Increased sheep lung vascular permeability caused by histamine. Circ Res 37

sponses of lung lymph flow and lymph and plasma pro-tein concentrations to steady state elevations of pul-monary vascular pressures made by inflating a left atrial balloon with those after an intravenous infusion of 10W-10 ° Pseudomonas aeruginosa. Lymph flow in-creased when pressure was increased, but lymph-plasma protein concentration ratios always fell and lymph pro-tein flow (lymph flow X lymph protein concentration) increased only slightly. After Pseudomonas, sheep had transient chills, fever, leukopenia, hypoxemia, increased pulmonary artery presssure and lymph flow and de-creased left atrial pressure and lymph protein concen-tration. 3-5 h after Pseudomonas, when vascular pres-sures and lymph protein concentrations had returned to near base line, lymph flow increased further to 3-10 times base line and remained at a steady level for many hours. During this steady state period, lymph-plasma protein concentration ratios were similar to base line and lymph protein flow was higher than in the increased pressure studies. Two sheep died of pulmonary edema 7 and 9 h after Pseudomonas, but in 16 studies, five other sheep appeared well during the period of highest lymph flow and all variables returned to base line in 24-72 h. Six serial indicator dilution lung water studies in five sheep changed insignificantly from base line after Pseudomonas. Postmortem lung water was high in the two sheep dead of pulmonary edema and one other, but A preliminary report of some of the data in this paper has been published (Chest. 65: 51 (Suppl.). 1974)