The subcellular distribution of PKC(alpha) and
PKC(gamma) was studied in homogenates of cerebral cortex from rats subjected to 10 and 15 min of
ischemia and 15 min of
ischemia followed by 1 h, 6 h, 24 h, 48 h, and 7 days of reperfusion. During
ischemia no significant changes in the levels of PKC (alpha) were seen. During the first hour of reperfusion, a transient 2.5-fold (P less than 0.05) increase in PKC (alpha) levels was observed in the particulate fraction. In contrast, a three-fold increase of
PKC(gamma) in the particulate fraction concomitant with a 40% decrease in the cytosol was noted during
ischemia. In the postischemic phase the levels in the cytosol decreased to 35% of control values at 2 days following
ischemia, with a concomitant decrease in the particulate fraction to control levels. The redistribution of PKC to the cell membranes during and following
ischemia could be due to
ischemia induced receptor activation, increased levels of
diacylglycerols, arachidonate and intracellular
calcium, and may be of importance for the development of ischemic neuronal damage.