title: Rat paw oedema and mast cell degranulation caused by two phospholipase A2 enzymes isolated from Trimeresurus mucrosquamatus venom.
abstract: Two phospholipase A2 (PLA2) enzymes, TMVPLA2 I and TMVPLA2 II, isolated from Trimeresurus mucrosquamatus venom (TMV) induce rat hind-paw oedema in a dose-dependent manner. This response is suppressed by pretreatment with diphenhydramine, methysergide or compound 48/80, which reduces tissue histamine content. In isolated mast cells, TMVPLA2 I and TMVPLA2 II cause concentration-, time- and calcium-dependent release of histamine and beta-glucuronidase. This effect is inhibited by disodium cromoglycate, mepacrine, nordihydroguaiaretic acid, piriprost and BW 755C, but not by aspirin or indomethacin. These observations indicate that the mast cell plays a predominant role in TMVPLA2 I- and TMVPLA2 II-induced paw oedema, and that venom PLA2 enzyme needs an intact lipoxygenase pathway to induce mast cell degranulation.
authors.affiliation: Department of Medical Research, Taichung Veterans General Hospital, Taipei, Taiwan.
authors.forename: J P
authors.initials: JP
authors.lastname: Wang
authors.forename: C M
authors.initials: CM
authors.lastname: Teng
mesh_terms: D000818:Animals; D015550:Cell Degranulation; D003435:Crotalid Venoms / Q000633:toxicity*; D004155:Diphenhydramine / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D004487:Edema / Q000209:etiology* / Q000378:metabolism / Q000517:prevention & control; D006636:Histamine Release / Q000187:drug effects; D008407:Mast Cells / Q000187:drug effects*; D008784:Methysergide / Q000627:therapeutic use; D010740:Phospholipases / Q000633:toxicity*; D010741:Phospholipases A / Q000037:antagonists & inhibitors / Q000633:toxicity*; D054467:Phospholipases A2; D051381:Rats; D011919:Rats, Inbred Strains; D012910:Snake Venoms / Q000633:toxicity*; D003189:p-Methoxy-N-methylphenethylamine / Q000627:therapeutic use
chemical_list: D003435:Crotalid Venoms; D012910:Snake Venoms; D003189:p-Methoxy-N-methylphenethylamine; D004155:Diphenhydramine; D010740:Phospholipases; C069559:TMVPLA2 I; C069562:TMVPLA2 II; D010741:Phospholipases A; D054467:Phospholipases A2; D008784:Methysergide