Hormones leptin

Other hormones Thyroxine has long been known to increase metabolic rate, although the mechanism for this effect is not totally clear (Silvestri et al. 2005). More recently the hormone leptin, which is secreted by adipose tissue, has also been found to increase the metabolic rate. This effect of leptin is considered to play a role in controlling the amount of adipose tissue in the body, although this is a controversial subject (Chapter 12). 

The hormone leptin is synthesized by adipocytes and is important in controlling body weight plasma leptin concentrations correlate with fat mass and insulin resistance. Leptin could be a link between obesity, insulin resistance syndrome, and treatment with some neuroleptic drugs. Plasma leptin concentrations are raised, regardless of weight, in patients taking clozapine (793). 

The underlying mechanism may involve the adipose tissue hormone leptin or immune modulators such as tumor necrosis factor alfa. 

T. Gura. Obesity sheds its secrets While the hormone leptin has dominated obesity research, new findings suggest it has help m regulating body weight. Results that may provide potennal avenues for obesity thei apies. Science, 27S, 751—753, 1997. 

Considerable interest continues to surroimd the adipocyte-derived hormone leptin (Greek, leptos, thin) which acts on the h)q)Othalamus to control... 

You have just cloned an EcoRl fragment that is 1650 base pairs Obp) and contains the gene for the hormone leptin. Your first job is to prepare a restriction enzyme map of the recombinant plasmid. You know that you have cloned into a plasmid vector that is 805 bp and that has only one EcoRl site (the one into which you cloned). There are no other restriction enzyme sites in the plasmid. The following table shows the restriction enzymes used and the DNA fragment sizes that result. Draw a map of the circular recombinant plasmid and a representation of die gel from which the fragment sizes were obtained. 

Gura, T. Obesity Sheds Its Secrets. Science 275, 751-753 (1997). [A Research News article on the role of the protein hormone leptin in obesity research and on the possibility of obesity therapies that might arise from this research.]... 

A possible reciprocal link may exist between endocannabinoid mechanisms and leptin, an appetite-suppressing peptide hormone. Leptin, released from adipocytes, is believed to signal the nutritional status to brain areas controlling appetite. It directly stimulates the action of anorexigenic... 

The client diagnosed with Type 2 diabetes mellitus and a body mass index (BMI) of 29 is prescribed the hormone leptin. Which intervention should the nurse implement ... 

The motion of the body-mass set point had led scientists to postulate that there must be a homeostatic signal from the fuel stores of the body to the brain. This has been referred to as a lipostat which can communicate the level of fuel stores to the brain to alter the appetite and metabolic rate control centers in the brain. In 1995, the hormone leptin was discovered. It is secreted by white adipose tissue at a rate that is proportional to the size of the fat reserves. The hypothalamus in the brain influences energy intake and expenditure, and it possesses receptors for leptin. Binding of leptin reduces food intake and increases whole body BMR. 

Carbohydration and polyethylene glycol linkers were combined with chemoselective conjugation to optimize the pharmacokinetics of the peptides investigated. Oxime formation was successfully adopted for chemoselective F-labeling of an aminooxy-modified affibody (Namavari et al. 2008) and a suitable derivative of the hormone leptin (Flavell et al. 2008). Recently, the [ F]FBA synthesis was automated and yielded [ F]FBA after 45 min in radiochemical yields of 54% and radiochemical purity of >99% after automated cartridge purification (Speranza et al. 2009). 

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