The specific activities of human digestive lipases measured from the in vivo and in vitro lipolysis of test meals
The specific activities of human digestive lipases measured from the in vivo and in vitro lipolysis of test meals
复制标题
DOI：
10.1053/gast.2000.18140
复制
发表时间：
2000-10-01
期刊：
影响因子：
29.4
通讯作者：
Verger, R
中科院分区：
文献类型：
--
作者：
Carrière, F;Renou, C;Verger, R
背景与目的：迄今为止，消化脂肪酶在体内的脂肪分解潜力一直是根据其在非生理条件下的体外活性来推断的，在本研究中，在测试膳食脂肪分解过程中，通过膳食甘油三酯（TG）测量人胃脂肪酶（HGL）和胰脂肪酶（HPL）的比活性，方法：健康人类志愿者摄入液体或固体膳食，HGL和HPL的比活性根据脂肪酶和游离脂肪酸（FFA）分别在幽门后和十二指肠水平输出。基于体内数据，还在体外通过将膳食与胃液混合，随后与胰液和胆汁或与纯化的HGL和HPL混合来进行脂肪分解，通过薄层色谱法测量FFA，并且HGL和HPL的比活性表示为每分钟每毫克脂肪酶的微摩尔FFA，结果：在体外，液体膳食TG的比活性分别为32（胃液）和34（纯脂肪酶）μ HGL 为 mol.min(-1).mg(-1)，HPL 为 47（胰液）和 43（纯脂肪酶）mu mol.min(-1).mg(-1)。固体粉TG的比活性分别为33（胃液）和32（纯脂肪酶）μ mol.min(-1).mg(-1)（HGL）和12（胰液）和15（纯脂肪酶）μ mol.min(-1).mg(-1)（HPL），获得的体内值在相同范围内，分泌性脂肪酶输出为21.6+/-液体测试餐中含有 14.5 mg HGL 和 253.5 +/- 95.5 mg HPL，固体测试餐中含有 15.2 +/- 5.1 mg HGL 和 202.9 +/- 96.1 mg HPL，结论：HGL 和 HPL 对膳食 TG 的比活性远低于在优化测定条件 (1300-8000) 下体外测量的活性。然而，考虑到膳食中 HGL 和 HPL 的分泌量，这些低比活性足以使膳食 TG 完全脂解。
Background & Aims: The lipolytic potential of digestive lipases in vivo has always been deduced so far from their in vitro activities under nonphysiologic conditions, In the present study, the specific activities of human gastric lipase (HGL) and pancreatic lipase (HPL) were measured on dietary triglycerides (TGs) during test meal lipolysis, Methods: Healthy human volunteers ingested a liquid or solid meal, The specific activities of HGL and HPL were estimated from the lipase and free fatty acid (FFA) outputs at the postpyloric and duodenal levels, respectively. Based on the in vivo data, lipolysis was also performed in vitro by mixing the meal either with gastric juice and subsequently with pancreatic juice and bile or with purified HGL and HPL, FFAs were measured by thin-layer chromatography, and the specific activities of HGL and HPL were expressed as micromoles of FFA per minute per milligram of lipase, Results: In vitro, the specific activities on the liquid meal TGs were 32 (gastric juice) and 34 (pure lipase) mu mol.min(-1).mg(-1) with HGL and 47 (pancreatic juice) and 43 (pure lipase) mu mol.min(-1).mg(-1) with HPL. The specific activities on the solid meal TGs were 33 (gastric juice) and 32 (pure lipase) mu mol.min(-1).mg(-1) with HGL and 12 (pancreatic juice) and 15 (pure lipase) mu mol.min(-1).mg(-1) with HPL, The in vivo values obtained were in the same range, The secretory lipase outputs were 21.6 +/- 14.5 mg HGL and 253.5 +/- 95.5 mg HPL with the liquid test meal and 15.2 +/- 5.1 mg HGL and 202.9 +/- 96.1 mg HPL with the solid test meal, Conclusions: The specific activities of HGL and HPL on meal TGs were much lower than those measured in vitro under optimized assay conditions (1300-8000). However, these low specific activities are enough for the meal TGs to be completely lipolysed, given the amounts of HGL and HPL secreted during a meal.