title: Effects of phenazepam on the behavior of C57BL/6 and BALB/c mice in the open field test after naloxone pretreatment.
abstract: We studied the effects of phenazepam (0.075 mg/kg) after pretreatment (5 minutes before) with naloxone (10 mg/kg) on open-field behavior of C57Bl/6 and BALB/c mice. In ex vivo experiments, we studied the effects of naloxone (1 and 10 mg/kg) on receptor binding of [(3)H]-flunitrazepam by membranes of brain fraction (P1+P2) of C57Bl/6 and BALB/c mice. It was shown that naloxone increased motor activity in the open field in BALB/c mice and decreased this parameter in C57Bl/6 mice. During combined treatment, naloxone potentiated the activating effects of phenazepam on the open-field behavior of BALB/c mice and slightly increased the sedative effect of this drug in C57Bl/6 mice. Naloxone stimulated reception of [(3)H]-flunitrazepam in BALB/c mice and slightly increased radioligand binding in C57Bl/6 mice. These data attest to enhanced reception in benzodiazepine site of GABAA-receptor under conditions of opioid receptor blockade, the presence of anxiolytic or sedative (depending on the phenotype of the response to emotional stress) effect of naloxone, and co-directed effects of naloxone and benzodiazepine tranquilizer on open-field behavior of C57Bl/6 and BALB/c mice.
authors.affiliation: V. V. Zakusov Institute of Pharmacology, Russian Academy of Medical Sciences, Moscow, Russia. av-nadorova@mail.ru.
authors.forename: S B
authors.initials: SB
authors.lastname: Seredenin
authors.forename: A V
authors.initials: AV
authors.lastname: Nadorova
authors.forename: L G
authors.initials: LG
authors.lastname: Kolik
authors.forename: M A
authors.initials: MA
authors.lastname: Yarkova
mesh_terms: D000818:Animals; D001569:Benzodiazepines / Q000494:pharmacology*; D005106:Exploratory Behavior / Q000187:drug effects*; D005445:Flunitrazepam / Q000378:metabolism; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology; D011869:Radioligand Assay; D013045:Species Specificity; D018709:Statistics, Nonparametric; D013315:Stress, Psychological / Q000188:drug therapy*
chemical_list: D001569:Benzodiazepines; D009270:Naloxone; C017928:phenazepam; D005445:Flunitrazepam