title: Comparison of cellular mechanisms underlying histamine release from rat mast cells induced by ionic and nonionic radiographic contrast media.
abstract: OBJECTIVE
  To determine the cellular mechanisms underlying mast cell histamine release induced by ionic and nonionic radiographic contrast media.
  
  
  METHODS
  Histamine release from rat pulmonary mast cells was measured after incubation with various radiographic contrast media. The cellular cAMP content was determined by an enzymatic immunoassay.
  
  
  RESULTS
  Both ionic and nonionic contrast media stimulated the histamine release, although the former was more potent than the latter. Dibutyryl cAMP suppressed histamine release evoked by ionic but not nonionic contrast media in a manner dependent on A kinase. The cellular cAMP content was lowered only by ionic contrast media. However, a secretory phospholipase A2 inhibitor p-bromophenacyl bromide inhibited both ionic and nonionic contrast media-evoked histamine releases.
  
  
  CONCLUSIONS
  We demonstrated for the first time the difference and similarity in the cellular mechanisms underlying histamine release induced by ionic and nonionic contrast media, in which the reduction in cAMP was specific for ionic materials and the activation of secretory phospholipase A2 may be common to both agents.
authors.affiliation: Department of Hospital Pharmacy, Faculty of Medicine, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Japan. yositou@st.hosp.kyushu-u.ac.jp
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Itoh
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Sendo
authors.forename: Takahisa
authors.initials: T
authors.lastname: Yano
authors.forename: Mami
authors.initials: M
authors.lastname: Saito
authors.forename: Toshio
authors.initials: T
authors.lastname: Kubota
authors.forename: Ryozo
authors.initials: R
authors.lastname: Oishi
mesh_terms: D000098:Acetophenones / Q000494:pharmacology; D000818:Animals; D001095:Arachidonic Acids / Q000494:pharmacology; D003994:Bucladesine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D003287:Contrast Media / Q000494:pharmacology*; D000242:Cyclic AMP / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006636:Histamine Release / Q000187:drug effects*; D066298:In Vitro Techniques; D008168:Lung / Q000166:cytology; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000378:metabolism*; D010741:Phospholipases A / Q000037:antagonists & inhibitors; D054467:Phospholipases A2; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D000098:Acetophenones; D001095:Arachidonic Acids; D003287:Contrast Media; D004791:Enzyme Inhibitors; C081565:arachidonyltrifluoromethane; D003994:Bucladesine; D000242:Cyclic AMP; D010741:Phospholipases A; D054467:Phospholipases A2; C006821:4-bromophenacyl bromide; D002118:Calcium