Anorexigenic effect of cholecystokinin is lost but that of CART (Cocaine and Amphetamine Regulated Transcript) peptide is preserved in monosodium glutamate obese mice

Abstract

Monosodium glutamate (MSG) treatment of neonatal mice results in a selective damage to the arcuate nucleus (ARC) and development of obesity with increased adiposity at sustained body weight in the adulthood. Feeding pattern of the MSG obese mice is unusual. Our previous results showed that after 24-h fasting, MSG mice consumed negligible amount of food in several hours and therefore, it was impossible to register the effect of peptides attenuating food intake such as cholecystokinin (CCK) or cocaine- and amphetamine-regulated transcript (CART) peptide. To overcome this problem, two findings were used: firstly, orexigenic effect of neuropeptide Y (NPY) was attenuated both by CCK or CART peptide in lean fed mice and secondly, orexigenic effect of NPY was preserved in fed rats with MSG obesity. In this study, short-term food intake in fed lean and MSG obese C57BL/6 male mice was measured after simultaneous central administration of orexigenic NPY with either CART peptide or peripherally administered CCK. Anorexigenic action of exogenous CART peptide was preserved in MSG obese mice. On the other hand, satiety effect of exogenous CCK was completely lost in MSG obese mice. In conclusion, effective leptin signaling in ARC is necessary for satiety effect of CCK.

Drogas Imunossupressoras Afetam Os Núcleos Hipotalâmicos Envolvidos Na Ingestão Alimentar ? Estudo Experimental

“…Além disso, com base em modelos experimentais, por meio da injeção de glutamato monossódico em altas concentrações em camundongos, foi relatado o rápido ganho de peso dos animais devido à alta toxicidade causada nas células dos núcleos hipotalâmicos envolvidos com a ingestão de alimentos 24,28 .…”

“…Furthermore, based on experimental models, through the injection of high concentrations of monosodium glutamate in mice, the rapid gain of animal weight was reported due to the high toxicity caused in the cells of the hypothalamic nuclei involved with food intake 24 , 28 .…”

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“…[14] The results show that the CCK hormone exerts its effects on appetite by blocking the orexigenic neurons particularly Y neuropeptide neurons (NPY). [15,16] Our previous study also showed that devil's claw extract reduces body weight by increasing the secretion of leptin hormone and reduced Y neuropeptide hormone. [11] Furthermore, the ceased inhibitory effect of leptin hormone on food intake by CCK receptor antagonists has proved synergistic effects of these two hormones in the body weight and food intake.…”

Atenuación de parámetros metabólicos, inflamatorios y de estrés oxidante a lo largo de la vida de ratones obesos GMS

“…La obesidad se define como el exceso de grasa corporal o de tejido adiposo, siendo el resultado de una excesiva ingesta de nutrientes y/o de gasto energético disminuido, mantenido de forma crónica (Aitlhadj et al, 2011). Así mismo la obesidad se caracteriza por el resultado combinado de disfunción del centro de saciedad a nivel cerebral, desbalance de ingesta y empleo de energía, y variaciones genéticas (Cheung et al, 2012;Zelezná et al, 2009), manifestándose en un incremento o acumulación anormal o excesiva de energía en forma de grasa en el tejido adiposo (TA) (Blancas et al, 2010). Algunos autores resaltan la importancia del entorno en su desarrollo, debido a que en este trastorno nutricional influyen arraigadas y profundas normas sociales, difícilmente modificables (Oda, 2008).…”

“…La obesidad es un factor de riesgo para un amplio rango de enfermedades que incluyen resistencia a insulina, diabetes tipo 2, dislipidemia y enfermedad cardiovascular, entre otras (Andreazzi et al, 2009;Zelezná et al, 2009;Nickelson et al, 2012). La obesidad tambien ha sido considerada como un proceso de inflamación crónica sistémica de bajo grado, con una importante relación en la inducción de la resistencia a insulina (RI) (Furuya et al, 2010).…”