[Sensitivity of neurons of the myenteric plexus to opiate alkaloid morphine].
With the aid of sucrose gap method, sensitivity of the myenteric plexus' neurons was studied in the neural-muscular preparation which included the myenteric plexus and circular smooth muscle layer. Morphine (10(-4)-10(-8) g/ml) produced an excitation as revealed in depolarization of the smooth muscle cell membrane, in the increase of AP frequency and amplitude as well as of the duration of contractions. Incubation of the preparation in the solution containing M- and N-cholinergic blocking drugs (10(-5) g/ml atropine and 5 X 10(-6) g/ml benzohexonium) and preadministration of the antagonist of opiate receptors naloxone (3 X 10(-7) g/ml) did not change the character of morphine action, whereas administration of serotonin antagonist methysergide (5 X 10(-6) g/ml) eliminated the excitatory effects. These changes in electrical and contractile activity of the preparation after morphine administration seem to be connected with an increasing release of serotonin.
D000200:Action Potentials; D000818:Animals; D002432:Cecum / Q000294:innervation; D003470:Culture Media; D006168:Guinea Pigs; D066298:In Vitro Techniques; D009020:Morphine / Q000494:pharmacology*; D009119:Muscle Contraction; D009130:Muscle, Smooth / Q000502:physiology*; D009197:Myenteric Plexus / Q000166:cytology*; D009469:Neuromuscular Junction / Q000166:cytology*; D009474:Neurons / Q000187:drug effects* / Q000502:physiology; D011957:Receptors, Opioid / Q000187:drug effects* / Q000502:physiology
D003470:Culture Media; D011957:Receptors, Opioid; D009020:Morphine
Chuvstvitel'nost' neironov miénteral'nogo spleteniia k opiatnomu alkaloidu morfinu.