title: Mechanisms of pentazocine-induced ventilatory depression and antinociception in anesthetized rats.
abstract: This study was performed to clarify mechanisms underlying pentazocine-induced ventilatory depression and antinociception. Spontaneous ventilation and hind leg withdrawal response against nociceptive thermal stimulation were simultaneously recorded in anesthetized rats. Pentazocine decreased minute volume resulting from depression of the ventilatory rate and tracheal airflow, and prolonged the latency of withdrawal response. Pre-treatment of β-funaltorexamine, but not nor-binaltorphimine, significantly attenuated pentazocine-induced ventilatory depression, while either antagonist weakened its analgesic potency. Comparing with effects of fentanyl and U50488, the present results suggest that ventilatory depression induced by pentazocine is mediated by mainly μ receptors and analgesia by both μ and κ receptors.
authors.affiliation: Laboratory of Neuropharmacology, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya 464-8650, Japan.
authors.forename: Satoko
authors.initials: S
authors.lastname: Kimura
authors.affiliation: Laboratory of Neuropharmacology, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya 464-8650, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ohi
authors.affiliation: Laboratory of Neuropharmacology, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto-cho, Chikusa-ku, Nagoya 464-8650, Japan. Electronic address: haji@dpc.agu.ac.jp.
authors.forename: Akira
authors.initials: A
authors.lastname: Haji
mesh_terms: D000700:Analgesics; D000758:Anesthesia; D000818:Animals; D008297:Male; D009271:Naltrexone / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D010423:Pentazocine / Q000009:adverse effects* / Q000494:pharmacology*; D017208:Rats, Wistar; D017473:Receptors, Opioid, kappa / Q000502:physiology; D017450:Receptors, Opioid, mu / Q000502:physiology; D012131:Respiratory Insufficiency / Q000139:chemically induced* / Q000188:drug therapy
chemical_list: D000700:Analgesics; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; C051843:binaltorphimine; D009271:Naltrexone; C024524:beta-funaltrexamine; D010423:Pentazocine
keywords: Analgesia; Pentazocine; Ventilatory depression