Cigarette Smoke–induced Oxidative Stress: A Role in Chronic Obstructive Pulmonary Disease Skeletal Muscle Dysfunction

Abstract

Rationale Inflammation and oxidative stress contribute to muscle dysfunction in patients with chronic obstructive pulmonary disease (COPD). Oxidants contained in cigarette smoke (CS) induce adverse effects on tissues through oxidative phenomena. Objectives To explore oxidative stress and inflammation in quadriceps of human smokers and in diaphragm and limb muscles of guinea pigs chronically exposed to CS. Methods Muscle function, protein oxidation and nitration, antioxidants, oxidized proteins, inflammation, creatine kinase activity, and lung and muscle structures were investigated in vastus lateralis of smokers, patients with COPD, and healthy control subjects and in diaphragm and gastrocnemius of CS-exposed guinea pigs at 3, 4, and 6 months. Measurements and main results Compared with control subjects, quadriceps muscle force was mildly but significantly reduced in smokers; protein oxidation levels were increased in quadriceps of smokers and patients with COPD, and in respiratory and limb muscles of CS-exposed animals; glycolytic enzymes, creatine kinase, carbonic anydrase-3, and contractile proteins were significantly more carbonylated in quadriceps of smokers and patients with COPD, and in respiratory and limb muscles of CS-exposed guinea pigs. Chronic CS exposure induced no significant rise in muscle inflammation in either smokers or rodents. Muscle creatine kinase activity was reduced only in patients with COPD and in both diaphragm and gastrocnemius of CS-exposed anima…