Phospholipase A2 (PLA2) activity in rabbit chondrocytes.

The effects of recombinant interleukin-1 beta (rIL-1 beta), recombinant tumor necrosis factor (rTNF alpha) and two growth factors, basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) on PLA2 activity and prostaglandin E2 (PGE2) release were investigated using rabbit chondrocytes. Cellular PLA2 activity increased 2-10 x above controls in the presence of 8 x 10(-12) M (5 U) rIL-1 beta or 5 x 10(-9) M rTNF alpha after 20 hr incubation. PLA2 activity remained constant with 1-50 ng/ml of either growth factor. PGE2 release significantly increased (p less than 0.05) when the chondrocytes were incubated with rIL-1 beta, bFGF and EGF alone, but not with rTNF alpha above. These data suggest PLA2 activity and PGE2 release are not coordinately regulated in rabbit chondrocytes.