Figure 3.

(a) Known phospholipase 2 (PLA₂) inhibitors, bromoenol lactone (BEL, calcium-independent PLA₂), arachidonoyltrifluoromethyl ketone (ATFMK, cytosolic PLA₂) and p-bromophenacyl bromide (BPB, secretatory PLA₂), have no effect on the c48/80-induced [³⁵S]GTPγS binding to 4-week-old rat brain white matter areas. [³⁵S]GTPγS autoradiography was conducted in three steps with DPCPX (1 μM) present throughout steps 2 and 3, as detailed in the Methods section. (b) Quantitative autoradiography data on the corpus callosum, selected to represent the white matter. The autoradiography images were digitized and bound radioactivity values were obtained from the digitized images for statistical analysis. Values are mean+s.e.m. representing four sections from four developing (4-week-old) animals. Scale bar=5 mm. c48/80 (100 μg ml⁻¹; MP Biomedicals) was included in the labeling step of autoradiography along with the inhibitors (each at 50 μM) as indicated in the figure. No significant alterations were detected in c48/80-induced [³⁵S]GTPγS binding when inhibitors were included. Risk level: P<0.05 compared to the respective control treatment in the corpus callosum.