Studies on serum nitric oxide levels in subjects with high bilirubin value in comparison of normal healthy control subjects

Abstract

Bilirubin is excreted in bile and urine, and elevated levels may indicate certain diseases. Serum bilirubin are inversely related to risk of certain heart diseases. Since nitric oxide (NO) is produced by three types of Nitric Oxide Synthases (NOSs), rapid changes in stable oxidized metabolites (nitrite and nitrate) in the tissues and blood should be represented by the amount of stable forms in serum and may reflect changes in the body. Therefore, the aim of this study was to evaluate the correlation between nitric oxide (nitrite & nitrate) production and bilirubin levels in serum. The serum samples were collected from individuals with high levels of bilirubin and normal range controls. Nitrite was measured by a Griess reaction while nitrate was measured using the enzymatic one step assay with nitrate reductase. The total 36 samples (18 normal range (N) and 18 high bilirubin values (H)) were evaluated for the NO levels. The age group varies from 4-70 & 5-65 for normal & high levels of bilirubin, respectively. The levels of bilirubin in the normal range & high values varies from 0.81-0.98 (mean=0.88+0.01) & 1.12-20.18 (mean=5.96+2.07), respectively. When the nitrite (14.48+1.05μM versus 13.96+0.96μM, P>0.05) and nitrate (25.85+2.04μM versus 25.85+1.53μM, P>0.05) levels were compared between these groups no significant differences were observed. Results of this study reveal that there is no correlation between nitric oxide production and the serum bilirubin levels.