Substance P against ethanol-induced alterations in central mechanisms of feeding and escape in rabbits.

Rabbits were treated with 0.5 g/kg ethanol intravenously and alterations of limbic-midbrain interactions in both feeding and escape elicited by threshold electrical stimulation of the lateral (LH) and ventromedial hypothalamus (VMH) were observed. Decrease of the VMH excitability and abolishing of inhibitory effects of the dorsal hippocampus (HPC) and facilitatory influences of the midbrain reticular formation (MRF) on both motivational hypothalamic centres were found in animals after ethanol administration. Subsequent single injection of substance P (SP) (30 microgram-kg i.v.) just at the height of alcohol manifestations in central mechanisms of feeding and escape led to restoration of the VMH excitability and facilitatory MRF influences on this motivational centre. SP administration was also found to restore the inhibitory hippocampal and facilitatory MRF effects on the excitability of the LH feeding centre. Partial and selective SP restoration of ethanol-induced alterations in feeding and escape which are observed in the present study, as well as the data of some other researchers, led to the suggestion that peptides could be used as factors of enhancing tolerance to ethanol or curing deleterious acute alcohol-induced effects in motivated behaviours in animals.