Despite many controversies, several studies have shown that there is a relationship between obesity and the increase in bone mass.8 and 9 Bone tissue is highly dynamic and is in a constant state of change, basically due to three processes: bone growth, modelling and remodelling. The latter is a continuous physiological process that allows the maintenance of bone strength and it is Sorafenib regulated by the interaction amongst bone cells and a variety of systemic hormones, cytokines, growth factors and inflammatory mediators. Obese individuals have higher bone mineral density (BMD) than non-obese individuals, and this may be a protective factor

against osteoporosis and fractures.10 Obesity may inhibit hepatic synthesis of the insulin-like growth factor binding proteins (IGFBP-3). IGFBP-3 is normally

associated with hyperinsulinemia and promotes greater activity of the insulin-like growth factor (IGF-I), which together with the direct activation of IGF-I receptors by insulin stimulate the proliferation of osteoblasts.11 and 12 Several studies have shown that leptin, a hormone secreted mainly by the adipose tissue, may have an important osteogenic effect on pubertal development and skeletal maturation.9 Other studies have indicated that if this hormone is administered directly on the cerebral ventricles of leptin-deficient mice, it may cause bone loss.8 Vorinostat chemical structure However, other authors concluded that leptin is a physiological anti-resorptive factor and it plays a role in the protective effects on bone mass.13 To study the origins of obesity and its pathological consequences, different experimental models of obese animals have been used, and amongst them, the one induced by monosodium glutamate (MSG) treatment. The administration of MSG in rats and mice during the first days after birth causes lesions in the arcuate nucleus and median eminence of the hypothalamus,14 and 15 altering the normal functioning of the hypothalamus–hypophysis axis. These animals are characterised by presenting deficiency

in the Farnesyltransferase release of the growth hormone16, 17 and 18; reduced basal metabolic rate, with increase in lipogenesis and diminished lipolysis19; hypo- or normophagia; obesity; hyperinsulinemia20 and 21; insulin resistance20 and increase in corticosterone and leptin concentrations.22 Several studies have been conducted to investigate the relationship between obesity and several chronic-degenerative diseases that accompany this epidemic. Nevertheless, despite evidence showing the interrelationships amongst obesity, bone remodelling and periodontal disease, the literature is very restricted, requiring much research in this scientific field. The aim of this study was to evaluate the relationship between the model of obesity induced by neonatal MSG treatment and induced periodontal disease.