... recombinantTNFa was supplied by R & D Systems (Abingdon, Oxon,UK). Wortmannin, brefeldin A and propranolol wereobtained from Calbiochem (Nottingham, UK). Fetalbovine serum,L-glutamine and ... first5 min of stimulation.Effect of PI3-kinase and ARF inhibitors on OÀ2 and PLD activationSelective pharmacological inhibitors were used to assessthe role of PI3-kinase and ARF proteins on ... such as ARF1 and ARF3. Morerecently, ARF6 has been implicated in activating PLD and functional responses in chromaffin cells [33], macrophages[34] and epithelial cell lines [35], and in neutrophil-like...