| AIM:To investigate the blood pressure lowering and its mechanism of taurine in the fructose-induced insulin resistance and hypertension rats.METHODS:There were 36 male SD rats. They were divided into three groups, such as control group, fructose group and taurine group. The rats in the control group was fed with standard rat chow and had free access to distilled water, while the rats in the fructose group had free access to a high-fructose diet, and the rats in the taurine group had free access to a diet containing high-fructose and received a 2% taurine solution as drinking water. We spent five weeks measuring systolic blood pressure using tail-cuff and weight of rats weekly. Variation range of heart function parameters were observed by using carotid arterial cannulation in anaesthetic rats after injecting noradrenaline by sublingual vein. Insulin, triglycerides and glucose of blood that was collected by abdominal aorta were measured. At the same time, thoracic aorta was isolated and cut into rings. The tone variation of aorta rings affected by noradrenaline, acetylcholine and acidified NaNO2 was observed by using the method of isolated artery rings.RESULTS:(1) Systolic blood pressure of fructose group is significantly higher than that of control group and taurine group (P<0.05). Insulin, triglycerides and glucose of fructose group was significantly higher than of control and taurine group (P<0.05). (2) The variation range of blood pressure and heart rate in taurine group was smaller than in fructose. (3)Noradrenaline (1×10-9～3×10-6mol/L) concentration-dependently contracted the thoracic aortic rings of control, fructose and taurine group. (4) Their logEC50 were -7.53±0.12,-7.42±0.07 and -7.57±0.17 respectively. Their Emax were 3.21±0.21g,3.38±0.17g and 3.15±0.11g. There was Acidified NaNO2 (1×10-10～1×10-4mol/L) concentration-dependently relaxed the rings of control, fructose and taurine pretreated with noradrenaline (1×10-6mol/L). Their logIC50 were -5.85±0.07,-5.71±0.17 and -5.89±0.11 respectively. Their Emax were 90.56±2.38%,95.34±5.17% and 92.48±4.76% respectively. Values of logIC50 and Emax among three groups were not significantly different (P>0.05). (5) Acetylcholine (1×10-10～1×10-5mol/L) concentration-dependently relaxed aorta rings of three groups pretreated with noradrenaline (1×10-6mol/L). Values of logEC50 in three groups were -7.21±0.14,-6.67±0.03 and -7.11±0.09 respectively. Their Emax were 99.28±2.34,80.56±3.21 and 95.65±5.39 respectively. Values of Emax in fructose group were significantly smaller than of control and taurine group (P<0.05). Additionally, value of logIC50 in fructose group was significantly bigger than of control and taurine(P<0.05).CONCLUSION:Taurine significantly decreased hypertension induced by fructose in rats. the possible mechanisms are following. (1) Taurine lower hypertension of fructose-induced rats, because taurine decrease the levels of blood insulin, blood glucose and blood triglycerides. (2) Taurine protect the function of vessel endothelium. as a result of enhancing the creation of endogenous vasodilation materials. (3) To ameliorate baroreflex sensitivity. Moreover, to upgrade the nerve regulation function of blood pressure.
|
PDF Full Text Request