mpaired vasodilatation in response to acetylcholine [33]
or bradykinin [34] and a state of proinflammatory and
prothrombotic endothelium due to reduced endothelium-
derived NO (EDNO). This is explained by the function of
EDNO that mediate endothelium dependent vasodilata-
tion, anti-inflammatory and antithrombotic effects [35,36].
In vascular diseases mainly hypertension, the vascular
relaxation and vasodilatation function of endothelium is
suppressed and sometimes abolished when atheroscler-
osis takes place [34]. Therefore it is postulated that se-
vere hypertensive rats will manifest low level of NO.
When NO level is increased, vasodilatation takes place