Fig. 2.

Spinotrapezius muscle PO₂mv responses from representative CHF and CHF + EXT rats under sodium nitroprusside (SNP) and N^G-nitro-l-arginine methyl ester (l-NAME) superfusion conditions. Time zero denotes the onset of muscle contractions. Note that SNP slowed PO₂mv kinetics to a greater extent in CHF + EXT compared with CHF rats. l-NAME did not alter PO₂mv kinetics in either group but reduced the contraction steady-state PO₂mv only in CHF + EXT rats when compared with control. Therefore, CHF + EXT rats continued to exhibit slower PO₂mv kinetics than their sedentary counterparts during the l-NAME condition. PO₂mv kinetics parameters are shown in Table 3 and Fig. 4.