Figure 4. Hearts from ssTnI mice exposed to TAC demonstrate robust metabolic remodeling.

Representative spectra showing the end-point enrichment of ¹³C into the glutamate pool from NTG TAC and ssTnI TAC hearts perfused with ¹³C palmitate (A). The fractional contribution of palmitate (B) (n=6–9) and glucose (C) (n=6–9) to acetyl CoA production was determined by ¹³C end–point enrichment of the glutamate in acid soluble extracts. The protein expression of PDK4 was determined (D) (n=3) and shown to be downregulated by TAC in ssTnI mice. The phosphorylation of PDH (phos-PDH) (E) (n=5–6) was downregulated by TAC in ssTnI mice, while PDH expression was not affected (F) (n=5–6). Data is mean±SE. *p<0.05 vs. NTG sham, #p<0.05 vs. ssTnI sham. Sham hearts indicated by open bars; hearts undergoing TAC indicated by solid bars.