Phospholipase A2 (PLA2) activity in rabbit chondrocytes

The effects of recombinant interleukin-1β (rIL-1β), recombinant tumor necrosis factor (rTNFα) 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×above controls in the presence of 8×10−12M (5 U) rIL-1β or 5×10−9M rTNFα after 20 hr incubation. PLA2 activity remained constant with 1–50 ng/ml of either growth factor. PGE2 release significantly increased (p<0.05) when the chondrocytes were incubated with rIL-1β, bFGF and EGF alone, but not with rTNFα above. These data suggest PLA2 activity and PGE2 release are not coordinately regulated in rabbit chondrocytes.