Knopp R H, Boroush M A, O'Sullivan J B
Metabolism. 1975 Apr;24(4):481-93. doi: 10.1016/0026-0495(75)90073-6.
Plasma postheparin lipolytic activity (PHLA) has been measured in rat pregnancy to qualitatively assess mechanisms of triglyceride removal from the circulation. This assessment can be made if the larger plasma volume of pregnancy is considered. A supramaximal dose of heparin avoids dilution of the heparin stimulus to PHLA release. Dilution of the released PHLA is corrected using measurements of plasma volume. In addition, no evidence of circulating inhibitors is present, and timing of PHLA appearance is unaffected by pregnancy. Prior studies of postheparin lipolytic activity in human pregnancy have not taken the effect of plasma volume into account and must therefore be reconsidered in light of the present results. We observed a biphasic pattern in PHLA over the course of gestation. Levels were increased in midgestation (day 12), declined to normal by day 19, and fell rapidly to one-half of control by day 21. Assuming a functional role for the triglyceride lipases represented in PHLA, the data suggest the following hypothesis: triglyceride removal is increased or normal for the greater part of gestation and is decreased only at term. If this hypothesis proves true, the hypertriglyceridemia of pregnancy should be due largely to overproduction, with decreased removal contributing only near term.
已对大鼠孕期的血浆肝素后脂解活性（PHLA）进行了测量，以定性评估从循环中清除甘油三酯的机制。如果考虑到孕期血浆量增加，就可以进行这种评估。超最大剂量的肝素可避免肝素刺激对PHLA释放的稀释。使用血浆量测量值来校正释放的PHLA的稀释。此外，不存在循环抑制剂的证据，且PHLA出现的时间不受孕期影响。先前关于人类孕期肝素后脂解活性的研究未考虑血浆量的影响，因此必须根据目前的结果重新考虑。我们在整个孕期观察到PHLA呈双相模式。在妊娠中期（第12天）水平升高，到第19天降至正常，到第21天迅速降至对照值的一半。假设PHLA中所代表的甘油三酯脂肪酶具有功能性作用，这些数据提示了以下假设：在孕期的大部分时间里，甘油三酯清除增加或正常，仅在足月时降低。如果这个假设被证明是正确的，孕期的高甘油三酯血症应主要归因于过量产生，仅在临近足月时清除减少起作用。
