37 patients with severe CHF were randomized to 12 weeks of ET or sedentary lifestyle (control). The expression of Rnf28 and Atrogin-1 in the skeletal muscle was analyzed by RT-PCR and Western blotting. Skeletal muscle cross sectional area (CSA) was measured by computed tomography.
In CHF patients ET led to a significant reduction in skeletal muscle mRNA transcription (from 14.3 ¡À 2.0 to 8.7 ¡À 1.4 arbitrary units; p < 0.05 versus baseline and versus control for the change) and protein expression of Rnf28 (from 4.70 ¡À 1.35 to 2.84 ¡À 0.65 arbitrary units; p < 0.05 versus baseline and versus control for the change). This was accompanied by a significant increase in total muscle CSA of both thighs (from 139.9 ¡À 5.2 to 149.2 ¡À 5.9 cm2; p < 0.05 versus baseline and versus control for the change). On the contrary, Atrogin-1 was not affected.
In patients with advanced CHF, regular physical exercise training led to a decrease in Rnf28 expression in the skeletal muscle. This was linked to an increase in skeletal muscle cross sectional area, supporting the notion that ET has anti-catabolic properties in CHF.