Brain histamine turnover enhanced by footshock

When footshock was given to mice at 15-s intervals for 30–120 min, there was a significant increase in the brain level of the tele-methyl-histamine (t-MH), a predominant metabolite of brain histamine (HA). This footshock-induced elevation of the t-MH level also occurred in mice pretreated with pargyline but not in mice pretreated with metoprine. The footshock facilitated the HA depletion induced by α-fluoromethylhistidine. These results suggest that footshock increases the brain HA turnover.