Abnormal Expression And Clinical Significance Of Nitric Oxide (NO) And Nitric Oxide Synthase (NOS) In Patients With Primary Hepatocellular Carcinoma

Objective: To explore the location and expression of inducible nitric oxide synthase(iNOS) in hepatic tissues of the patients with hepatoma, to observe possible relationship between hepatoma occurance and the levels of NO and NOS in sera and liver tissues from these patients ,to investigate the clinical significance of detecting the levels of NO and NOS in the sera of patients with liver disease.Methods: The tissues from different sites (in cancerous foci, paracancerous and away from cancerous foci) of livers of 20 patients with primary hepatocellular carcinoma(PHC) were detected for the distribution and expression of iNOS by immunohistochemistry stain assay, The total RNA contents of liver tissues from those sites were determined by molecular biological method. The activities of NOS and the NO levels in the liver tissue of those patients with hepatoma as well as that in the sera respectively from hepatoma group, benign liver disease group and healthy controls were detected by methods of chemical assay. The diagnosis of 20 PHC cases mentioned aboved was confirmed by histopathological examination. Results: Protein expression of iNOS was negative or weakly positive in the cancerous foci and in the tissues away from it, strongly positive in the paracancerous tissues. The total RNA content, activities of NOS and NO level were significantly higher(P<0.05) in paracancerous tissues than those in the tumors and the distal cancerous tissues, the changes of NOS and NO level in various parts were tendenciously in accordance with that of RNA content. The serum NO and NOS levels were higher in patients with PHC than that in healthy controls(P<0.05), but didn't exbit significant differencebetween PHC group and chronic hepatitis and cirrhosis group. Conclusions: Highly expressing of iNOS was found in liver tissues of cirrhosis. The expression levels of NO and NOS were the highest at paracancerous tissues, just as the result obtained in detecting total RNA content. The NO and NOS level of sera were significantly higher m patients with PHC, hepatic cirrhosis or chrome heptitis than that in healthy controls. The changes of No and NOS levels related to hepatoma occurance. The detection of NO and NOS levels in sera of patients has clinical significance for assistant diagnosis to liver disease, but might have not obvious significance in determining character of liver disease.