title: Effects of neuroactive substances on the morphine-induced respiratory depression; an in vitro study.
abstract: Effects of different neuroactive substances on morphine-induced respiratory depression were studied in medullary respiration-related structures using in vitro brainstem-spinal cord preparation from 1 to 4-day-old rats. Application of morphine (10 microM) reduced respiratory rhythm (fR) as measured by C4 ventral root activity. The depressant effects of morphine were reversed by acetylcholine (10 microM), substance P (50 nM), thyrotropin releasing hormone (TRH) (100 nM) and forskolin (10 microM). The adenosine receptor antagonist, theophylline (100 microM), the dopamine receptors antagonist, haloperidol (10 microM), the cyclooxygenase inhibitor, indomethacin (10 microM) and the phospholipase A(2) inhibitor, quinacrine (10 microM) had no effect on morphine-induced respiratory depression.
authors.affiliation: Department of Anesthesiology and Intensive care, Hokkaido University School of Medicine, Kita-15, Nishi-7, Kita-ku, 060, Sapporo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Takita
authors.forename: E
authors.initials: E
authors.lastname: Herlenius
authors.forename: Y
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: S G
authors.initials: SG
authors.lastname: Lindahl
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D005576:Colforsin / Q000494:pharmacology; D004347:Drug Interactions / Q000502:physiology*; D004525:Efferent Pathways / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D006220:Haloperidol / Q000494:pharmacology; D007213:Indomethacin / Q000494:pharmacology; D009020:Morphine / Q000009:adverse effects*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000494:pharmacology*; D011796:Quinacrine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012125:Respiratory Center / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D012131:Respiratory Insufficiency / Q000139:chemically induced* / Q000473:pathology / Q000503:physiopathology; D013116:Spinal Cord / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D013373:Substance P / Q000494:pharmacology; D013973:Thyrotropin-Releasing Hormone / Q000494:pharmacology
chemical_list: D018377:Neurotransmitter Agents; D005576:Colforsin; D013373:Substance P; D013973:Thyrotropin-Releasing Hormone; D009020:Morphine; D011796:Quinacrine; D006220:Haloperidol; D000109:Acetylcholine; D007213:Indomethacin