The expressions of insulin receptor β and phospho-S636 insulin receptor substrate 1 in human valve interstitial cells were increased by fructose at high concentration. Representative gels and densitometric analyses of (A) PI3K p85 (B) total AKT (C) phospho(p)-S473-AKT (D) pT308-AKT (E) insulin receptor substrate 1 (IRS1), and (F) p-S636 IRS1 detected at 24 h incubated with 0, 2, or 20 mM fructose. Values are mean ± SEM, n = 4–6 in each experimental group. The sample size of each group was noted on the bar. ∗p < 0.05, ∗∗p < 0.01 versus 0 mM fructose group using the nonparametric, Kruskal–Wallis test followed by the Dunn post hoc method.