Effects of L-arginine on blood pressure and metabolic changes in fructose-hypertensive rats.
In the present study, we examined the effects of chronic L-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). L-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 L-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, L-arginine treatment of F rats prevented the increased glucose and insulin concentrations in response to oral glucose challenge. L-arginine treatment also prevented the decrease in insulin sensitivity of F rats. These results indicate that L-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 L-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.
Tay
Aydin
A
Department of Pharmacology, Faculty of Pharmacy, Ankara University, Turkey.
Ozçelikay
A Tanju
AT
Altan
V Melih
VM
D000818:Animals; D001120:Arginine / Q000494:pharmacology*; D001786:Blood Glucose / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects*; D004734:Energy Metabolism / Q000187:drug effects*; D005632:Fructose / Q000494:pharmacology*; D006946:Hyperinsulinism / Q000378:metabolism; D006973:Hypertension / Q000378:metabolism*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D014280:Triglycerides / Q000097:blood
D001786:Blood Glucose; D007328:Insulin; D014280:Triglycerides; D005632:Fructose; D001120:Arginine