title: Effect of pertussis toxin on morphine, diphenhydramine, baclofen, clomipramine and physostigmine antinociception.
abstract: The effect of pretreatment with pertussis toxin at the doses of 0.25 and 0.50 micrograms per mouse i.c.v. on the analgesic effect produced by morphine (7 mg kg-1 s.c.), baclofen (4 mg kg-1 s.c.), diphenhydramine (20 mg kg-1 s.c.), clomipramine (25 mg kg-1 s.c.) and physostigmine (0.1-0.2 mg kg-1 s.c.) was investigated in the mouse hot-plate test. Seven days after a single injection of pertussis toxin, inhibition of morphine and diphenhydramine analgesia was observed, whereas 11 days after pertussis toxin pretreatment, baclofen- and clomipramine-induced antinociception was also reduced. By contrast, pertussis toxin had no effect on physostigmine-induced antinociception. The present results indicate that the activation of pertussis toxin-sensitive G-proteins represents an important transduction step in the central analgesia induced by opioids, antihistaminics, GABAB (gamma-aminobutyric acid B) agonists and tricyclic antidepressants, but not by cholinomimetics.
authors.affiliation: Department of Preclinical and Clinical Pharmacology, University of Florence, Italy.
authors.forename: N
authors.initials: N
authors.lastname: Galeotti
authors.forename: C
authors.initials: C
authors.lastname: Ghelardini
authors.forename: A
authors.initials: A
authors.lastname: Bartolini
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage*; D000818:Animals; D000929:Antidepressive Agents, Tricyclic / Q000494:pharmacology*; D001418:Baclofen / Q000008:administration & dosage; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D002997:Clomipramine / Q000008:administration & dosage; D004155:Diphenhydramine / Q000008:administration & dosage; D004336:Drug Antagonism; D018755:GABA Agonists / Q000008:administration & dosage*; D006634:Histamine H1 Antagonists / Q000008:administration & dosage; D007276:Injections, Intraventricular; D008297:Male; D051379:Mice; D009020:Morphine / Q000008:administration & dosage; D010147:Pain Measurement / Q000187:drug effects*; D037342:Pertussis Toxin; D010830:Physostigmine / Q000008:administration & dosage; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
chemical_list: D000701:Analgesics, Opioid; D000929:Antidepressive Agents, Tricyclic; D002800:Cholinesterase Inhibitors; D018755:GABA Agonists; D006634:Histamine H1 Antagonists; D010566:Virulence Factors, Bordetella; D009020:Morphine; D004155:Diphenhydramine; D010830:Physostigmine; D037342:Pertussis Toxin; D001418:Baclofen; D002997:Clomipramine