Efeito da hiperalimentação na lactação sobre a regulação da adiposidade corporal e sinalização da grelina no tecido adiposo branco de camundongos jovens e adultos

• Autor(a) principal: Santos, Vivian de Melo Soares dos
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/12745
• topic: Ghrelin; Overfeeding; Adipose tissue; Grelina; Hiperalimentação; Tecido adiposo; Obesidade; Grelina; Tecido adiposo; Adiposidade; Lactação; CNPQ::CIENCIAS BIOLOGICAS::FISIOLOGIA

Obesity is a major public health problem that is growing worldwide, due to an imbalance between food intake and energy expenditure is a major risk factor for the development of most prevalent chronic diseases as dyslipidemias, heart disease and type 2 diabetes, resulting in reduced quality and life expectancy. Ghrelin is a hormone synthesized by the stomach that acts in different tissues via a specific receptor (GHS-R1a), including hypothalamus and adipose tissue. For instance, recent reports have shown that ghrelin has a direct action on hypothalamic regulation of food intake mainly inducing an orexigenic effect. On the other hand, ghrelin also modulates energy stores and expenditure in the adipocytes. This dual action has suggested that this hormone may act as a link between the central nervous system and peripheral mechanisms. Furthermore, concerning nutritional disorders, it has been suggested that obesity may be considered an impairment of the above cited link. Therefore, considering that neonatal overfeeding induces obesity in adulthood by unknown mechanisms, in this study we examined the effects of early life overnutrition on the development of obesity and in particular on adipose tissue ghrelin signaling in young mice. Our data demonstrated that overnutrition during early life induces a significant increase in body weight of young mice, starting at 10 days, and this increase in weight persisted until adulthood (180 days of age). In these animals, blood glucose and visceral fat weight were found higher at 21 and 180 days when compared to the control group. Acylated ghrelin circulating levels were found lower in the young obese pups and adult obese mice. In addition, in white adipose tissue ghrelin receptor (GHS-R1a) expression increased and was associated to positive modulation of content and phosphorylation of proteins involved in cell energy store and use as AKT, PI3K, AMPK, GLUT-4, and CPT1. However adulthood overfeeding animals showed no significant difference in the content of GHS-R1a and protein AKT, PI3K, AMPK, GLUT-4, and CPT1. PPARγ content decreased in obese group at 21 and 180 days. Basically, we showed that adipose tissue metabolism is altered in early life acquired obesity and probably due to such modification a new pattern of ghrelin signaling pathway takes place.