Martin-Hidalgo A, Holm C, Belfrage P, Schotz M C, Herrera E
Department of Medical and Physiological Chemistry, University of Lund, Sweden.
Am J Physiol. 1994 Jun;266(6 Pt 1):E930-5. doi: 10.1152/ajpendo.1994.266.6.E930.
To investigate the factors controlling maternal depot fat accumulation during early pregnancy and net decrease during late pregnancy, the activity and mRNA expression of adipose tissue lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) were related to several other lipid metabolic parameters. Virgin control rats, pregnant rats (at days 12, 15, 19, and 21), and lactating rats (at days 5 and 10 postpartum) were studied. In adipose lumbar tissue of late pregnant rats, LPL activity decreased to about one-third that of the virgin control animals, with < 10% of initial LPL mRNA expressed as determined by Northern blots. HSL activity increased maximally 1.5-fold with a fourfold increase of HSL expression at days 12-15 of pregnancy and decreased to control levels after parturition. The HSL-to-LPL mRNA and activity ratios were enhanced from days 15 and 19 of pregnancy, respectively, and remained so even during lactation, mainly because of the marked lowering of the LPL values. This enhancement coincided with increments in plasma free fatty acids and glycerol levels indicating an increased depot fat breakdown. These results give no indication of an involvement of LPL and HSL gene expression changes in the accumulation of maternal depot during early pregnancy. In contrast, such changes could be responsible for the net breakdown of this fat depot during late gestation. Thus, during this physiological state, long-term (e.g., transcriptional) regulation of LPL and HSL gene expression could be an important mechanism for the control of adipose tissue mass breakdown during late gestation.
为研究妊娠早期母体储存脂肪积累及妊娠晚期净减少的控制因素，将脂肪组织脂蛋白脂肪酶（LPL）和激素敏感性脂肪酶（HSL）的活性及mRNA表达与其他几个脂质代谢参数进行关联研究。对未孕对照大鼠、妊娠大鼠（妊娠第12、15、19和21天）及泌乳大鼠（产后第5和10天）进行了研究。在妊娠晚期大鼠的腰部脂肪组织中，LPL活性降至未孕对照动物的约三分之一，Northern印迹法测定显示初始LPL mRNA的表达量不到10%。HSL活性在妊娠第12 - 15天最大增加1.5倍，HSL表达增加四倍，产后降至对照水平。妊娠第15天和19天起，HSL与LPL的mRNA及活性比值分别升高，即使在泌乳期也保持如此，主要是因为LPL值显著降低。这种升高与血浆游离脂肪酸和甘油水平的升高同时出现，表明储存脂肪分解增加。这些结果未显示LPL和HSL基因表达变化参与妊娠早期母体储存脂肪的积累。相反，这种变化可能是妊娠晚期该脂肪储存净分解的原因。因此，在这种生理状态下，LPL和HSL基因表达的长期（如转录）调控可能是妊娠晚期控制脂肪组织质量分解的重要机制。
