this remains a field of intense research. In this study, we investigated the effect of monosodium l-glutamate (MSG)-induced obesity on reproductive biology of female rats. Newborn female rats were subcutaneously injected with MSG (4g/kg/day) or equiosmolar saline (CTR) each 2 days up to postnatal day (pnd) 10. On pnd 60, estrous cycle was evaluated using vaginal smears twice a day for 15 days, which showed MSG rats to be oligocyclic. Thereafter, animals were killed on estrous phase for blood and tissue collection. MSG rats had increased body mass, accumulation of retroperitoneal and visceral fat pads, and visceral adipocyte hypertrophy compared with CTR rats. MSG rats were also dyslipidemic and hyperinsulinemic but were normoglycemic and normoandrogenic. Ovarian morphology analysis showed that MSG rats had a two-fold decrease in oocyte count but a six-fold increase on ovarian follicular cysts, along with a higher number of total primordial and atretic follicles. Moreover, MSG rats had a four-fold increase in anti-Müllerian hormone immunohistochemical staining on antral follicles. Taken together, data presented here characterize MSG obesity as a unique model to study the metabolic pathways underlying reproductive disorders in the absence of overactivated hypothalamic-pituitary-gonadal axis.
Assuntos
Obesidade/induzido quimicamente , Obesidade/fisiopatologia , Glutamato de Sódio/toxicidade , Androgênios/metabolismo , Animais , Animais Recém-Nascidos , Hormônio Antimülleriano/metabolismo , Modelos Animais de Doenças , Feminino , Hiperinsulinismo/induzido quimicamente , Hiperinsulinismo/fisiopatologia , Redes e Vias Metabólicas/efeitos dos fármacos , Síndrome Metabólica/induzido quimicamente , Síndrome Metabólica/fisiopatologia , Obesidade/patologia , Ovário/efeitos dos fármacos , Ovário/metabolismo , Ovário/patologia , Síndrome do Ovário Policístico/induzido quimicamente , Síndrome do Ovário Policístico/fisiopatologia , Ratos , Ratos Wistar , Reprodução/efeitos dos fármacosRESUMO
O craniofaringioma é uma neoplasia de natureza benigna, pouco frequente, responsável por 1 por cento a 3 por cento de todos os tumores intracranianos, sendo a mais frequente neoplasia intracraniana não neuroepitelial na criança. Geralmente o tumor é restrito à região selar e ao III ventrículo, mas, em decorrência da infiltração e frequente aderência ao sistema nervoso central, apresenta comportamento clínico muitas vezes desfavorável, sendo classificado pela Organização Mundial de Saúde (OMS) como grau I, caracterizado como tumor de baixo ou incerto potencial de malignização. As sequelas endocrinológicas ganham destaque devido ao importante impacto na qualidade de vida dos pacientes, na maioria das vezes crianças. O hipopituitarismo e a obesidade hipotalâmica são complicações frequentes, sendo o tratamento desse tumor um grande desafio para endocrinologistas e neurocirurgiões. A combinação da cirurgia, radioterapia e aplicação de drogas e radioisótopos intratumorais tem como objetivo maximizar as chances de cura e tentar minimizar as sequelas pós-operatórias, mas, mesmo assim, a recidiva ainda é frequente. A escolha da modalidade de tratamento mais adequado para os craniofaringiomas é uma decisão difícil e que deve sempre ser individualizada para cada paciente. Com o objetivo de explorar as múltiplas opções terapêuticas para o craniofaringioma, foi realizada revisão na literatura com ênfase nas possibilidades terapêuticas e complicações inerentes ao tratamento dessa patologia.
Craniopharyngioma is an uncommon benign neoplasm, accounting for 1 percent-3 percent of all intracranial tumors, and the most common non-neuroepithelial intracranial neoplasm in childhood. Usually, the tumor is confined to the sellar region and the third ventricle, but due to frequent infiltration and adherence to the central nervous system, it often has an unfavorable clinical behavior. Therefore, it is classified by the World Health Organization (WHO) as a tumor of low or uncertain malignant potential. Endocrine after effects, mainly hypothalamic hypopituitarism, obesity and diabetes insipidus are highlighted due to their important impact on the quality of life of patients, mostly children. Optimal treatment of this tumor is a major challenge for neurosurgeons and endocrinologists. The combination of surgery, radiation, and application of radioisotopes and intratumoral drugs, aims at maximizing the chances of cure with minimal complications. Yet, recurrence is still frequent. Choosing the best treatment modality for craniopharyngiomas is a difficult decision, and it should always be specific for each case. In order to explore the multiple therapeutic options for craniopharyngiomas, we reviewed the literature with emphasis on the therapeutic possibilities and complications inherent to the treatment of this disease.