糖尿病对大鼠心脏分离心肌细胞中酸性和中性三酰甘油脂肪酶以及脂蛋白脂肪酶活性的影响。
Effect of diabetes on acid and neutral triacylglycerol lipase and on lipoprotein lipase activities in isolated myocardial cells from rat heart.
作者信息
Ramírez I, Severson D L
出版信息
Biochem J. 1986 Aug 15;238(1):233-8. doi: 10.1042/bj2380233.
A neutral triacylglycerol lipase activity that is separate and distinct from lipoprotein lipase (LPL) could be measured in homogenates of myocardial cells if protamine sulphate and high concentrations of albumin were included in the assay. This neutral lipase was predominantly particulate, with the highest relative specific activity in microsomal subcellular fractions. The induction of diabetes by the administration of streptozotocin to rats resulted in a decrease in LPL activity in myocyte homogenates and in particulate subcellular fractions, but the percentage of cellular LPL activity that was released during incubation of myocytes with heparin was normal. In contrast, neutral lipase activity was increased in diabetic myocyte homogenates and microsomal fractions. Acid triacylglycerol lipase activity was not changed in diabetic myocytes. The decrease in LPL in myocytes owing to diabetes may result in the decreased functional LPL activity at the capillary endothelium of the diabetic heart.
如果在测定中加入硫酸鱼精蛋白和高浓度白蛋白，就可以在心肌细胞匀浆中检测到一种与脂蛋白脂肪酶（LPL）不同且独立的中性三酰甘油脂肪酶活性。这种中性脂肪酶主要存在于微粒体中，在微粒体亚细胞组分中的相对比活性最高。给大鼠注射链脲佐菌素诱导糖尿病，导致心肌细胞匀浆和微粒体亚细胞组分中LPL活性降低，但心肌细胞与肝素孵育期间释放的细胞LPL活性百分比正常。相比之下，糖尿病心肌细胞匀浆和微粒体组分中的中性脂肪酶活性增加。糖尿病心肌细胞中的酸性三酰甘油脂肪酶活性没有变化。糖尿病导致心肌细胞中LPL减少，可能会使糖尿病心脏毛细血管内皮的功能性LPL活性降低。
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