title: Effects of (+)-pentazocine on the antinociceptive effects of (-)-pentazocine in mice.
abstract: Previous studies have shown that sigma-1 receptor chaperone (Sig-1R) ligands can regulate pain-related behaviors, and Sig-1R itself can regulate μ-opioid receptor functions as well as signal transduction. Even though (±)-pentazocine has been used clinically for the treatment of pain through opioid receptors, (+)-pentazocine is known to be a selective Sig-1R agonist. To the best of our knowledge, there is no information available regarding the involvement of Sig-1R agonistic action in the antinociceptive effects of (±)-pentazocine. Therefore, the present study was designed to investigate the effects of (+)-pentazocine on the antinociceptive effects of (-)-pentazocine in mice. Both and (-)-pentazocine induced biphasic antinociceptive effects as measured by the warm-plate test. The early phase, but not the delayed phase, of the antinociceptive effects induced by (-)-pentazocine, which are mediated by the activation of μ-opioid receptors, were suppressed by pretreatment with (+)-pentazocine. These results suggest that the innate antinociceptive action of (±)-pentazocine could be marginally reduced by the effects of (+)-pentazocine, but (+)-pentazocine can suppress the antinociceptive effects of (-)-pentazocine at certain time points.
authors.affiliation: Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Tokyo, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Mori
authors.forename: Junpei
authors.initials: J
authors.lastname: Ohya
authors.forename: Toshimasa
authors.initials: T
authors.lastname: Itoh
authors.forename: Yuya
authors.initials: Y
authors.lastname: Ise
authors.forename: Masahiro
authors.initials: M
authors.lastname: Shibasaki
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D000701:Analgesics, Opioid / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D007536:Isomerism; D008297:Male; D051379:Mice; D059225:Nociception / Q000187:drug effects*; D010423:Pentazocine / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000701:Analgesics, Opioid; D010423:Pentazocine
keywords: antinociception; pentazocine; sigma-1 receptor; μ-opioid receptor