Study on the serum arginase and nitrate levels in association with Fev1/Fvc ratio in chronic obstructive pulmonary disease

Abstract

COPD is generally associated with chronic inflammation in peripheral airway and lung parenchyma which finally leads to obstruction of the airways. The diagnostic criteria for COPD is FEV1/FVC ratio which is less than 0.7. Arginase being the key enzyme of urea cycle, is also expressed in extra hepatic tissue including lung in the bronchial epithelial cells and endothelial cells. The main function of arginase here, is to regulate the formation of nitric oxide, indirectly competing for the common substrate L- arginine. The NO forms peroxynitrite on reaction with reactive oxygen species due to oxidative stress. Peoxynitrite is unstable molecule and breaks down to nitrite and nitrate. The present research work was approved by Institutional Ethical committee. Informed consent was obtained from the patients and controls prior to the study. It is a case control study and it included 45 COPD patients between the age group of 40-60 years who attended the outpatient department of pulmonary medicine, Maharajah’s Institute of Medical Sciences, Nellimarla, Vizianagaram. These are labeled cases. 45 normal healthy age and sex matched individuals with normal FEV1/FVC ratio are considered as controls.