Effects of the phospholipase C inhibitor, U73122 (A, 10 μM) and pertussis toxin (PTX, 100 ng/ml) (B) and a calcium chelator, BAPTA-AM (10 μM) on antigen-mediated Hex release. Results are expressed as mean ± SE and are from three independent experiments performed in duplicate. The basal value of percentage Hex release was about 5%. U73122 and BAPTA-AM inhibited both antigen-induced and ADP-enhanced Hex release, whereas PTX only blocked ADP-enhanced Hex release.