There is increasing evidence that alterations in nitric oxide synthesis are of pathophysiological importance in heart diseases. So, the present study was conducted to evaluate the role of inducible nitric oxide synthase (iNOS) in coronary heart diseases either is-chemic heart disease (IHD) or myo-cardial infarction (Mi) and to detect the expression of iNOS gene in these diseases. The current study was con­ducted on 50 patients (25 patients with ischemic heart disease and 25 patients with myocardial infarction) with mean age 55.53 ± 4.18 years and 12 healthy volunteers of matched age and sex were taken as control.
The serum levels of nitrite and cGMP were measured by spectropho-tometric method and ELISA assay, re­spectively and also detection of the
iNOS gene expression in the total RNA extracted from different studied groups were done. Results of the present study have demonestrated that: a significant increase in nitrite and cGMP levels in myocardial infarc­tion group compared to control group. Anon-significant increase in nitrite and cGMP levels in myocardial infarction group compared to control group. Anon-significant increase in nitrite and cGMP levels in ischemic heart dis­ease group compared to control group. Also, iNOS gene expression was found to be positive in 76% of myocardial infarction group and nega­tive in ischemic heart disease group. Positive correlation between serum nitrite and serum cGMP in all patients groups. Also, positive correlation be­tween serum nitrite, serum cGMP and iNOS gene expression. So, in conclu­sion, iNOS may have a role in the pa-329