Myocardial left ventricular developed pressure (LVDP) at the end of ischemia-reperfusion (I/R), represented as a percentage of equilibration (% of Eq), in hearts of wild-type (WT) and estrogen receptor β knockout (ERβKO) mice of both sexes. M, male; F, female. Deficiency of the ERβ gene decreased postischemic myocardial LVDP in female, but not male, hearts. Results are means ± SE; n = 5 mice/group. *P < 0.05 vs. male WT. #P < 0.05 vs. female WT.