LEPTIN AS A METABOLIC REGULATOR DURING FETAL AND NEONATAL LIFE AND INCHILDHOOD AND ADOLESCENCE

Body weight is regulated by a feedback loop in which peripheral signal s report nutritional information to an integratory center in the brain , The cloning of the ob gene is consistent with this concept and sugge sts that body fat content in adult rodents is regulated by a negative feedback loop centered in the hypothalamus /1-8/, In a recent report, two severely obese: children with congenital leptin deficiency due to a homozygous frame-shift mutation involving the deletion of a single g uanine nucleotide in codon 133 of the ob gene have been described, Thi s discovery provides the first genetic evidence that leptin is an impo rtant regulator of energy balance in humans, However, it has become in creasingly clear that apart from leptin's function in the central nerv ous system and in regulation of energy balance, leptin also acts in th e periphery and might be important as a hormone modulating processes i n regard to reproduction, glucose metabolism and insulin resistance, a s well as growth and development of many tissues and organs either dir ectly or indirectly. This report reviews some of the topics of leptin research that are of particular importance and relevance for pediatric and adolescent medicine and for pediatric endocrinology in particular .