title: Inhibition of substance-P-induced histamine release from rat peritoneal mast cells by 8-methoxypsoralen plus long-wave ultraviolet light irradiation: decreased intracellular calcium as a possible mechanism.
abstract: Rat peritoneal mast cells purified on a Percoll gradient were activated by substance P (SP) and the effect of 8-methoxypsoralen (8-MOP) plus long-wave ultraviolet light (UVA) irradiation (8-MOP/UVA) on SP-induced histamine release from the cells was investigated. At a concentration of 10(-5) M SP caused a significant histamine release. 8-MOP or UVA irradiation alone at the doses used in the present study neither induced a histamine release nor had any significant effects on SP-induced histamine release from mast cells. On the other hand, 8-MOP/UVA inhibited SP-induced histamine release; this inhibition was dependent on the UVA doses (0.5-3.0 J/cm2) and was accompanied by a reduction in the rise in intracellular calcium concentrations ([Ca2+]i). These data suggest that 8-MOP/UVA inhibits histamine release from SP-activated rat peritoneal mast cells by suppressing the rise in [Ca2+]i.
authors.affiliation: Department of Dermatology, Gunma University School of Medicine, Maebashi, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Amano
authors.forename: M
authors.initials: M
authors.lastname: Kurosawa
authors.forename: Y
authors.initials: Y
authors.lastname: Miyachi
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D006636:Histamine Release / Q000187:drug effects* / Q000528:radiation effects*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D008407:Mast Cells / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D008730:Methoxsalen / Q000494:pharmacology*; D010529:Peritoneal Cavity / Q000166:cytology; D017319:Photosensitizing Agents / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013373:Substance P / Q000494:pharmacology*; D014466:Ultraviolet Rays
chemical_list: D017319:Photosensitizing Agents; D013373:Substance P; D007770:L-Lactate Dehydrogenase; D002118:Calcium; D008730:Methoxsalen