Increased pulmonary vascular permeability as a cause of re-expansion edema in rabbits.
In order to study the mechanism(s) underlying re-expansion edema, we measured the concentration of labeled albumin (RISA) in the extravascular, extracellular water (EVECW) of the lung as a measure of pulmonary vascular permeability. Re-expansion edema was first induced by rapid re-expansion of rabbit lungs that had been collapsed for 1 wk by pneumothorax. The RISA in EVECW was expressed as a fraction of its plasma concentration: (RISA)L/(RISA)PL. The volume of EVECW (ml/gm dry lung) was measured using a 24Na indicator. Results in re-expansion edema were compared with normal control lungs and with oleic acid edema as a model of permeability edema. In re-expanded lungs, EVECW (3.41 +/- SD 1.24 ml/g) and (RISA)L/(RISA)PL 0.84 +/- SD 0.15) were significantly increased when compared with normal control lungs (2.25 +/- 0.41 ml/g and 0.51 +/- 0.20, respectively). Results in oleic acid edema (5.66 +/- 2.23 ml/g and 0.84 +/- 0.23) were similar to re-expansion edema. This suggested that re-expansion edema is due to increased pulmonary vascular permeability caused by mechanical stresses applied to the lung during re-expansion.
D000818:Animals; D001834:Body Water / Q000032:analysis; D002199:Capillary Permeability; D005110:Extracellular Space / Q000032:analysis; D005260:Female; D008168:Lung / Q000098:blood supply*; D008297:Male; D019301:Oleic Acid; D009829:Oleic Acids; D011031:Pneumothorax, Artificial; D011651:Pulmonary Artery / Q000503:physiopathology; D011654:Pulmonary Edema / Q000209:etiology* / Q000503:physiopathology; D011667:Pulmonary Veins / Q000503:physiopathology; D011817:Rabbits; D012711:Serum Albumin, Radio-Iodinated; D013314:Stress, Mechanical
D009829:Oleic Acids; D012711:Serum Albumin, Radio-Iodinated; D019301:Oleic Acid