Separate measurement of plasma levels of acylated and desacyl ghrelin in healthy subjects using a new direct ELISA assay
Separate measurement of plasma levels of acylated and desacyl ghrelin in healthy subjects using a new direct ELISA assay
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DOI：
10.1210/jc.2004-1640
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发表时间：
2005-01-01
影响因子：
5.8
通讯作者：
Kangawa, K
中科院分区：
文献类型：
--
作者：
Akamizu, T;Shinomiya, T;Kangawa, K
两种形式的生长素释放肽（酰化和去酰基）在血浆中循环。尽管酰化被认为对于生长素释放肽生物活性至关重要，但最近的研究表明去酰基生长素释放肽也可能具有生物活性。现在，一种新的商业 ELISA 系统使我们能够分别测量这两种生长素释放肽形式的血浆水平。该测定系统使用少量血浆直接测量水平。为了评估该检测系统的实用性，我们测量了健康志愿者中两种形式的生长素释放肽的血浆水平。尽管酰化生长素释放肽水平与之前通过 RIA 测定的水平相当，但去酰基生长素释放肽水平低于之前通过 RIA 测定的总生长素释放肽水平预期的水平。酰化生长素释放肽与去酰基生长素释放肽的比率与之前测定的酰化生长素释放肽水平显着相关，但与去酰基生长素释放肽水平无关。体重指数调整后，女性受试者血浆中酰化生长素释放肽水平高于男性，但去酰基生长素释放肽水平则不然。一些代谢和激素参数与血浆酰化或去酰基生长素释放肽水平显着相关。这些发现表明，对两种生长素释放肽形式水平的单独测量可以提供有关其结构、性别差异和生理影响的有价值的信息。
Two forms of ghrelin, acylated and desacyl, circulate in plasma. Although acylation is thought to be essential for ghrelin biological activities, recent studies have suggested that desacyl ghrelin may also possess biological activity. A new commercial ELISA system has now enabled us to measure plasma levels of each of these two ghrelin forms separately. This assay system directly measures levels using small amounts of plasma. To evaluate the utility of this assay system, we measured the plasma levels of the two forms of ghrelin in healthy volunteers. Although acylated ghrelin levels were equivalent to those measured previously by RIA, desacyl ghrelin levels were lower than those expected from the total ghrelin levels previously determined by RIA. The ratios of acylated to desacyl ghrelin significantly correlated with previously determined acylated, but not desacyl, ghrelin levels. After BMI adjustment, the levels of acylated, but not desacyl, ghrelin plasma levels were higher in female subjects than those in males. Several metabolic and hormonal parameters significantly correlated with either plasma acylated or desacyl ghrelin levels. These findings indicate that separate measurements of the two ghrelin form levels may provide valuable information on their structure, gender differences, and physiological implications.