Antagonistic effects of taurine and 4-aminopyridine on guinea pig ileum

✍ Scribed by M. E. Arzate; H. Ponce; Herminia Pasantes-Morales

• Publisher: John Wiley and Sons
• Year: 1984
• Tongue: English
• Weight: 518 KB
• Volume: 11
• Category: Article
• ISSN: 0360-4012
• DOI: 10.1002/jnr.490110307

✦ Synopsis

The effects of 4-aminopyridine (4-AP) and of taurine on the guinea pig ileum were examined. Four-AP increases the basal activity from 1.3 to 6.45 cm2/min. This effect is atropine-sensitive and calcium-dependent. Taurine counteracts the effects of 4-AP on muscle contracture in a concentration-dependent manner. In muscles preincubated with 20 mM taurine, the effect of 4-AP decreased about 65%. Taurine added at the time of maximal effect of 4-AP reduced the muscle contracture induced by the drug to the basal levels. Glycine and 0-alanine did not influence the contracture induced by 4-AP, whereas 25 mM y-aminobutyric acid (GABA) reduced it by 30%. Taurine reduced the basal muscle activity by 50% but did not affect the contracture induced by exogenously applied acetylcholine.