Effects of -arginine on blood pressure and metabolic changes in fructose-hypertensive rats

Abstract In the present study, we examined the effects of chronic -arginine treatment on plasma insulin levels and systolic blood pressure (SBP) in fructose-fed (F) rats. Fructose feeding resulted in hyperinsulinemia and elevated blood pressure when compared with that in controls (plasma insulin, 311.3 ± 11.4 v control 164.4 ± 11.8 pmol/L, P< .05; SBP, 135.4 ± 4.2 v control 105.5 ± 1.3 mm Hg, P< .05). -arginine treatment of fructose-hypertensive rats prevented the development of hyperinsulinemia and hypertension (plasma insulin, 200.1 ± 7.5 pmol/L; P< .05 compared with that in F rats; SBP, 108.0 ± 0.9 mm Hg; P< .05 compared with F rats). However, treatment with -arginine did not influence any of these parameters in control rats. Statistical analysis of the data of plasma insulin level and SBP, revealed a significant correlation between these two variables. On the other hand, -arginine treatment of F rats prevented the increased glucose and insulin concentrations in response to oral glucose challenge. -arginine treatment also prevented the decrease in insulin sensitivity of F rats. These results indicate that -arginine treatment is able to prevent fructose-induced hypertension and hyperinsulinemia. Our data also suggest a strong relationship between hyperinsulinemia and hypertension in this hypertensive rat model. Therefore, the antihypertensive effect of -arginine could be, at least in part, the result of the restoration of plasma insulin levels by its vasodilator ability to increase blood flow to insulin sensitive tissues.