Effect of prolonged nitric oxide synthesis inhibition on plasma fibrinogenconcentration in rats

We examined whether nitro-L-arginine-methyl ester (L-NAME) causes a sustain ed elevation in plasma fibrinogen concentration in rats. Oral dosing of L-N AME (100 mg/kg per day) for 7 days significantly raised plasma fibrinogen c oncentration in rats. The increase in plasma fibrinogen, however, returned to control levels by the treatment for more than 7 days, in spite of progre ssive hypertension. Candesartan failed to reverse the transient hyperfibrin ogenemia, indicating that the rise in plasma fibrinogen may occur through t he mechanisms other than angiotensin LI receptor activation. These data sug gest that a prolonged L-NAME treatment does not cause chronic hyperfibrinog enemia in rats.