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Regulation of food intake. Food intake. Regulation Endocrine Adipose tissue Pancreas Liver Muscle CNS. Critical area of study Type II diabetes Obesity Hormones involved in appetite regulation Interaction with insulin Glucose uptake Triglyceride metabolism. Endocrine factors.
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Food intake • Regulation • Endocrine • Adipose tissue • Pancreas • Liver • Muscle • CNS
Critical area of study • Type II diabetes • Obesity • Hormones involved in appetite regulation • Interaction with insulin • Glucose uptake • Triglyceride metabolism
Endocrine factors • Adipose tissue • Leptin • Adiponectin • Resistin • GI tract • Ghrelin
Leptin • Product of ob gene • 16 kDa • No major similarity with other hormones
Produced by differentiated adipocytes • Acts on the CNS • Hypothalamus • Anorectic hormone • Appetite suppression • Acts on endocrine organs • Pancreas • Liver
Interaction with reproductive axis • Starvation • Reduced leptin level • Reduced reproductive efficiency • Suppression of HP-gonadal axis • Interaction between food intake and reproduction (detection of energy adequacy)
Mechanism of action • Leptin receptor • Type I cytokine receptor • Several isoforms • Found throughout body • Leptin binding proteins
Mechanism of action • CNS • Suppression of neuropeptide Y expression in brain • Suppression of appetite
Circulating leptin concentrations • Determined by body fat mass • Secretion regulated by nonhormonal and hormonal factors • Stimulatory • Insulin • Glucocorticoids • Overeating • Inhibitory • Fasting • cAMP • Beta receptor agonists
Clinical significance • Hyperleptinemia • Human obesity • Associated with body mass index • Basal leptin concentrations • Positively correlated with insulin if a person is insulin-sensitive • Not influenced by age, basal glucose concentrations
Eating disorder • Anorexia nervosa and bulimia nervosa • Leptin concentrations relfect BMI • Body fat content • Weight maintenance • Leptin concentrations reflect body fat mass • Weight loss/gain • Sensor of energy imbalance