Cell Surface ATP Synthase: A Potential Target for Anti-Angiogenic Therapy - Extracellular ATP and Adenosine as Regulators of Endothelial Cell Function - page 145

Fig. 9.6 Inhibition of ATP synthase activity and intracellular pH regulation by MAb3D5AB1.
( a ) Extracellular ATP generation by HUVEC was measured at pH e 6.7 ( ) and pH e 7.2 ( ).
MAb3D5AB1 inhibited cell surface ATP synthesis in a dose-dependent manner at low pH e but
not at pH e 7.2. ( b ) The intracellular pH of HUVEC was monitored by fluorescence of the pH-
sensitive fluoroprobe carboxy snarf-1 acetoxymethyl ester after acute extracellular acidification
from pH e 7.4 to 6.7. Intracellular acidification occurred to a greater degree in the presence of
10 μ g/ml MAb3D5AB1 ( × ) than in media alone ( ). (Figure 4 reprinted with permission from

Chietal.[15])

9.3 ATP Synthase and Endothelial Cell Response to Shear Stress

The luminal surface of endothelial cells is exposed to shear stress imposed by
blood flow through the vasculature. Transduction of this mechanical force induces a
variety of responses in endothelial cells that are involved in vasoregulation and vas-
cular remodeling. Extracellular ATP production by ATP synthase has recently been