Figure 7.

Simplified hypothetical model demonstrating the sites of action of anti-arthritic therapeutics used in this study. sPLA₂ IIa provides the substrate for the production of the inflammatory mediators; platelet-activating factor (PAF), prostaglandins and leukotrienes. Additionally, sPLA₂ IIa is a ligand for the M-type receptor: sPLA₂ IIa agonist activity causes mast cell degranulation and activation of neutrophils. Ibuprofen, leflunomide and infliximab all act on inflammatory mediators downstream of sPLA₂ IIa actions. Prednisolone globally alters inflammatory gene transcription. AA, arachidonic acid; cPLA₂, cytosolic phospholipase A_2; PAF, platelet activating factor; MAP kinase, mitogen activated protein kinase; M-type receptor, muscle type receptor; sPLA₂ IIa, secretory phospholipase A₂ group IIa; TNFα, tumour necrosis factor alpha.