[Substance P and effects of ethanol on the central mechanisms of the escape reaction in rabbits].

Substance P (SP) effects on the central mechanisms of escape reaction, elicited by threshold electrical stimulation of the ventromedial hypothalamus were investigated in rabbits pretreated with ethanol (0.5 g/kg). SP (30 micrograms/kg) was demonstrated to normalize in 71.4% of cases the excitability of the ventromedial hypothalamus which was decreased by ethanol and restored in 83.3% of cases the facilitatory effects of the midbrain reticular formation in escape reactions. However, SP was ineffective in the restoration of the inhibitory effects of the dorsal hippocamp on the excitability of the ventromedial hypothalamus that was obvious in intact animals. Partial normalizing effect of SP on escape reaction in rabbits after previous ethanol administration can be accounted for by the fact that both undecapeptide and ethanol are similar in their realization of central effects such as an interaction with the same brain neurotransmitters, interference with neuronal enzyme processes and reactions with opiate receptors.