title: Effects of glutamine supplementation on oxidative stress-related gene expression and antioxidant properties in rats with streptozotocin-induced type 2 diabetes.
abstract: There are close links among hyperglycaemia, oxidative stress and diabetic complications. Glutamine (GLN) is an amino acid with immunomodulatory properties. The present study investigated the effect of dietary GLN on oxidative stress-relative gene expressions and tissue oxidative damage in diabetes. There were one normal control (NC) and two diabetic groups in the present study. Diabetes was induced by an intraperitoneal injection of nicotinamide followed by streptozotocin (STZ). Rats in the NC group were fed a regular chow diet. In the two diabetic groups, one group (diabetes mellitus, DM) was fed a common semi-purified diet while the other group received a diet in which part of the casein was replaced by GLN (DM-GLN). GLN provided 25% of total amino acid N. The experimental groups were fed the respective diets for 8 weeks, and then the rats were killed for further analysis. The results showed that blood thioredoxin-interacting protein (Txnip) mRNA expression in the diabetic groups was higher than that in the NC group. Compared with the DM group, the DM-GLN group had lower glutamine fructose-6-phosphate transaminase 1, a receptor of advanced glycation end products, and Txnip gene expressions in blood mononuclear cells. The total antioxidant capacity was lower and antioxidant enzyme activities were altered by the diabetic condition. GLN supplementation increased antioxidant capacity and normalised antioxidant enzyme activities. Also, the renal nitrotyrosine level and Txnip mRNA expression were lower when GLN was administered. These results suggest that dietary GLN supplementation decreases oxidative stress-related gene expression, increases the antioxidant potential and may consequently attenuate renal oxidative damage in rats with STZ-induced diabetes.
authors: School of Nutrition and Health Sciences, Taipei Medical University, 250 Wu-Hsing Street, Taipei 110, Taiwan, ROC.
authors: Pei-Hsuan
authors: PH
authors: Tsai
authors: Jun-Jen
authors: JJ
authors: Liu
authors: Chui-Li
authors: CL
authors: Yeh
authors: Wan-Chun
authors: WC
authors: Chiu
authors: Sung-Ling
authors: SL
authors: Yeh
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage* / Q000378:metabolism; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics; D018797:Cell Cycle Proteins; D017931:DNA Primers / Q000235:genetics; D003921:Diabetes Mellitus, Experimental / Q000097:blood / Q000178:diet therapy* / Q000235:genetics; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000178:diet therapy / Q000235:genetics; D019587:Dietary Supplements; D004912:Erythrocytes / Q000378:metabolism; D015870:Gene Expression / Q000187:drug effects*; D005973:Glutamine / Q000008:administration & dosage*; D005978:Glutathione / Q000097:blood; D007668:Kidney / Q000378:metabolism; D008297:Male; D018384:Oxidative Stress / Q000187:drug effects; D012333:RNA, Messenger / Q000097:blood / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism
chemical_list: D000975:Antioxidants; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D017931:DNA Primers; D012333:RNA, Messenger; C493796:TXNIP protein, rat; D005973:Glutamine; C002744:3-nitrotyrosine; D014443:Tyrosine; D005978:Glutathione