Antagonistic effects of psycholeptic drugs on stress-induced analgesia.
Stress-induced analgesia was significantly antagonized by naloxone and was dose-dependently reduced by diazepam, chlordiazepoxide, flurazepam, medazepam, nitrazepam, estazolam, phenobarbital, chlorpromazine, levomepromazine, haloperidol and propranolol. In contrast to psycholeptics, morphine substantially increased in threshold of nociceptive response in the post-stress session. Centrally acting muscle relaxants, tolperisone and carosiprodol had no substantial anti-stress effects. These results suggest that the stress-induced analgesia is probably mediated through endogenous opioids in the central nervous system. The approach used in our study provides a simple method for assessing the anti-stress action of psycholeptics.
D000698:Analgesia; D000818:Animals; D014151:Anti-Anxiety Agents / Q000494:pharmacology; D014150:Antipsychotic Agents / Q000494:pharmacology; D001569:Benzodiazepines; D003864:Depression, Chemical; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009125:Muscle Relaxants, Central / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D009619:Nociceptors / Q000187:drug effects; D011619:Psychotropic Drugs / Q000494:pharmacology*; D013312:Stress, Physiological / Q000503:physiopathology*
D014151:Anti-Anxiety Agents; D014150:Antipsychotic Agents; D009125:Muscle Relaxants, Central; D011619:Psychotropic Drugs; D001569:Benzodiazepines; D009270:Naloxone