Xylocaine adrenaline

Skeletal muscle biopsies were obtained from vastus lateralis in male patients with heart failure (HF) and in healthy control subjects (HS) (n = 6 + 6). The human HF patients represented the same subtype of HF as in the rat model, that is, postinfarction HF with reduced ejection fraction (HFrEF). Percutaneous needle biopsies were performed under sterile conditions with local anesthesia (Xylocaine–Adrenaline, 10 mg mL⁻¹ + 5 μg mL⁻¹, AstraZeneca, Oslo, Norway) using a 6‐mm Pelomi needle (Albertslund, Denmark) with manual suction, and the biopsies were frozen in isopentane on dry ice and stored at −80°C. Age and weight was not different between HF patients and HS (HF 67 ± 2 vs. HS 70 ± 3 years old; HF 82 ± 7 vs. HS 87 ± 4 kg), while HF patients had reduced ejection fraction (HF 28 ± 4 vs. HS 68 ± 1%, P < 0.001) as well as lower maximal oxygen uptake (HF 19 ± 3 vs. HS 28 ± 2 mL kg⁻¹ min⁻¹, P < 0.05). HF patients had reduced skeletal muscle peak torque (HF 136 ± 10 vs. HS 168 ± 12 Nm, P < 0.05) and peak power (HF 27 ± 3 vs. HS 35 ± 3 W, P < 0.05) of vastus lateralis compared to HS. The human subjects in this study were a subset of participants from a previous study from our laboratory, and details about the methodology, testing regime, and inclusion/exclusion criteria have been described (Munkvik et al. 2010).

Muscle biopsies are obtained from the midsection of the vastus lateralis muscle under local anesthesia (xylocaine adrenaline, 10 mg·ml^-1 + 5 μg·ml^-1, AstraZeneca). Briefly, a 1-2-cm incision will be made in the skin and the fascia of the vastus lateralis muscle. Biopsies are collected using a 6-mm Pelomi needle (Bergström technique) with manual suction to obtain muscle samples (~200 mg). Biopsies will be rinsed in ice cold saline (0.9% NaCl) and carefully dissected free of visual fat, connective tissue, and blood. All pieces but 2 will be frozen in isopentane, precooled on dry ice, and stored at –80 °C for later analysis. The last 2 pieces (~10 mg) will be transferred to 500 μL of RNAlater stabilization solution (Invitrogen) and stored at 4 °C for at least 24 hours before 1 piece is transferred to –20 °C for long-time storage while the RNAlater solution is removed from the last piece before long-term storage at –80 °C.