Apoptosis of skeletal muscle myofibers and interstitial cells in experimental heart failure

Congestive heart failure (CHF) is characterized by a limb skeletal muscle myopathy with shift from the slow aerobic, fatigue resistant fibers, to the fast, anaerobic ones, and muscle bulk loss. Apoptosis (A) has been recently demonstrated to play a role in several cardiovascular diseases. Aim of the study: we have investigated the role of A in the skeletal muscle of the hindlimbs in an experimental model of CHF. Animals and methods: CHF was induced in 7 males 80-100 g Sprague-Dawley rats with 30 mg/kg monocrotaline. Five age and diet matched controls were also studied. The time course of A was also studied in additional animals at day 0, 17, 24 and 30 days. Results: At day 27 the electrophoretic analysis of myosin heavy chains (MHCs) demonstrated in the CHF rats the occurrence of a myopathy, with disappearance of slow MHC1 in the Tibialis Anterior (TA), and a significant shift from the slow to the fast isoforms in the soleus and EDL. With in situ DNA nick-end labelling (TUNEL) we found...