Vitamin D supplementation combined with aerobic physical exercise restores the cell density in hypothalamic nuclei of rats exposed to monosodium glutamate.

BACKGROUND & AIMS: In view of the increase in the prevalence of obesity and metabolic syndrome in childhood and adolescence, this study proposed the early and combined use of treatments to restore brain areas related to satiety. The vitamin D supplementation, aerobic exercise and the combination of these interventions on the structure of arcuate (ARC) and ventromedial (VMH) nuclei of hypothalamus were investigated in monosodium glutamate (MSG)-treated rats. METHODS: Wistar rats were separated into five groups: Control group (CT); Obese group injected with MSG (OB); Obese group supplemented with vitamin D (OBvd); Obese group submitted to forced swimming training (OBexe) and Obese group treated with vitamin D supplementation and forced swimming training (OBvd + exe). RESULTS: In the OB group, the visceral fat weight was significantly higher, there was a reduction in the number of glial cells in the ARC nucleus and also in the number of neurons in the ARC and VMH nuclei. Aerobic exercise was able to reduce the visceral fat weight in the OBexe group. The combination of treatments used in the OBvd + exe group reversed the loss of neurons and glial cells produced by MSG in the ARC nucleus. All treated groups exhibited a higher number of neurons in VMH nucleus, but an increase in the glial cells were observed only in the OBexe and OBvd + exe groups. CONCLUSIONS: The effectiveness of obesity treatment can be favored through the early and combined use of vitamin D supplementation and aerobic exercise, since these therapies are able to restore brain nuclei involved in the control of food intake.

DUODENAL-JEJUNAL BYPASS REDUCES LIPID ACCUMULATION IN THE BROWN ADIPOSE TISSUE OF HYPOTHALAMIC OBESE RATS.

BACKGROUND: Effects of duodenal-jejunal bypass surgery (DJB) on the proliferation of nuclei and the area of adipocytes in the brown adipose tissue of obese rats. Thermogenic activity in the brown adipose tissue (BAT) of obese individuals is reduced, and this condition may be modified by bariatric surgery (BS). AIM: To characterize fat deposition in BAT from hypothalamic obese (HyO) rats submitted to duodenal-jejunal-bypass (DJB) surgery. METHODS: For induction of hypothalamic obesity, newborn male Wistar rats were treated with subcutaneous injections of monosodium glutamate (MSG). The control (CTL) group received saline solution. At 90 days, the HyO rats were submitted to DJB or sham operation, generating the HyO-DJB and HyO-SHAM groups. At 270 days, the rats were euthanized, and the BAT was weighed and submitted to histological analysis. RESULTS: Compared to BAT from CTL animals, the BAT from HyO-SHAM rats displayed increased weight, hypertrophy with greater lipid accumulation and a reduction in nucleus number. DJB effectively increased nucleus number and normalized lipid deposition in the BAT of HyO-SHAM rats, similar to that observed in CTL animals. CONCLUSION: DJB surgery avoided excessive lipid deposition in the BAT of hypothalamic obese rats, suggesting that this procedure could reactivate thermogenesis in BAT, and contribute to increase energy expenditure.

Duodenal-jejunal bypass reduces lipid accumulation in the brown adipose tissue of hypothalamic obese rats / Derivação duodeno-jejunal reduz o acúmulo de lipídios no tecido adiposo marrom de ratos com obesidade hipotalâmica

ABSTRACT Background: Thermogenic activity in the brown adipose tissue (BAT) of obese individuals is reduced, and this condition may be modified by bariatric surgery (BS). Aim: To characterize fat deposition in BAT from hypothalamic obese (HyO) rats submitted to duodenal-jejunal-bypass (DJB) surgery. Methods: For induction of hypothalamic obesity, newborn male Wistar rats were treated with subcutaneous injections of monosodium glutamate (MSG). The control (CTL) group received saline solution. At 90 days, the HyO rats were submitted to DJB or sham operation, generating the HyO-DJB and HyO-SHAM groups. At 270 days, the rats were euthanized, and the BAT was weighed and submitted to histological analysis. Results: Compared to BAT from CTL animals, the BAT from HyO-SHAM rats displayed increased weight, hypertrophy with greater lipid accumulation and a reduction in nucleus number. DJB effectively increased nucleus number and normalized lipid deposition in the BAT of HyO-SHAM rats, similar to that observed in CTL animals. Conclusion: DJB surgery avoided excessive lipid deposition in the BAT of hypothalamic obese rats, suggesting that this procedure could reactivate thermogenesis in BAT, and contribute to increase energy expenditure.

RESUMO Racional: A atividade termogênica no tecido adiposo marrom (TAM) de indivíduos obesos encontra-se reduzida, condição que pode ser modificada pela cirurgia bariátrica(CB). Objetivo: Verificar o efeito da derivação duodeno-jejunal (DDJ) sobre a morfologia do TAM de ratos com obesidade hipotalâmica. Métodos: Para indução da obesidade hipotalâmica (OHi), ratos Wistar neonatos receberam injeções subcutâneas de glutamato monossódico (MSG). O grupo controle (CTL) recebeu solução salina. Aos 90 dias, os ratos OHi foram submetidos à DDJ (grupo OHi-DDJ) ou a falsa operação (grupo OHi-FO). Aos 270 dias, eles foram eutanasiados e o TAM foi pesado e submetido à análise histológica. Resultados: Em comparação com os animais CTL, o TAM dos ratos OHi-FO apresentou aumento do peso, hipertrofia dos adipócitos com acúmulo de lipídios e redução do número de núcleos. A DDJ reduziu a deposição de gordura e o número de núcleos no TAM de ratos OHi-DDJ em comparação com os OHi-FO, com valores similares aqueles dos animais CTL. Conclusões: A DDJ foi capaz de evitar a deposição excessiva de lipídios no TAM de ratos com obesidade hipotalâmica, sugerindo que a cirurgia bariátrica poderia reativar a termogênese neste tecido adiposo, contribuindo para aumentar o gasto energético.