ENDOTHELIN-1 INDUCED PULMONARY-EDEMA IS NOT CAUSED BY ENHANCED CAPILLARY-PERMEABILITY IN BLOOD-FREE PERFUSED RABBIT LUNGS

Endothelin-1 has been shown to induce pulmonary vasoconstriction and e dema formation in the lung. To examine the pathomechanisms of ET-1 ind uced edema formation, the capillary filtration coefficient (C-fc) was determined after endothelin application in the isolated perfused rabbi t lung. The gravimetric measurement of C-fc has been shown to be a val uable indicator of capillary permeability. ET-1 induced an increase in pulmonary arterial pressure during the observation period of 120 minu tes (p<0.05) and an onset of edema formation 60 minutes after endothel in challenge (p<0.05 at 120 minutes). C-fc was determined before (0 mi n) and 30, 60, 90 and 120 minutes after ET-1 injection. No significant changes in C-fc were detectable at any time, thus indicating that ET- 1 induced edema is not caused by enhanced capillary permeability in pu lmonary microvasculature.