Metalloproteinase-9 in circulating monocytes in pulmonary hypertension.

The role of matrix metalloproteinases (MMPs) in pulmonary hypertension (PH) is complex as MMPs are involved in both the vascular and cardiac remodelling associated with PH. To gain insight into this problem, monocytes were isolated from pulmonary arterial blood in patients suffering from PH, related to chronic obstructive pulmonary disease (n = 6), chronic pulmonary thromboembolism (n = 3) or pulmonary arterial hypertension (n = 8). The severity of PH was associated with decreases in cardiac index (CI) and mixed venous blood oxygen saturation (SO(2)), and an increase in right atrial pressure ().

Interpretation of high wedge pressure on exercise in patients with chronic obstructive pulmonary disease.

In a retrospective review of patients subjected to right heart catheterization, case records from 109 consecutive patients with chronic obstructive pulmonary disease (COPD) and wedge pressure > or =15 mm Hg on exercise were analyzed. Patients were separated into group 1, resting wedge pressure (P macro w) <15 mm Hg and difference between P macro w and right atrial pressure (P macro ra) change on exercise <5 mm Hg (n = 54), group 2, same P macro w at rest but increase in macro on exercise > or =5 mm Hg, being higher than that of P macro ra (n = 34), and group 3, P macro w > or =15 mm Hg at rest (n = 21). The occurrence of left heart disease increased from group 1 to group 3 (19, 53 and 71%, respectively), and the slope of the P macro w/stroke index relationship was lowest in group 3.

Role of NO pathway, calcium and potassium channels in the peripheral pulmonary vascular tone in dogs.

Because hypoxic pulmonary vasoconstriction occurs mainly in the small pulmonary arteries, the authors investigated the effects of drugs acting on the nitric oxide (NO) pathway and the calcium and potassium channels in the peripheral pulmonary circulation, without interference with the overall pulmonary or systemic circulation. Mixed venous blood was infused in wedged areas to study the pressure/flow relationship and to compute peripheral pulmonary vascular resistance (PPVR). The authors studied the effects of Nomega-nitro-L-arginine methyl ester (L-NAME), an NO synthase inhibitor, sodium nitroprusside (SNP, an NO donor), the calcium channel blockers verapamil, nifedipine and nicardipine, and the potassium channel opener levcromakalim, during normoxia and acute mild normocapnic hypoxia.

Changes in peripheral pulmonary vascular resistance after ioxaglate infusion in anesthetized dogs.

The pulmonary vascular resistance in a peripheral portion of the pulmonary vascular bed can be determined with a catheter wedged in a peripheral branch of the pulmonary artery, from the pressure increase induced by infusion of mixed venous blood at known flow rates. The volume of the wedged vascular bed can be estimated during fluoroscopy, from the volume of a contrast agent infused until the corresponding pulmonary vein can be seen. The present work was undertaken to determine the possible influence of this maneuver on the peripheral pulmonary vascular resistance (PPVR).