新生仔猪肝脏发育的肝细胞生化分析

Studies on the Developmental Pattern of Pig Liver during Neonatal Period

选择新生仔猪15头,分别于出生当日(0 d)、出生后3 d及7 d屠宰取样,制作肝脏电镜切片进行组织学分析,并测定肝脏中DNA、RNA含量及常规生化指标.结果显示:新生仔猪肝细胞中内质网、线粒体等细胞器都很丰富,而且各细胞器的结构已经发育成熟.肝脏质量在仔猪出生后1周尤其是3 d内迅速增加(P＜0.01),远远快于体重增加的速度.仔猪肝脏的蛋白质含量在生后1周也迅速增加(P＜0.01);而肝糖原贮备在刚出生时较高,出生后迅速下降(P＜0.01).仔猪出生后肝脏中DNA和RNA浓度的变化趋势正好相反,前者在出生后3 d内明显下降(P＜0.05),4～7 d又有增加趋势,而RNA浓度以3 d为最高.试验结果表明,仔猪到出生时肝细胞的结构和功能基本发育成熟.仔猪出生以后,肝脏的生长发育十分迅速,不仅肝细胞的数量快速增加,肝细胞的体积也不断增大.

The aim of this study was to explore the develompental pattern of liver during neonatal period.Fifteen neonatal pigs were killed and sampled on newborn(day 0),day 3 and day 7 after birth,respectively.A portion of liver tissue was taken for transmission electron microscopic examination.Such biochemical indices as DNA,RNA and liver glycogen were analyzed according to appropriate methods.The hepatocyte cords were arranged in a radial mode and there were abundant mature cellular organelles such as mitochondria and rough endoplasmic reticula in the liver of neonatal pigs.Liver weight increased at a higher rate than body weight in the first 7 days,especially in the first 3 days after birth.Similarly,liver protein content increased significantly in the first postnatal week(P<0.01).In contrast,liver glycogen content was highest at birth and decreased markedly after birth(P<0.01).DNA concentration was lowest(P<0.05) and RNA concentration highest (P<0.05) in the liver of 3-day old piglets.In conclusion,the hepatocytes of piglets had already developed both in structure and in function at birth.Both the size and the number of hepatocytes increased greatly,and therefore liver grows quickly during the short period after birth.