INCREASED PLASMA-LEVELS OF ATRIAL-NATRIURETIC-FACTOR, RENIN-ACTIVITY,AND LEUKOTRIENE-C4 IN CHRONIC OBSTRUCTIVE PULMONARY-DISEASE

We studied atrial natriuretic factor (ANF), plasma renin activity (PRA ), and plasma levels of leukotrienes (LTs) B4 and C4 in 23 patients wi th COPD undergoing right cardiac catheterization for suspected pulmona ry hypertension. Hemodynamic measurements together with concomitant AN F levels (both in venous and pulmonary artery blood and right atrial a nd pulmonary artery plasma levels of LTC4 and LTB4, were determined at rest (TO), after 30 min of breathing oxygen (3 L/min) (TI), and after 30 min recovering and breathing air (T2). Patients with effective exa cerbation or definitive evidence of left ventricular disease, hyperten sion, arrhythmias, or vasodilator or diuretic therapy were excluded. I ncreased levels of ANF, both in peripheral venous blood (117 +/- 65 pg /ml) and the pulmonary artery (153 +/- 75 pg/ml), were found in patien ts with COPD, with or without pulmonary hypertension. Levels of LTC4 w ere also significantly increased (366 +/- 406 pg/ml) when compared wit h our control values. No correlations among ANF, LTC4 values, function al tests, and hemodynamic measurements were found. Brief increased lev els of oxygen did not modify ANF or LTC4 plasma levels, either in pati ents with or without pulmonary hypertension.