ZP2495 Protects against Myocardial Ischemia/Reperfusion Injury in Diabetic Mice through Improvement of Cardiac Metabolism and Mitochondrial Function: The Possible Involvement of AMPK-FoxO3a Signal Pathway

Figure 5

ZP2495 improved mitochondrial function and biogenesis in the myocardium of db/db mice subjected to I/R. (a) Representative transmission electron micrographs of mitochondria in the LV myocardium. Original magnification ×10,000 (scale bar = 1 μm) (A1) and ×40,000 (scale bar = 250 nm) (A2). (b–d) Respiration in freshly isolated heart mitochondria from each group mice was analyzed with a SeaHorse XF96 analyzer. Mitochondria were assayed under state 4, that is, substrate but no ADP (sometimes also referred to as state 2), and state 3, that is, substrate and ADP present respiration (VO₂) with substrates from complex I (5 mmol/L G/M) (b), complex II (5 mmol/L Succ and 1 mmol/L rotenone) (c), and complex IV (0.5 mmol/L N,N,N9,N9-tetramethyl-p-phenylenediamine (TMPD) and 3 mmol/L sodium ascorbate) (d). State 3 was induced with 1 mmol/L ADP in all cases. (e) The RCR was determined as the ratio of state 3 to state 4. The bars plotted correspond to replicates from two experiments. (f) Relative ATP level change in different treatments. Sham: BKS + sham group; db/db: db/db + sham group; I/R: db/db + I/R group; ZP2495: db/db + I/R + ZP2495 group; glucagon: db/db + I/R + glucagon group; and ZP131: db/db + I/R + ZP131 group. Presented values are mean ± SEM. versus the sham group; versus the db/db group; ^$ versus the db/db + I/R group; and ^£ versus the db/db + I/R + ZP2495 group.

(a)

(b)

(c)

(d)

(e)

(f)