AimTo investigate the effects of glycine on endothelial function in rats with a high-fructose diet induced hypertension and the mechanisms of glycine on lowering hypertension.MethodsModel group rats were fed with 8% fructose water, and glycine intervention group rats were fed with water containing 8% fructose and 1% glycine.The body weight and systolic blood pressure were measured monthly, and the animals were killed in 4 th month and 8 th month respectively.The levels of plasma glucose, insulin, endotoxin, TNF-α, IL-6, NO and endothelin-1 (ET-1) were detected, and HOMA-IR was calculated.The expression of endothelial nitric oxide synthase (eNOS) was determined by immunohistochemistry, and the expression of endothelin A receptor (ETA-R) mRNA was analyzed by RT-PCR.ResultsThe body weight and systolic blood pressure were increased in model group after 3 months.The levels of plasma glucose, insulin, HOMA-IR, endotoxin, pro-inflammatory cytokines, ET-1 and the expression of ETA-R mRNA were increased in model group, but the levels of plasma NO and the expression of eNOS were decreased in 4 th and 8 th month.However, there was no significance of the parameters at different stages.Glycine significantly reduced the weight gain at 4 th month and 6 th month, and reduced the elevated systolic blood pressure in 4 th month to 6 th month, and significantly decreased the levels of plasma insulin, HOMA-IR, endotoxin, pro-inflammatory cytokine, ET-1 and the expression of ETA-R mRNA in 4 th and 8 th month, and significantly increased the levels of plasma NO and the expression of eNOS in 4 th month.ConclusionsGlycine can ameliorate early hypertension induced by a high-fructose diet, which may be related