孕期边缘性维生素A缺乏对新生大鼠VA营养及LRAT的影响

Neonatal vitamin A and LRAT is affected in marginal vitamin A deficiency rats

目的:探讨孕期边缘性维生素A缺乏(Marginalvitamin Adeficiency,MVAD)对胎鼠维生素A(VitaminA,VA)营养及VA储存关键酶:卵磷脂视黄醇酰基转移酶(Lecithin retinol acyltransferase,LRAT)的影响。方法:16只健康成年雌性Wistar大鼠(260～300g)随机分为正常对照(Control)组和MVAD组,每组8只,成功制备上述模型后,与正常雄性Wistar大鼠合笼。收集孕鼠和胎鼠血清、肝脏组织。采用高效液相色谱法测定VA含量;分别采用RT-PCR和Western blot技术检测肝脏LRAT在mRNA水平和蛋白水平上的变化。结果:MVAD组孕鼠,胎鼠血清VA,肝脏VA明显低于正常对照组,差异有统计学意义(P<0.001);同时,相对于Control组,MVAD组LRATmRNA和蛋白水平明显下调(P<0.001)。结论:孕期MVAD,胎鼠的血清维生素A水平明显下降,不能满足肝脏VA储存。血清VA水平不能很好地反映机体VA营养的真实水平,肝脏VA含量更能准确反映机体VA含量。LRAT在维生素A储存过程中起着关键作用。

Objective：To investigate the effect of neonatal vitamin Aand LRAT in marginal vitamin Adeficiency（MVAD）rats during pregnancy.Methods：Sixteen adult female Wistar rats were randomly separated into control and MVAD groups （eight per group）.Serum and livers from mothers and new borns were collected after the establishment of the above two animal models.The vitamin A level was analyzed by HPLC.RT-PCR and Western blot analysis were used to assay the transcriptional level and protein level of LRAT in neonatal liver.Results：The plasma and liver vitamin A level from maternal and neonatal was significantly lower in the MVAD compared to the control group （P0.001）Meanwhile,LRAT mRNA and protein level were down-regulated （P0.001）.Conclusion：In the absence of dietary vitamin A from pregnancy,a normal level of plasma retinol alone was not enough to support body vitamin A storage.We can also conclude from our data that LRAT plays a crucial role in vitamin A storage.