[Stimulating effects of alanine and glycine on guinea-pig taenia coli (author's transl)].
Effects of alanine and glycine on the mechanical and electrical activities of guinea-pig taenia coli were investigated. Alanine (0.1--10 mM) and glycine (0.5--10 mM) produced a dose dependent contraction of guinea-pig taenia coli. The stimulating effects of alanine and glycine were not inhibited in the presence of atropine (5 muM), tetrodotoxin (0.1 micrograms/ml), diphenhydramine (4 muM), methysergide (3 muM), strychnine (10 muM), and were not influenced by treatment with indomethacin (3 muM). However, these effects were inhibited in the presence of a Ca antagonist, verapamil (10 muM). When the electrical activities of the taenia coli were recorded by the single sucrose-gap method, alanine and glycine (5--10 mM) produced a reduction of membrane potential and increased spike heights and frequencies of action potential. In LiCl or Choline-Cl and in Na-isethionate solutions, the stimulating effect of alanine was not abolished, but was completely inhibited in KCl-depolarized preparation. From these results, it is considered that both alanine and glycine may directly produce contraction by a depolarization of the cell membrane of guinea-pig taenia coli.
D000200:Action Potentials / Q000187:drug effects; D000409:Alanine / Q000494:pharmacology*; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002118:Calcium / Q000037:antagonists & inhibitors; D002713:Chlorine / Q000494:pharmacology; D003106:Colon / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D005998:Glycine / Q000494:pharmacology*; D006168:Guinea Pigs; D006634:Histamine H1 Antagonists / Q000494:pharmacology; D066298:In Vitro Techniques; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D011453:Prostaglandins / Q000502:physiology; D012702:Serotonin Antagonists / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology; D013331:Strychnine / Q000494:pharmacology; D013779:Tetrodotoxin / Q000494:pharmacology
D006634:Histamine H1 Antagonists; D011453:Prostaglandins; D012702:Serotonin Antagonists; D013779:Tetrodotoxin; D002713:Chlorine; D001285:Atropine; D012964:Sodium; D013331:Strychnine; D000409:Alanine; D002118:Calcium; D005998:Glycine