Blanco-Dolado Laura, Martín-Hidalgo Antonia, Herrera Emilio
Servicio de Bioquímica-Investigación, Hospital Ramón y Cajal, Madrid, Spain.
Int J Exp Diabetes Res. 2002;3(1):61-8. doi: 10.1080/15604280212524.
Diabetes mellitus is associated with a reduction of lipoprotein lipase (LPL) activity in adipose tissue and development of hypertriglyceridemia. To determine how a condition of severe insulin deficiency affects mammary gland LPL activity and mRNA expression during late pregnancy, streptozotocin (STZ) treated (40 mg/kg) and non-treated (control) virgin and 20 day pregnant rats were studied. In control rats, both LPL activity and mRNA were higher in pregnant than in virgin rats. When compared to control rats, STZ-treated rats, either pregnant or virgin, showed decreased LPL activity and mRNA content. Furthermore, mammary gland LPL activity was linearly correlated with mRNA content, and either variable was linearly correlated with plasma insulin levels. Thus, insulin deficiency impairs the expression of LPL in mammary glands, revealing the role of insulin as a modulator of the enzyme at the mRNA expression level.
糖尿病与脂肪组织中脂蛋白脂肪酶（LPL）活性降低及高甘油三酯血症的发生有关。为了确定严重胰岛素缺乏状态如何影响妊娠后期乳腺LPL活性和mRNA表达，研究了经链脲佐菌素（STZ）处理（40mg/kg）和未处理（对照）的未孕及妊娠20天的大鼠。在对照大鼠中，妊娠大鼠的LPL活性和mRNA均高于未孕大鼠。与对照大鼠相比，经STZ处理的大鼠，无论妊娠与否，LPL活性和mRNA含量均降低。此外，乳腺LPL活性与mRNA含量呈线性相关，且二者均与血浆胰岛素水平呈线性相关。因此，胰岛素缺乏会损害乳腺中LPL的表达，揭示了胰岛素在mRNA表达水平作为该酶调节剂的作用。
