Experimental study of myocardial injury induced by total parenteral nutrition in young rats

Objective To investigate the effect and mechanism of total parenteral nutrition (TPN) on the myocardial injury of young rats. Methods Twenty-four male young Sprague-Dawley rats aged 6 to 8 weeks were randomly divided into 4 groups (6 each): normal group, control group, TPN-7 d group and TPN-14 d group. Rats in normal group were not placed into tubes and had free food and water. Rats in control group were catheterized through the right jugular vein and continuously infused with normal saline, free food and water. Those in TPN group were catheterized through the right jugular vein and continuously infused with TPN nutrient solution and abstained from food and water. Rats in the 4 groups were killed and their myocardial tissue were obtained on the 14th, 14th, 7th and 14th day after the establishment of the model, respectively. HE staining was performed to observe the pathological changes of myocardial tissue, TUNEL staining was used to observe the apoptosis of myocardial tissue, the contents of malondialdehyde (