Parkes J G, Chan P, Goldberg D M
Biochem Cell Biol. 1986 Nov;64(11):1147-52. doi: 10.1139/o86-151.
Hepatic triglyceride lipase (HTGL) was measured in primary rat hepatocytes maintained for 3 days under three different culture conditions: basal medium, basal medium plus insulin, and basal medium plus insulin and phenobarbital. The activity of HTGL secreted by these cells was measured by treating intact cells with heparin; intracellular enzyme was subsequently measured in cell homogenates. Insulin stimulated intracellular triglyceride lipase activity by 48% and extracellular lipase by 30%. Phenobarbital, an enzyme-inducing drug, caused a further 15% increase in extracellular hepatic triglyceride lipase; whereas, the intracellular activity was reduced. The presence of insulin greatly stimulated the rate of enzyme secretion, and this rate was not notably affected by the presence of phenobarbital. After 3 days in culture, the short term (2-8 h) synthesis and secretion of enzyme from cultures treated with insulin or insulin plus phenobarbital were equally inhibited by cycloheximide. Monensin also inhibited enzyme secretion in both cultures and caused a similar increase in intracellular lipase activities. Insulin did not significantly affect the proportion of intracellular enzyme (17.7% basal vs. 15.8% insulin). On the other hand phenobarbital produced a 20-30% reduction in the proportion of intracellular enzyme (12.5 vs. 17.7% basal or 15.8% insulin). These findings suggest a drug-induced redistribution of triglyceride lipase.
在三种不同培养条件下将原代大鼠肝细胞培养3天，测定肝甘油三酯脂肪酶（HTGL）：基础培养基、基础培养基加胰岛素、基础培养基加胰岛素和苯巴比妥。通过用肝素处理完整细胞来测量这些细胞分泌的HTGL活性；随后在细胞匀浆中测量细胞内酶活性。胰岛素使细胞内甘油三酯脂肪酶活性增加48%，使细胞外脂肪酶活性增加30%。苯巴比妥是一种酶诱导药物，可使细胞外肝甘油三酯脂肪酶进一步增加15%；而细胞内活性降低。胰岛素的存在极大地刺激了酶的分泌速率，而苯巴比妥的存在对该速率没有显著影响。培养3天后，用胰岛素或胰岛素加苯巴比妥处理的培养物中酶的短期（2 - 8小时）合成和分泌均受到环己酰亚胺的抑制。莫能菌素也抑制两种培养物中的酶分泌，并使细胞内脂肪酶活性产生类似增加。胰岛素对细胞内酶的比例没有显著影响（基础状态下为17.7%，胰岛素处理后为15.8%）。另一方面，苯巴比妥使细胞内酶的比例降低20 - 30%（基础状态下为12.5%，与17.7%基础状态或15.8%胰岛素处理相比）。这些发现提示药物诱导了甘油三酯脂肪酶的重新分布。
