Heat Shock Protein 70 Expression is Increased in the Liver of Neonatal Intrauterine Growth Retardation Piglets

Intrauterine growth retardation (IUGR) leads to the dysfunction in digestive system, as well as the alteration in the expression of some functional proteins. Heat shock protein 70 (Hsp70) could be induced by various stress factors, but whether Hsp70 expression is changed in neonatal IUGR infants has not been demonstrated. This study was conducted to explore the expression of Hsp70 in the liver by using the IUGR piglet model. Liver and plasma samples were obtained from IUGR and normal birth weight (NBW) piglets at birth. The neonatal IUGR piglets had significantly lower liver weight than their counterparts. The activities of aspartate aminotransferase and alanine aminotransferase in serum were enhanced significantly in IUGR indicating liver dysfunction. The activities of superoxide dismutase (p<0.01), glutathione peroxidase (p<0.01) and catalase (p>0.05) were lower and the level of malondialdehybe was higher (p<0.05) in IUGR liver compared with in NBW. According to the results of histological tests, fatty hepatic infiltrates and cytoplasmic vacuolization were present in the liver of IUGR piglets, but not in NBW liver. The expression of Hsp70 protein was significantly higher (p<0.05) in IUGR piglet liver than in NBW. Similar to where the hepatic injuries were observed, location of Hsp70 was mostly in the midzonal hepatic lobule indicating that oxidative stress might be responsible for the increased expression of Hsp70.