S. Rounds et al., EFFECT OF HYPERCARBIA ON SURFACE-PROTEINS OF CULTURED BOVINE ENDOTHELIAL-CELLS, American journal of physiology. Lung cellular and molecular physiology, 17(6), 1997, pp. 1141-1146
Hypercarbia is a common complication of respiratory failure, and the t
echnique of ''permissive hypercapnia'' is used to ventilate individual
s with increased peak airway pressures on mechanical ventilators, resu
lting in elevated arterial PCO2. We studied the effects of hypercarbia
on cultured bovine aortic and main pulmonary artery endothelial cell
surface proteins, assessing cell surface iodination using lactoperoxid
ase bound to latex microspheres. We found that 4 h of exposure to 10%
CO2 increased the display of substances of apparent molecular masses o
f 27, 47, and 52 kDa. This effect was not mimicked by acidotic media.
Western blots of detergent extracts of main pulmonary artery endotheli
al cell monolayers did not show increased expression of carbonic anhyd
rase TV (molecular mass = 52 kDa) after incubation under hypercarbic c
onditions. Hypercarbia did not change the pattern of [S-35]methionine
incorporation into endothelial cell proteins. We conclude that hyperca
rbia of 4-h duration changes iodinated endothelial cell surface protei
ns. We speculate that this effect may be related to changes in secreti
on or display of apical cell membrane-associated proteins.