IVM does not affect surface expression of P2X4Rs. A, a representative blot showing that there is no change in the surface expression (biotinylated fraction) of P2X4Rs after treatment with IVM. Control (Cont), 1 μM ATP; IVM 20 sec, 3 μM IVM + 1 μM ATP; IVM 2 min, oocytes treated with 3 μM IVM for 2 min before the addition of 1 μM ATP. B, analysis of the data from five separate experiments. Data are presented as ratio of biotinylated and total fractions after densitometry analysis of the protein bands.