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目的探讨哺乳期营养过剩与肝脏线粒体改变及脂质代谢的关系。方法 ICR品系孕鼠分娩后D5,通过调整每窝子鼠数量,建立出生后哺乳期营养过剩动物模型。每只母鼠哺乳10只子鼠设为对照组(CTR),调整后每只母鼠哺乳3只子鼠设为哺乳期营养过剩组(LON)。21 d处死子鼠取肝脏,采用透射电镜技术观察肝细胞线粒体改变,HE染色观察肝组织形态学改变,实时荧光定量PCR检测动物肝脏组织肉碱酯酰转移酶-1(CPT-1)、硬脂酰辅酶A去饱和酶-1(SCD-1)及脂肪酸合成酶(FASN)mRNA表达水平,Western blot检测肝脏中CPT-1和细胞色素C(Cyt-C)的蛋白表达。结果哺乳期营养过剩可以导致子代肥胖(P<0.001),肝脏组织脂质沉积明显,SCD-1和FASN基因表达水平升高(P<0.01),肝细胞出现线粒体肿胀,并伴有CTP-1基因和蛋白水平表达降低(P<0.01),细胞色素C表达降低(P<0.01)。结论哺乳期营养过剩能促进肝脏脂质沉积,该作用可能与肝细胞线粒体功能改变、脂肪酸β-氧化水平降低及脂质合成增多有关。哺乳期营养过剩可能是诱发成年期脂肪肝的重要危险因素。[营养学报,2012,34(6):540-544]
Objective To investigate the relationship between excess nutrients during lactation and liver mitochondrial changes and lipid metabolism. Methods ICR strains of pregnant rats D5 after delivery, by adjusting the number of litter per litter, the establishment of postnatal lactation over-fed animal model. 10 females were fed as control group (CTR), and 3 females were fed lactation group (LON). The rats were sacrificed on day 21 and the liver was taken. The changes of mitochondria of hepatocytes were observed by transmission electron microscopy. The morphological changes of liver were observed by HE staining. The contents of carnitine acyltransferase-1 (CPT-1) The mRNA expression of SCD-1 and FASN was detected by Western blot. The protein expression of CPT-1 and Cyt-C in the liver were detected by Western blot. Results The over-nutrition during lactation could lead to obesity in offspring (P <0.001), lipid deposition in liver tissues, increased expression of SCD-1 and FASN gene (P <0.01), mitochondria swelling in hepatocytes and CTP- 1 gene and protein expression decreased (P <0.01), cytochrome C expression decreased (P <0.01). Conclusions Excessive nutrition during lactation can promote hepatic lipid deposition, which may be related to changes of mitochondria function of liver cells, decrease of β-oxidation of fatty acid and increase of lipid synthesis. Over-nutrition during lactation may be an important risk factor for inducing fatty liver in adulthood. [Journal of Nutrition, 2012,34 (6): 540-544]