PH AND TEMPERATURE MODULATE NOREPINEPHRINE-DEPENDENT CHANGES IN ENDOTHELIAL PERMEABILITY

To evaluate the role of pH and temperature in norepinephrine (NE)-medi ated decreases in endothelial permeability, we studied bovine pulmonar y arterial endothelial monolayers at pH values of 4-9 and at temperatu res of 35-39 degrees C. Only extremes of pH-modulated endothelial perm eability and temperature had no effect. Although both NE and 3-isobuty l-1-methylxanthine decreased endothelial permeability, their effects w ere diminished by low pH and high temperature. Fever and acidosis may contribute to the edema seen in septic shock by a novel mechanism: att enuation of the barrier-improving function of NE.