抄録
Rat peritoneal mast cells purified on a Percoll gradient were challenged with different concentrations of substance P (SP), and the effect of 8-methoxypsoralen (8-MOP) plus long-wave ultraviolet light (UVA) irradiation (PUVA) on SP-induced histamine release from the cells was investigated. SP at a concentration of 10-5 mol/l caused a significant histamine release with a significant increase in intracellular calcium concentrations ( [Ca2+] i) . 8-MOP or UVA irradiation alone at doses used in the present study induced no histamine release from the cells, and showed no significant effects on the SP-induced histamine release from the cells. On the other hand, PUVA inhibited the SP-induced histamine release in a dose-dependent manner of UVA at doses from 0.5 to 3.0 J/cm2 in parallel with the reduction of [Ca2+] i. These data suggest that PUVA inhibits histamine release from SP-activated rat peritoneal mast cells through the suppression of [Ca2+] i.
