The uptake of ethidium bromide by acini incubated at 37°C in the presence of 1 mM ATP increased

with time and reached after 5 min about 10% of maximal uptake measured in the presence of

digitonin … The response to ATP was dose-dependent (half-maximal concentration around

40 μM) and it was decreased when the temperature was lowered to 25°C … Benzoyl-ATP reproduced

the response to ATP (half-maximal concentration around 10 μM). UTP or 2-methylthioATP had

no effect … The permeabilization in response to ATP was blocked by oxidized ATP and by magnesium

and inhibited by Coomassie blue … ATP increased the activity of a calcium-insensitive phospholipase

A 2 (iPLA 2 ) … Bromoenol lactone (BEL) inhibited the iPLA 2 stimulated by ATP but potentiated

the uptake of ethidium bromide in response to the purinergic agonist … From these results it

is concluded that the activation of P2X 7 receptors permeabilizes rat submandibular …