in the present study , we have investigated the effects of graded doses of inhaled whole cigarette smoke on this function by measuring the rate of movement of horseradish peroxidase ( hrp ) from the airways lumen across the tracheal epithelium into blood , by assessing the penetration of hrp into tracheal epithelium using transmission electron microscopy , and by examining the morphology of tracheal epithelial tight junctions using the freeze-fracture technique .
C1179002
tracheal
C0040578
tracheal