Stimulating effects of alanine and glycine on guinea-pig taenia coli
Ishizawa, M.; Miyazaki, E.
Nihon Heikatsukin Gakkai Zasshi 15(1): 29-35
1979
ISSN/ISBN: 0374-3527 PMID: 40057 Document Number: 149703
Effects of alanine and glycine on the mechanical and electrical activities of guinea pig tenia coli were investigated. Alanine (0.1-10 mM) and glycine (0.5-10 mM) produced a dose-dependent contraction of guinea pig tenia coli. The stimulating effects of alanine and glycine were not inhibited in the presence of atropine (5 .mu.M), tetrodotoxin (0.1 .mu.g/ml), diphehydramine (4 .mu.M), methysergide (3 .mu.M), strychnine (10 .mu.M) and were not influenced by treatment with indomethacin (3 .mu.M). These effects were inhibited in the presence of a Ca antagonist, verapamil (10 .mu.M). When the electrical activities of the tenia 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 a KCl-depolarized preparation. Both alanine and glycine may directly produce contraction by a depolarization of the cell membrane of guinea pig tenia coli.