(A) Chemical structures of JK-1 and control. Hydrolysis of JK-1 yields H2S and the chemical backbone of JK-1, which was selected as Control. The control compound is devoid of sulfur and does not release H2S. (B) Experimental design and protocol. At 1 week following baseline echocardiography, mice were subjected to TAC or sham TAC surgery. Mice were studied for a period of 18 weeks following TAC. The H2S donor, JK, was administered at either 3 or 10 weeks following TAC at a dose of 100 μg/kg b.i.d. through i.p. injection. This study involved 4 groups: sham TAC, HF plus Control compound, HF plus JK-1 administered at 3 weeks following TAC, or HF plus JK-1 administered starting at 10 weeks post TAC. b.i.d. = twice daily; BNP = B-type natriuretic peptide; HF = heart failure; LV = left ventricle; RAAS = renin-angiotensin-aldosterone system; TAC = transverse aortic constriction.