Effects of oral supplementation with glutamate or combination of glutamate and N-carbamylglutamate on intestinal mucosa morphology and epithelium cell proliferation in weanling piglets1

Abstract

To evaluate the effects of glutamate (Glu) or combination of Glu and N-carbamylglutamate (NCG) on intestinal mucosa morphology and epithelium cell proliferation, 18 piglets weaned at 21 d (BW 5.56 ± 0.51 kg) were grouped into 3 treatments and fed one of the following diets for 20 d: a standard diet (SD), SD+Glu(1%), or SD+Glu(1%)+NCG(0.05%). All the piglets were killed for intestinal mucosa collection, and real-time PCR was used to detect mRNA abundance of proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), and β-catenin. The results showed that compared with the control group, adding Glu or Glu+NCG to the diet resulted in a higher villus height and mucosal thickness (P < 0.05) in the jejunum. However, the villus height/crypt depth ratio was unaltered. The RT-PCR results showed that Glu+NCG significantly increased PCNA mRNA abundance in both jejunum and ileum (P < 0.05), while they also significantly increased β-catenin and VEGF mRNA abundance in ileum (P < 0.05). Only Glu increased PCNA mRNA abundance in the jejunum (P < 0.05) and β-catenin mRNA in the jejunum (P < 0.05). These results indicated that oral supply of Glu improved intestinal mucosa morphology, and combined Glu and NCG may have favorable effects on intestinal epithelium cell proliferation than Glu alone.