TISSUE PROTEIN WASHOUT IN SHEEP LUNG LYMPH

Abstract

At high microvascular filtration rates, the lung lymph protein concentration (CL) may be higherthan the filtrate protein concentration due to protein washed into the lymph from the lung tissuespace. To test that hypothesis, we increased the microvascular filtration rate in 5 anesthetizedsheep and determined the relationship between CL and the plasma protein concentration (CP).Then we extrapolated the data to estimate CL at CP = 0. Because the filtrate proteinconcentration should be zero at CP = 0, we recorded the extrapolated CL as the concentration oftissue protein in the lymph (Ct). Our Ct estimate (0.92?0.38g/dl) was significantly greater thanzero (P<0.05). This result is important because tissue protein in lymph may cause errors wheninvestigators use lung lymph to study microvascular permeability. However, our technique toestimate Ct may allow investigators to correct for the tissue protein problem.