Effect of supplemental L-arginine on the function of T lymphocytes and the formation of advanced glycosylated end products in rats with streptozotocin-induced diabetes.
OBJECTIVE
We investigated the effect of supplemental L-arginine on lymphocyte function in diabetes and its association with suppressed formation of advanced glycosylated end products (AGEs).


METHODS
For the in vivo study, rats with streptozotocin-induced (65 mg/kg of body weight, intravenously) diabetes were treated with or without 2% L-arginine or glycine (as a positive control) in drinking water for 8 wk. We then measured serum fructosamine concentrations and concanavalin A-induced proliferative ability of lymphocytes from these animals. For the in vitro study, AGEs derived from albumin were prepared by incubating D-glucose (200 mmol/L) and bovine serum albumin (100 mg/mL) at 37 degrees C for 2 wk in the presence or absence of L-arginine (0.1-10 mmol/L). These preparations were quantified for their bovine serum albumin--derived AGE content, and their effect on concanavalin A-induced proliferative activity of T lymphocyte from normal rats was measured.


RESULTS
Serum fructosamine concentrations were significantly higher in the diabetic rats than in the control rats (P<0.05) but were significantly lowered with L-arginine supplementation (P<0.05). The lower lymphocyte proliferation rate found in the diabetic rats was reversed by supplemental L-arginine (P<0.05). During the course of incubation of bovine serum albumin with D-glucose, the presence of L-arginine prevented the formation of bovine serum albumin-derived AGEs and attenuated their inhibitory effect on the rate of lymphocyte proliferation in a dose-dependent manner.


CONCLUSIONS
Supplemental L-arginine improved the function of T lymphocytes in diabetic rats in association with decreased formation of AGEs.
Liu
Cheng-Tzu
CT
Department of Nutrition, Chung Shan Medical University, Taichung, Taiwan, Republic of China. ctl@csmu.edu.tw
Chen
Ke-Ming
KM
Lee
Shwu-Huey
SH
Tsai
Ling-Jane
LJ
D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000494:pharmacology*; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D004306:Dose-Response Relationship, Immunologic; D019270:Fructosamine / Q000097:blood / Q000378:metabolism; D017127:Glycation End Products, Advanced / Q000378:metabolism*; D005998:Glycine / Q000008:administration & dosage / Q000494:pharmacology; D006031:Glycosylation; D008213:Lymphocyte Activation / Q000187:drug effects / Q000502:physiology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013601:T-Lymphocytes / Q000187:drug effects / Q000502:physiology*
D017127:Glycation End Products, Advanced; D019270:Fructosamine; D001120:Arginine; D005998:Glycine