Effect of haloperidol [HAL] on leucopyrokinin [LPK]-induced biphasic hyper- and hypothermic effect in rats

The aim of present study was to evaluate mechanisms involved in thermomodulatory effect LPK in rats.Experiments were performed on adult Wistar male rats. LPK was applied either intracerebroventricularly (icv), or intraperitoneally (ip) using the similar program and technique of experiments as in our previous study. We confirmed in this paper the results of our previous reports that icv administration LPK at the dose of 20 nmol induced evident significant rectal hypothermia, while lower dose LPK of 1 nmol icv exerted significant hyperthermic effect. Peripherally applied LPK at the range of doses 10-100 nmol/100 g ip displayed slight bimodal (hyperthermic and hypothermic) effect on rectal temperature. Prior administration of haloperidol, an antagonist of central dopamine receptors blocked both effects LPK applied either icv or ip. Obtained results indicate that both hypothermic and hyperthermic effects LPK are also modulated by central dopaminergic receptors.