Effect of prolonged nitric oxide synthesis inhibition on plasma fibrinogen concentration in rats

We examined whether nitro-L-arginine-methyl ester (L-NAME) causes a sustained elevation in plasma fibrinogen concentration in rats. Oral dosing of L-NAME (100 mg/kg per day) for 7 days significantly raised plasma fibrinogen concentration in rats. The increase in plasma fibrinogen, however, returned to control levels by the treatment for more than 7 days, in spite of progressive hypertension. Candesartan failed to reverse the transient hyperfibrinogenemia, indicating that the rise in plasma fibrinogen may occur through the mechanisms other than angiotensin II receptor activation. These data suggest that a prolonged L-NAME treatment does not cause chronic hyperfibrinogenemia in rats.