did not reach statistical significancep = 0.8243
The potentiating effects of YM-58483 on endothelial vasodilation cannot be simply attributed to a potential effect on precontraction of 5-HT, since the effect of YM-58483 at 10 μM on the precontraction level in coronary arteries from old rats did not reach statistical significance either in terms of absolute values (4.68 ± 0.47 mN vs. 5.38 ± 1.03 mN for YM-58483 and the vehicle, respectively, n = 12, p = 0.8243) or in terms of the percentage of K + -induced contractions (71.89 ± 7.26% vs. 79.55 ± 6.67% for YM-58483 and the vehicle, respectively, n = 12, p = 0.3820).