Prostaglandins and cannabis--VIII. Elevation of phospholipase A2 activity by cannabinoids in whole cells and subcellular preparations.

The previously reported release of arachidonic acid by THC has now been demonstrated in murine Leydig cells and WI-38 human lung fibroblasts showing the generality of the effect. The release reaction could be antagonized by phospholipase A2 inhibitors such as quinacrine and quinine, suggesting that THC can stimulate the activity of this enzyme. Further evidence for this possibility was obtained by demonstrating the release effect on a subcellular fraction which contained the phospholipase A2 activity. The stimulation of this enzyme could have profound effects on prostaglandin synthesis and/or on the integrity of various membrane structures.