Abstract: Abstract:【OBJECTIVE】to study the main types and activity of phosphodiesterase (PDE) existed in porcine neutrophils through the examination of PDE gene expression, activity and selective inhibitor experiments for the investigation of relation between PDE distribution, activity change, adjustment on cAMP and cGMP content and neutrophil function;【METHOD】PDE gene expression was detected by RT-PCR, and PDE activity was calculated by cylic nucleotides content change examined with HPLC before and after the PDE reaction;【RESULTS】mRNAs of PDE1B, 2A, 3A, 3B, 4A, 4B, 4C, 4D, 5A, 7A, 7B, 8A, 8B, 9A, 11A were expressed in porcine neutrophils, and selective inhibitor experiments indicated PDE4 and PDE5 were respectively the main types to hydrolyze cAMP and cGMP; cAMP/cGMP-PDE in the extent of 10 µL ~ 40 µL had a good linear correlation with its activity (r＝0.9929, 0.9992);【CONCLUSION】there are at least 15 PDE types existed in porcine neutrophils, in which PDE4 and PDE5 are the two main types; PDE volume has a good linear correlation with its activity, to some extent, which supply the base for the choose herbal regulators of neutrophil function of PDE type.

Key words: Neutrophil, Phophodiesterase, Swine, HPLC, Rolipram, Sildenafil