Abstract
The objective of the current study is to evaluate the effects of dietary supplementation with arginine (ARG), N-carbamylglutamate (NCG), and glutamine (GLN) on rat intestinal morphology and antioxidant status under oxidative stress. Rats were fed for 30 d with one of the following iso-nitrogenous diets: basal diet (BD), BD plus 1% ARG, BD plus 0.1% NCG, and BD plus 1% GLN. On day 28, half of the rats fed BD were intraperitoneally injected with 12 mg/kg body weight of diquat (DT; i.e., the DT group) and the other half was intraperitoneally injected with sterile solution (i.e., the control group). The other diet groups were intraperitoneally injected with 12 mg/kg body weight of DT (i.e., DT + 1% GLN [DT + GLN], DT + 1% ARG [DT + ARG], and DT + 0.1% NCG [DT + NCG]). Rat jejunum samples obtained at 48 h after DT injection were analyzed. Results showed that DT significantly decreased catalase (CAT) activity and glutathione (GSH) content by 58.25% and 56.57%, respectively, and elevated malondialdehyde (MDA) content and crypt depth (CD) by 19.39% and 22.13%, respectively, in the jejunum (P P P P P P < 0.05). Collectively, this study suggested that dietary supplementation with 1% GLN, 0.1% NCG, and 1% ARG was effective in enhancing the antioxidant status and maintaining the morphological structure of rat jejunum under oxidative stress; of these supplements, 1% GLN exerted the greatest effects on mitigating oxidative stress.