Introduction; Principle Of The Test - DRG EIA-2395 Instrucciones De Uso

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INTRODUCTION

1.1 Intended Use
The DRG Leptin Sandwich ELISA is an enzyme immunoassay for the quantitative in vitro diagnostic measurement of
Leptin in serum or plasma.
1.2 Summary and Explanation
Leptin is produced primarily in the adipocytes of white adipose tissue and circulates in blood in free form and bound to
proteins (1). In mammals, leptin is pleiotropic, regulating a multitude of physiological processes. Leptin reduces appetite
and food intake, and inhibits hepatic glucose production, fatty acid synthesis and the expression of resistin. In contrast,
Leptin increases energy expenditure by inducing oxidation of fatty acids in liver and muscle. Moreover, Leptin stimulates
insulin secretion and glucose uptake as well as secretion of inflammatory cytokines (2,3). Leptin serves as a lipostatic
signal and conveys critical information regarding metabolic state to the brain by stimulating anorexic
proopiomelanocortin/cocaine and amphetamine-related transcript neurons and inhibiting orexigenic neuropeptide Y/
agouti-related protein neurons (4,5). The actions of Leptin are opposed by the hormone ghrelin. Both hormones act on
receptors in the arcuate nucleus of the hypothalamus to regulate appetite to achieve energy homeostasis (6).
Although leptin reduces appetite as a circulating signal, obese individuals generally exhibit a higher circulating
concentration of leptin than normal weight individuals due to their higher percentage body fat (7). These people show
resistance to leptin, similar to resistance of insulin in type 2 diabetes, with the elevated levels failing to control hunger and
modulate their weight. In obesity, a decreased sensitivity to leptin occurs, resulting in an inability to detect satiety despite
high energy stores (8). Although regulation of fat stores is deemed to be the primary function of leptin, it also plays a role
in other physiological processes, as evidenced by its multiple sites of synthesis other than fat cells, and the multiple cell
types beside hypothalamic cells that have leptin receptors.
Leptin-deficient pathologies are typically accompanied by hyperphagia and obesity (9,10). Extreme obesity can be
observed with mutations in the leptin receptor. The anorexigenic properties of leptin have been well characterized in the
context of leptin-deficient humans, resulting in the reduction of food intake and body mass (11,12).
In conclusion, Leptin can be measured for the differential diagnosis of obesity with leptin resistance.
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PRINCIPLE OF THE TEST

The DRG Leptin Sandwich ELISA is a solid phase enzyme-linked immunosorbent assay (ELISA) based on the sandwich
principle.
The microtiter wells are coated with a monoclonal antibody directed towards a unique antigenic site on a Leptin molecule.
An aliquot of patient sample containing endogenous Leptin is incubated in the coated well with a specific biotinylated
monoclonal anti-Leptin antibody. A sandwich complex is formed. After incubation the unbound material is washed off and
a Streptavidin Peroxidase Enzyme Complex is added for detection of the bound Leptin.
Having added the substrate solution, the intensity of colour developed is proportional to the concentration of Leptin in the
patient sample.
Version 10.0 2017/05 - vk
Leptin Sandwich ELISA EIA-2395
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