Comparison of effects of phencyclidine and methamphetamine on body temperature in mice: a possible role for histamine neurons in thermoregulation

We compared the effects of phencyclidine (PCP) and methamphetamine on body temperature and brain histamine turnover in mice. Methamphetamine at 5 and 10 mg/kg produced dose-related increases in rectal temperature, whereas PCP given in the same doses had no significant effect. In mice pretreated with α-fluoromethylhistidine, an inhibitor of histidine decarboxylase, PCP produced a marked hyperthermia. PCP markedly accelerated brain histamine turnover, as measured by the accumulation of telemethylhistamine, a predominant metabolite of brain histamine, following administration of pargyline. Methamphetamine had no significant effect on the histamine dynamics. These results suggest involvement of brain histaminergic neurons in the action of PCP but not methamphetamine, and the presence of a histaminergic thermoregulatory mechanism.