Obese gene Obesity

Nadler ST et al. The expression of adipo-genic genes is decreased in obesity and diabetes mellitus. Proc Natl Acad Sci USA 2000 97 11371-11376. 

Hopkins PN, Lifton RP, Hollenberg NK, Jeunematre X, Hallouin MC, Skuppin J, Williams CS, Dluhy RG, La-louel JM, Williams RR, Williams GH. Blunted renal vascular response to angiotensin II is associated with a common variant of the angiotensinogen gene and obesity. J Hypertens 1996 14 199-207. 

NK. Blunted renal vascular response to angiotensin II is associated with a common variant of the angiotensinogen gene and obesity. J Hypertens 1996 14 199-207. 

Gagnon J, Mauriege P, Roy S, Sjo-strom D, Chagnon YC, Dionne FT, Op-pert J-M, Perusse L, Sjostrom L, Bouchard C. The Trp64Arg mutation of the j 3-adrenergic receptor gene has no effect on obesity phenotypes in the Quebec family study and Swedish obese subjects cohorts. J Clin Invest 1996 98 2086-2089. 

Sipilainen R, Uusitupa M, Heikkinen S, Rissanen A, Laakso M. Polymorphism of the / 3-adrenergic receptor gene affects basal metabolic rate in obese Finns. Diabetes 1997 46 77-80. 

Mauriege P, Bouchard C. The Trp64Arg mutation in the / -adrenoreceptor gene of doubtful significance for obesity and insulin resistance. Lancet 1996 348 698-699. 

Comuzzie AG, Allison DB. The search for human obesity genes. Science 1998 280(5368) 1374—1377-... 

Not all people who have obesity genes will be overweight. Conversely, some people who are overweight will not have these genes. This is because environmental factors also play a major role in causing overweight and obesity. 

Figure 2.3 Researchers are currently studying laboratory rodents, like the mice in the upper photograph, to try to identify specific genes that may lead to obesity. The two mice shown are the same, except that the mouse on the left has had one gene removed. As you can see, the mouse on the left is thin, while the mouse on the right is obese. This leads researchers to believe that the gene removed may help cause obesity. By better understanding the causes of obesity, researchers will be better able to develop treatments for this condition in humans.

Diabetes insipidus occurs with a loss of vasopressin production in the Brattleboro rat model 330 Mutations and knockouts of peptide-processing enzyme genes cause a myriad of physiological problems 330 Neuropeptides play key roles in appetite regulation and obesity 330 Enkephalin knockout mice reach adulthood and are healthy 331 Neuropeptides are crucial to pain perception 331... 

Neuropeptides play key roles in appetite regulation and obesity. Many genes for neuropeptides and neuropeptide receptors have been implicated in obesity and cachexia, anorexia and bulimia [34]. For example,NPY administration into the CNS causes overeating and obesity. A second peptide involved in obesity is leptin, a product of adipocytes and the stomach. The leptin gene is defective in the ob/ob mouse but in normal mice leptin binds to its receptor in the hypothalamus, causing a decrease in the synthesis and release of hypothalamic NPY. 

Genetic factors appear to be the primary determinants of obesity in some individuals, whereas environmental factors are more important in others. The specific gene that codes for obesity is unknown there is probably more than one gene. 

Madej, T., Boguski, M. S., and Bryant, S. H. (1995). Threading analysis suggests that the obese gene product may be a helical cytokine. FEES Lett. 373, 13-18. 

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