Cholecystokinin (CCK) is a peptide hormone secreted from enteroendocrine cells and regulates the exocrine pancreas, gastric motility, and appetite. Dietary triacylglycerols are hydrolyzed to fatty acids (FA) and 2-monoacylglycerols (2-MAG) in the small intestine. Although it is well known that FA stimulate CCK secretion, whether 2-MAG have the CCK-releasing activity remains unclear. We examined the CCK-releasing activity of four commercially available 2-MAG in a murine CCK-producing cell line, STC-1, and the molecular mechanism underlying 2-MAG-induced CCK secretion. CCK released from the cells was measured using ELISA. Among four 2-MAG (2-palmitoyl, 2-oleoyl, 2-linoleoyl, and 2-arachidonoyl monoacylglycerols) examined, 2-arachidonoyl glycerol (2-AG) potently stimulated CCK secretion in a dose-dependent manner. Structurally related compounds, such as 2-arachidonoyl glycerol ether and 1-arachidonoyl glycerol, did not stimulate CCK secretion. Both arachidonic acid and 2-AG stimulated CCK secretion at 100 μM, but only 2-AG did at 50 μM. 2-AG-induced CCK secretion but not arachidonic acid-induced CCK secretion was attenuated by treatment with a cannabinoid receptor 1 (CB1) antagonist. These results indicate that a specific 2-MAG, 2-AG, directly stimulates CCK secretion via CB1.

中文翻译：

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2-花生四烯酸甘油通过大麻素受体 CB1 有效诱导小鼠肠内分泌 STC-1 细胞中胆囊收缩素的分泌

胆囊收缩素 (CCK) 是一种由肠内分泌细胞分泌的肽激素，可调节胰腺外分泌、胃动力和食欲。膳食中的甘油三酯在小肠中水解为脂肪酸 (FA) 和 2-单酰基甘油 (2-MAG)。虽然众所周知 FA 刺激 CCK 分泌，但 2-MAG 是否具有 CCK 释放活性仍不清楚。我们检测了四种市售 2-MAG 在小鼠 CCK 产生细胞系 STC-1 中的 CCK 释放活性，以及​​ 2-MAG 诱导的 CCK 分泌的分子机制。使用ELISA测量从细胞释放的CCK。在检查的四种 2-MAG（2-棕榈酰、2-油酰、2-亚油酰和 2-花生四烯酸单酰基甘油）中，2-花生四烯酸甘油 (2-AG) 以剂量依赖性方式有效刺激 CCK 分泌。结构相关的化合物，如2-花生四烯酸甘油醚和1-花生四烯酸甘油，不刺激CCK分泌。花生四烯酸和 2-AG 在 100 μM 时都刺激 CCK 分泌，但在 50 μM 时只有 2-AG 有作用。用大麻素受体 1 (CB1) 拮抗剂治疗可减弱 2-AG 诱导的 CCK 分泌，而非花生四烯酸诱导的 CCK 分泌。这些结果表明特定的 2-MAG，2-AG，通过 CB1 直接刺激 CCK 分泌。