蓝塘仔猪IGF-1水平与组织IGF-1、GHR基因的表达

32头不同日龄(出生、3、21、35d)蓝塘仔猪,由前腔静脉采血后剖杀,取肝脏、背最长肌样品。用RIA法测血液、组织中IGF 1浓度,用放射受体法(RBA)检测肝脏、肌肉组织中GHR结合活性,用实时荧光定量PCR法检测IGF 1、GHRmRNA的表达水平。结果表明:(1)血液中IGF 1在出生日显著高于其它时期(P<0 05)。肌肉组织中IGF 1含量高于肝脏组织,肌肉组织IGF 1含量在3、21、35日龄时都显著高于出生日(P<0 05)。(2)肝脏细胞膜GHR结合活性在出生日显著高于3、21日龄(P<0 05),肝脏细胞膜GHR结合活性高于肌肉组织。(3)肝脏组织IGF 1、GHRmRNA的表达量均显著高于肌肉组织(P<0 05)。肝脏IGF 1mRNA的表达在出生日、21日龄时显著高于3、35日龄(P<0 05),GHRmRNA的表达在出生日显著高于其它日龄(P<0 05)。肌肉IGF 1、GHRmRNA的表达在出生日均显著高于其它日龄(P<0 05)。

Expression of IGF-1 and GHR in Tissue and IGF-1 Concentrations of Lantang Piglets

Thirty-two purebred Lantang piglets of the same age derived from multiparous sow were slaughtered at the newborn, 3, 21 and 35 d of age respectively. Blood sample and tissues samples including liver and longissimus muscle were collected each time. Concentrations of IGF-1 in serum and in liver and muscle were determined by radio-immunoassay (RIA). Growth hormone receptor (GHR) specific binding activity in the membrane of liver cell and in muscle cell was determined by the method of radioligand binding assay(RBA). Real-time polymerase chain reaction (PCR) quantifications of IGF-1 mRNA and GHR mRNA from liver, muscle were carried out by DNA binding dye method using SYBR Green PCR Core Reagents Kit in Rotor-gene 2 000 Real-time Cycler. The results showed that: 1. Serum IGF-1 levels of newborn piglets were significantly higher than any other days observed (P<0.05).Concentrations of IGF-1 in longissimus muscle were higher than in liver per micrograms protein, longissimus muscle IGF-1 levels were higher at 3, 21 and 35 d than that of newborn (P<0.05).2. Growth hormone receptor (GHR) specific binding activity in the membrane of liver cell was highest at newborn (P<0.05). Growth hormone receptor (GHR) specific binding activity in the membrane of liver cell was higher than in the membrane of longissimus muscle cell.3.IGF-1 and GHR mRNA levels in liver were significantly higher than longissimus muscle (P<0.05). Liver IGF-1 mRNA levels in newborn and 21 d were significantly higher than 3 d and 35 d(P<0.05). Liver GHR mRNA levels of newborn were significantly higher than any other days observed (P<0.05). Longissimus muscle IGF-1 and GHR mRNA levels of newborn were significantly higher than any other days observed (P<0.05).