Dietary L-arginine supplementation can increase the vascular endothelial growth factor(VEGF) and HSP70 expression in weaned pigs

摘要

This study was conducted to evaluate the effects of dietary arginine on expression of VEGF and HSP70 in weaned pigs. Twenty 21-d-old crossbred pigs (5.3 ± 0.13 kg body weight) were individually housed and randomly allotted to 1 of 2 diets supplemented with 0 and 1% L-arginine (10 pigs per group). Following a 7-d period of arginine supplementation, 6 pigs from each group were randomly selected and humanely killed for tissue sample collection. The expression of VEGF in intestine was determined by immuno-histochemistry and HSP70 in liver was tested by real-time PCR, western blot and immuno-histochemistry. Compared with control pigs, dietary supplementation with 1% L-arginine increased (P < 0.05) average daily gain (ADG) and decreased (P < 0.05) feed/gain ratio. Supplementation with 1% L-arginine increased (P <0.05) the villus height throughout the small intestine compared with the controls. Crypt depth was greater in the duodenum and jejunum of the control group compared with those supplemented with 1% L-arginine (P<0.05). Dietary supplementation with 1% L-arginine also increased (P<0.05) immunoreactive expression of vascular endothelial growth factor (VEGF) in duodenal submucosa, jejunal mucosa and submucosa, and ileal mucosa, and also increased HSP70 mRNA expression in liver (P<0.05) compared with the control. Collectively, these findings indicate that arginine supplementation can improve the growth of weaned pigs by enhancing intestine development and ability of anti-stress. Moreover, dietary supplementation with 1% L-arginine may be a useful method to improve growth performance of weaned pigs.