Fig. 4.

Inhibitory effect of isovanillin on tension development in the isolated ileum of rat treated with 5- HT (2 μM), acetylcholine (ACh, 500 nM) and electrical field stimulation (EFS: 6 V, 50 Hz, 1 s duration). Each data point is mean ± SEM (n=6). Ordinant scales: spasm remaining as a % of the contraction prior to isovanillin addition. Abscissa scales: log₁₀ concentration of isovanillin. Each point is mean and the vertical lines show the SEM. EFS-1= initial contractile response. EFS-2= secondary contractile response. The variation in ACh response is not statistically significant but inhibition of 5-HT and EFS responses are significant (P<0.001, ANOVA).