The optimal infusion rate of medium-chain triglyceride/long-chain triglyceride emulsion (MCT/LCT) during plasma insulin clamp

由于中链甘油三酯乳剂(MCT)比长链甘油三酯乳剂(LCT)更快地被水解，所以MCT/LCT的输注速度往往比LCT快。本研究的目的是确定MCT/LCT稳定甘油三酯(TG)血药浓度的最佳输注速度，相当于乳剂的最佳输注速度。通过提高平均([]sy.+-)建立TG钳夹。甘油三酯在血浆中的浓度为1.08()sy.+-。[)LCT的增量-；[]每种乳剂预注50min后，MCT/LCT的增量为0.31-mmol/L。此后，每10min控制一次脂质输注速度，以维持稳定的甘油三酯浓度150min。试验期内持续输注葡萄糖0.32g/kg/h。以重量为基础的输液维持血浆甘油三酯浓度稳定的比率在中长春和长春新秀之间没有差别，为0.125(SY+-)。[)0.013比0.117([正负])。[]0.021 g/kg/h，摩尔基输液速率为0.203(sy.+-)。MCT/LCT为0.021 mmoL/kg/h，Sy.+-为0.132。这些结果表明，尽管在恒定输液过程中，MCT/LCT的摩尔水解率可以增加54%，但在稳定状态下，MCT/LCT的输注速度不应超过0.1g/kg/h。载脂蛋白C-II(ApoC-II)是甘油三酯(TG)水解所必需的。结果表明，MCT和LCT从高密度脂蛋白到脂质颗粒的体外转移量没有差异，但MCT-TGS在水解过程中需要的apo C-II比LCT少，因为MCT-TG 1微摩尔获得的apo C-II量比LCT-TG少。

As medium-chain triglyceride emulsions (MCT) are more rapidly hydrolyzed than long-chain triglyceride emulsions (LCT), MCT/LCT tends to be infused faster than LCT.The purpose of this research project was to determine the most appropriate infusion rate for MCT/LCT to stabilize plasma concentrations of triglyceride (TG), being equivalent to the optimal infusion rate of the emulsion. A TG clamp was set up by raising the mean (]SY.+-。[) s.d.concentrations of TG in plasma, being 1.08 (]SY.+-。[) 0.18 delta-mmol/l for LCT,and 1.65 (]SY.+-。[) 0.31 delta-mmol/l for MCT/LCT after a 50-min priming infusion of each emulsion. Thereafter, the infusion rate of lipid was controlled every 10 min to maintain a steady concentration of TG for a period of 150 min. A constant infusion of glucose at 0.32 g/kg/h was given for the test period. The weight-based rate of the infusion to maintain a steady state of plasma TG concentrations did not differ between MCT/LCT and LCT,being 0.125 (]SY.+-。[) 0.013 versus 0.117 (]SY.+-。[) 0.021 g/kg/h, while the molar-based infusion rate was 0.203 (]SY.+-。[) 0.021 mmol/kg/h for MCT/LCT and 0.132 (]SY.+-。[) 0.023 mmol/kg/h for LCT.These results suggest that although 54% more molar MCT/LCT can be hydrolyzed during a constant infusion, MCT/LCT should not be infused at a rate faster than 0.1 g/kg/h under a steady state.Apolipoprotein C-II (apo C-II) is essential for TG hydrolysis. It was investigated in vitro if the amounts of apo C-II acquired by lipid particles are different between MCT and LCT.The results demonstrated that there was no differences in the amounts of in vitro transfer of apo C-II from high-density lipoprotein to lipid particles between MCT and LCT.However, it was suggrested that MCT-TGs require less amounts of apo C-II than LCT in the process of hydrolysis, since the mean amount of apo C-II acquired by one micro-mol of MCT-TG was less than that acquired by one micro-mol of LCT-TG.