超敏瘦素检测试剂盒（酶联免疫法）产品说明:

【产品名称】

通用名称：超敏瘦素检测试剂盒（酶联免疫法）

英文名称：Leptin Sensitiv ELISA

【预期用途】

用于定量检测人血清或血浆中瘦素。仅供科研使用。不用于临床诊断。

【包装规格】

96T/盒

【背景知识】

1994 年，蛋白激素瘦素被鉴定为 ob 基因 (1,2) 的产物，其分子量为 16 kD，被认为在体重调节中起关键作用。其氨基酸序列与其他蛋白质没有主要同源性 (1)。瘦素几乎完全由分化的脂肪细胞产生 (3-5)。它作用于中枢神经系统，尤其是下丘脑，抑制食物摄入并增加能量消耗 (2,6-9)。存在不同剪接形式的瘦素受体，长度不同，它们属于细胞因子 1 类受体家族 (10-12)，在体内无处不在 (10,11,

13,14)。这表明瘦素的综合功能尚未完全了解。

许多瘦素结合蛋白中的一种代表瘦素受体的循环形式 (15)。

除了对新陈代谢的影响外，瘦素还对许多内分泌轴有很强的影响。在雄性小鼠中，它分别减弱了饥饿引起的 LH、睾酮和甲状腺素的显着下降以及 ACTH 和皮质酮的增加。在雌性小鼠中，瘦素可防止饥饿引起的排卵延迟 (16)。由于 ob 基因突变而缺乏瘦素的 Oblob 小鼠是不育的。这种缺陷可以通过瘦素应用来纠正，但不能通过禁食导致的体重减轻来纠正 (17)。这表明瘦素在生殖中起着重要作用。

瘦素的作用至少可以部分解释为瘦素对弓形核神经元形成和分泌神经肽 Y (NPY) 的抑制作用 (6,18,19)。NPY 是一种有效的食欲刺激剂 (20 ,21) 并且已知参与调节各种垂体激素。例如，这些包括通过刺激生长抑素来抑制生长激素 (22,23)、抑制促性腺激素 (23) 和刺激垂体-肾上腺轴 (21)。

决定循环瘦素浓度的最重要变量是体脂肪量 (24-26)。在定期进食的情况下，瘦素反映了脂肪组织的百分比 (27)。瘦素浓度随脂肪量呈指数增加。瘦素的这种组成合成受多种非激素和激素因素的调节。啮齿动物和人类的刺激物是暴饮暴食 (28,29)、胰岛素 (3,5,30-33) 和糖皮质激素 (5,34-36)。

一般来说，瘦素是各种代谢和内分泌反馈回路的重要组成部分。

对于临床使用，重要的是要注意瘦素水平显示出适度的昼夜节律变化，在凌晨 2 点左右达到峰值 (37)。此时的瘦素水平大约比早上或下午早些时候测量的水平高 30-100%。随着食物摄入量，在抽取血样时必须考虑这些波动。在标准化条件下，例如正常的饮食节奏和早上或下午早些时候的采血，瘦素测量足以提供信息性陈述。

需要参考范围才能对测量的瘦素值进行有意义的解释。由于体重对数值的影响最大，所以参考范围应与体脂量（Body Mass Index，BML，或体脂百分比，由 Bioelectrical Impedance Estimation，BIA 确定）相关。瘦素水平存在年龄依赖性 (38)。此外，对于相同的脂肪量，女性的瘦素水平高于男性 (39,40)。因此，参考范围还应考虑性别和青春期发育。

肥胖人群中常见的高水平瘦素表明瘦素不敏感（20,26,37,38,41,42）。然而，在少数患者中发现瘦素水平相对于体脂肪量不成比例地低。需要进一步的研究来证明这些患者代表了一种新的病理生理状况：瘦素缺乏症。由于瘦素对生殖功能非常重要，因此可能会发现将不孕症与瘦素产生不足联系起来的新病理生理机制。

如果饮食节奏正常，在早上或下午早些时候采集一次血样就足够了。

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