Postischemic coronary flow (CF) (A), left ventricular developed pressure (LVDevP) (B), +dLVP/dtmax (C), −dLVP/dtmax (D) and left ventricular diastolic pressure (LVDiastP) (E) in isolated WT and S1P3 knock-out (KO) mouse hearts without (left panels: A1–E1) or with S1P administration (middle panels: A2–E2) for 5 min to the perfusate at 10−6 M before the induction of a 20-min ischemia followed by a 120-min reperfusion period. The right panels (A3–E3) demonstrate statistical comparison of the parameters captured at the end of the reperfusion period. Mean ± SEM; n = 6, 8, 7, 7; * p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001, with two-way repeated measurement ANOVA and Dunnett’s post hoc test in the graphs and two-way ANOVA followed by Sidak’s post hoc test in the table insets.