Effects of neuroactive substances on the morphine-induced respiratory depression; an in vitro study

Brain Res. 2000 Nov 24;884(1--2):201-5. doi: 10.1016/s0006-8993(00)02921-8.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylcholine / pharmacology
  • Animals
  • Animals, Newborn
  • Colforsin / pharmacology
  • Drug Interactions / physiology*
  • Efferent Pathways / cytology
  • Efferent Pathways / drug effects*
  • Efferent Pathways / metabolism
  • Haloperidol / pharmacology
  • Indomethacin / pharmacology
  • Morphine / adverse effects*
  • Neurons / drug effects*
  • Neurons / metabolism
  • Neurotransmitter Agents / pharmacology*
  • Quinacrine / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Respiratory Center / cytology
  • Respiratory Center / drug effects*
  • Respiratory Center / metabolism
  • Respiratory Insufficiency / chemically induced*
  • Respiratory Insufficiency / pathology
  • Respiratory Insufficiency / physiopathology
  • Spinal Cord / cytology
  • Spinal Cord / drug effects*
  • Spinal Cord / metabolism
  • Substance P / pharmacology
  • Thyrotropin-Releasing Hormone / pharmacology

Substances

  • Neurotransmitter Agents
  • Colforsin
  • Substance P
  • Thyrotropin-Releasing Hormone
  • Morphine
  • Quinacrine
  • Haloperidol
  • Acetylcholine
  • Indomethacin