抄録
Rat mast cell granules were obtained by homogenation of highly purified rat mast cells and isolated in a Percoll gradient. PI kinase in rat mast cell granules were assayed by measuring the incorporation of 32P from [γ32P] ATP into diphosphoinositide (DPI) in the absence of exogenous PI. Lipids were isolated with methanol chloroform/HCl and were separated by thin-layer chromatography on oxalic acid impregnated silica gel plates. DPI areas were identified by staining with iodine, scraped and measured for 32P radioactivity. The enzyme was inhibited by 50-500μM adenosine, 5-500μM ADP and AMP. Among several anti-allergic drugs investigated, 10-1000μM theophylline and 1-100μM azelastine inhibited the enzyme, but 1-100μM disodium cromoglycate and ketotifen had little effect.
