[Leptin and its biological and clinical significance. Is leptin and insulin resistance in the X-5H hormonal metabolic syndrome a parallel or causally-linked phenomenon?].
Leptin 167 an amino acid product of the recently discovered obesity gene "ob-gene", is a tissue hormone of adipose tissue. It is a hormonal satiety signal or a signal for terminating food intake. Its level rise after a meal or after administration. Rats with a mutation of the ob-gene have zero or very low leptin levels, are hyperphagic, obese and sterile, develop diabetes as a result of overeating. Administration of recombinant leptin arrests hyperphagia, the body weight declines and sexual function improve partly, in particular in males. It seems that leptin controls not only the function of the hypothalamic satiety centre but also the output of GnRh and other liberins as well as thermoregulation, muscular and sexual activity and thus energy expenditure. In the majority of obese rats and human the leptin levels are significantly higher compared with asthenic individuals, proportionate to the percentage of body fat and BMI. Obesity promotes also insulin resistance and penetration of the H-phenomenon into the phenotype. In the insulin resistance syndrome (5H-X) it may thus be assumed that there is a parallel leptin and insulin resistance, probably of the postreceptor type, and even a causal association, as the "db" gene is identical with the gene for leptin receptors.
Hrnciar
J
J
Interná klinika nemocnice F.D. Roosevelta, Banská Bytstrica.
D000818:Animals; D006801:Humans; D007333:Insulin Resistance; D020738:Leptin; D009765:Obesity / Q000235:genetics / Q000503:physiopathology*; D011506:Proteins / Q000235:genetics / Q000502:physiology*
D020738:Leptin; D011506:Proteins
Leptín a jeho biologicko-klinický význam. Sú leptínová a inzulínová rezistencia u hormonálne-metabolického syndrómu X-5H pararelné alebo kauzálne zviazané fenomény?