Anti-muricide mechanisms of chlorpromazine and imipramine in OB rats: adrenoceptors and hypothalamic functions.
Chlorpromazine (CPZ) microinjected into the posterior part of the lateral hypothalamus (p-LH) and the lateral preoptic area (1-POA) of OB rats shows anti-muricide and cataleptogenic effects as well as a drowsy pattern in cortical EEG, while imipramine (IMP) injected into p-LH shows anti-muricide and cataleptogenic effects without change of cortical EEG. The present study examined the effects of drugs injected into p-LH and 1-POA on muricide, catalepsy and cortical and limbic EEG. CPZ (20, 50 micrograms) suppressed muricide and induced catalepsy and an EEG drowsy pattern in the two regions. The effects of CPZ in p-LH were similar to those of propranolol (PRO). In 1-POA, the anti-muricide effect of CPZ was similar to that of phenoxybenzamine, whereas the cataleptogenic and EEG effects were similar to those of PRO. IMP (10, 20 micrograms) in p-LH showed anti-muricide and cataleptogenic effects and induced a slight drowsy pattern in limbic EEG. The effects were similar to those of atropine. Lidocaine did not show any effects in the two regions. The cataleptogenic effects of CPZ and IMP did not appear related with the anti-muricide effects. The results suggest that the anti-muricide effect of CPZ in the hypothalamus depends on its adrenoceptor blockage, while that of IMP relates to its anticholinergic effect. In addition, beta-receptors in the hypothalamus appear related to the arousal system and dopaminergic functions.
D000374:Aggression / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D002375:Catalepsy / Q000139:chemically induced; D002746:Chlorpromazine / Q000494:pharmacology*; D004569:Electroencephalography; D006801:Humans; D007031:Hypothalamus / Q000502:physiology*; D007099:Imipramine / Q000494:pharmacology*; D008297:Male; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011941:Receptors, Adrenergic / Q000187:drug effects*
D011941:Receptors, Adrenergic; D011433:Propranolol; D007099:Imipramine; D002746:Chlorpromazine