P. Dieter et al., BAPTA INDUCES A DECREASE OF INTRACELLULAR FREE CALCIUM AND A TRANSLOCATION AND INACTIVATION OF PROTEIN-KINASE-C IN MACROPHAGES, Biological chemistry Hoppe-Seyler, 374(3), 1993, pp. 171-174
Addition of BAPTA/AM to liver macrophages lowered the level of [Ca2+]i
and induced a translocation and inactivation of protein kinase C. The
phorbol ester- and zymosan-induced release of arachidonic acid, prost
aglandin E2 and superoxide, the formation of inositol phosphates upon
addition of zymosan and the lipopolysaccharide-induced synthesis of TN
F-alpha was inhibited by pretreatment of the cells with BAPTA/AM. Simu
ltaneous addition of A 23187 to elevate [Ca]i could not reverse the in
hibitory effect of BAPTA. Phagocytosis of zymosan and formation of pro
staglandin E2 from exogenously added arachidonic acid or upon addition
of A 23187 was not altered by BAPTA/AM. No protein kinase C activity
could be measured in homogenates obtained from BAPTA/AM-pretreated cel
ls. These results indicate that the action of BAPTA in eucaryotic cell
s is not limited to its chelating effect on calcium but that BAPTA lea
ds to a translocation and inactivation of protein kinase C.