title: Histamine release from Weibel-Palade bodies of toad aortas induced by endothelin-1 and sarafotoxin-S6b.
abstract: BACKGROUND
  Endothelin-1 (ET-1) and sarafotoxin-S6b (STX) induce a remarkable degranulation of Weibel-Palade (WP) bodies prior to the vasocontraction of toad aortas. As WP bodies play the role of a reservoir site of the histamine in the endothelial cells, there is the possibility that ET-1 and STX evoke the release of histamine from WP bodies of this vessel.
  
  
  METHODS
  Histamine concentrations were assayed by high-performance liquid chromatography (HPLC) from the perfusate after being perfused with a solution containing ET-1 and STX. Each vessel was fixed and embedded for conventional electron microscopy and immunoelectron microscopy using antihistamine sera.
  
  
  RESULTS
  The appreciable concentrations of histamine were assayed by HPLC from the perfusate after the toad aortas were perfused with a solution containing ET-1 and STX. The immunoelectron microscopy revealed that histamine immunoreactive gold particles in the WP bodies remarkably decreased in number in the treated samples when compared to the control ones. Our immunoelectron micrographs indicated that the release of histamine from the endothelial cells occurred in association with the degranulation and the exocytosis of the WP bodies after treatment with ET-1 and STX.
  
  
  CONCLUSIONS
  The present study clearly shows that ET-1 and STX induce the histamine release from WP bodies of the toad aortas by means of HPLC and immunoelectron microscopy. Histamine discharged from the WP bodies may be involved in the vasocontraction evoked by ET-1 and STX.
authors.affiliation: Department of Anatomy, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Doi
authors.forename: T
authors.initials: T
authors.lastname: Ozaka
authors.forename: M
authors.initials: M
authors.lastname: Katsuki
authors.forename: H
authors.initials: H
authors.lastname: Fukushige
authors.forename: E
authors.initials: E
authors.lastname: Toyama
authors.forename: Y
authors.initials: Y
authors.lastname: Kanazawa
authors.forename: K
authors.initials: K
authors.lastname: Arashidani
authors.forename: S
authors.initials: S
authors.lastname: Fujimoto
mesh_terms: D000818:Animals; D001012:Aorta, Abdominal / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D002023:Bufo bufo; D015550:Cell Degranulation; D002851:Chromatography, High Pressure Liquid; D003594:Cytoplasmic Granules / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D016232:Endothelins / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure*; D006636:Histamine Release / Q000187:drug effects*; D007150:Immunohistochemistry; D016253:Microscopy, Immunoelectron; D014757:Viper Venoms / Q000494:pharmacology*
chemical_list: D016232:Endothelins; D014757:Viper Venoms; C057354:sarafotoxins s6