Characteristics of compensatory hypertrophied muscle in the rat: II. Comparison of histochemical and functional properties

Abstract

Background We reported that numerous complex branched fibers (CBF) are present in the compensatory hypertrophied plantaris muscle prepared by surgical removal of the synergist muscles in the rat. To investigate the functional effects of these CBF, we examined the histochemical and contractile properties of this muscle. Methods Compensatory hypertrophied plantaris (PLA) muscles were prepared by ipsilateral ablation of synergistic muscle in male Wistar rats. We compared the operated (OP), contralateral (CON‐L), and nonoperated age‐matched normal control (NOR‐C) plantaris muscles. Contractile properties under urethane anesthesia and histochemical properties (myofibrillar ATPase staining) were examined at 6, 10, and 15 weeks after surgical preparation of the muscles. Results The weight of the OP muscle was 48–55% higher than that of the CON‐L muscle. The twitch‐time‐to‐peak tension (TPT) and half‐relaxation time (HRT) were slower in NOR‐C < CON‐L < OP. The shift to slower muscle characteristics was also associated with a similar order (NOR‐C < CON‐L < OP) of histochemical analysis. However, the fatigue resistance capacity of OP (time to 50% fall in tension from initial peak tension during 15‐Hz twitch train) was less than that of CON‐L, in contrast to the results of twitch, tetanus, and histochemical analysis. The order of NOR‐C < CON‐L < OP was not observed in the fatigue‐resistance test. Conclusions Our results suggest that the presence of CBF may disturb the correlation between histochemical and functional properties of the whole muscle. In addition, the CON‐L muscle clearly shifted to slower muscle characteristics, indicating that it was not similar to normal control muscle. © 1996 Wiley‐Liss, Inc.

Compensatory hypertrophy of the teres minor muscle after large rotator cuff tear model in adult male rat

“…Previous reports have shown that the partial loss of function in muscles working in coordination for one function, such as knee extension and ankle flexion, stimulates hypertrophy of the remaining muscle. 1,2,6,26 In these reports, soleus and gastrocnemius tendon ablation resulted in rapid hypertrophy of the remaining plantaris muscle. In the human shoulder, a previous report showed that the existence ratio of TM muscle hypertrophy, evaluated by the CSA of the muscle belly using magnetic resonance imaging, increased in parallel with the extension of the tear size.…”

Artificial oxygen carrier improves fatigue resistance in slow muscle but not in fast muscle in a rat in situ model

“…The jugular vein was dissected and cannulated, and warm Ringer's solution was administered intravenously when necessary. The sciatic nerve and distal tendons of the PLT and SOL muscles were exposed and isolated, and a stainless steel hook was attached to the distal tendon of each muscle using silk ligature as previously reported . At this time point, the femoral artery was exposed to a string but was left intact for normal perfusion (Figure B top), but when occlusion was needed for ischemia, the string was used for ligation (Figure B, bottom).…”

“…Before the measurement of fatigue resistance, twitches were elicited using a single pulse (1 ms duration, 0.5 Hz) electrical stimulation via the sciatic nerve, in order to determine an optimum stimulation voltage to obtain the highest tension (1.5‐4.0 V). Measurement of muscle contractility was performed as in previous reports . Subsequently, peak tetanic tension was determined using stimulation frequencies of 10, 20, 40, 60, 80, 100, and 120 Hz of 0.5‐second duration at 15‐second intervals.…”

“…Moreover, the potential effects of any HBOCs may be influenced by the presence of ischemia compared to under normal circulation. Furthermore, among skeletal muscles, it may be considered that slow‐type muscle such as the soleus (90% < of slow‐type fibers) depends on aerobic metabolism with a high concentration of mitochondria and myoglobin, and may be more affected by ischemia and HBOC than fast‐type muscle such as the plantaris (PLT, 90% < of fast‐type fibers) that depends on anaerobic energy synthesis in cytoplasm containing less myoglobin and mitochondria . Nonetheless, the difficulty in determining reproducible muscle contraction under various in vivo conditions makes the effects of ischemia and HBOC unclear.…”

Possible involvement of IGF-1 signaling on compensatory growth of the infraspinatus muscle induced by the supraspinatus tendon detachment of rat shoulder

“…As an animal model for injury‐induced compensation of skeletal muscle, ablation of the soleus and gastrocnemius muscles in rat has been used (DeVol et al. ; Adams and Haddad ; Tamaki and Shiraishi ). In these studies, it has been reported that the weight of the remaining plantaris muscle was increased significantly.…”