ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 49, Number 5
JKCSEZ 49(5)
October 20, 2005 

Phospholipase D (PLD) activity is known to be modulated through cellular signaling pathways including membrane perturbation. In this study, we examined effect of digitonin on the PLD activity in monkey kidney epithelial Vero76 cells. At 30 μg/mL dosage of digitonin, the PLD activity was induced approximately 9 folds within 30 min at 37^oC. Under the same condition the increased membrane permeability could be verified by fluorescence microscope. The digitonin-induced PLD activity was inhibited as much as 70% by EGTA and pretreatment with various protein kinase inhibitors such as PD98059 and Ro32-0432 significantly decreased the digitonin-induced PLD activity. The results of inhibitor studies suggest an involvement of protein kinase C. This finding was further verified by blocking digitonin effect by the pretreatment with PMA for 24 hours. Additionally we examined the viability of Vero76 cells under the digitonin influence and tested the digitonin effect on the Vero76 cells transiently transfected with PLD1 and PLD2 cDNAs.