Impairment of L-arginine metabolism in spontaneously hypertensive rats.

Plasma L-arginine concentrations were determined in spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY) before and after water immersion stress. There was no difference in the plasma levels of L-arginine before stress loading between SHR and WKY rats. A significant decrease in the L-arginine level was found in the adult SHR rats after the stress stimuli. However, there was no change in plasma levels of L-arginine in the adult WKY rats before and after water immersion stress. In the weanling rats, significant increases were observed in the plasma L-arginine levels after stress loading in both strains. These findings indicate that there may be an impairment of the L-arginine metabolism in the SHR rats with age and that it may involve in the genesis of hypertension in the SHR rat through the L-arginine-EDRF system.