Myoglobin in rat hind limb muscles after denervation and during reinnervation

Abstract

Radioimmunoassay of myoglobin (Mb) was performed in rat hind limb muscles after surgical denervation and during reinnervation following cryolesion of the sciatic nerve. Muscles of the contralateral leg served as controls. After resection of the sciatic nerve, decreased Mb concentrations were noted on the fourth day in the tibialis anterior, peroneus longus, and extensor digitorum longus (EDL) muscles. Thereafter, the levels increased up to the last observation on day 32. The increases in Mb levels in the tibialis anterior and EDL muscles were considerably more pronounced (305% and 324%, respectively) than in the peroneus longus and soleus muscles (148% and 137%, respectively). After cryolesion of the sciatic nerve, the Mb concentrations in the tibialis anterior, peroneus longus, and EDL muscles increased, reaching maximal values on days 16-21. The levels then decreased and normal values were observed 2 months postoperatively. The normalization of the Mb levels during reinnervation corresponded fairly well in time with the clinical recovery and neurophysiological findings observed in a previous study.

Induction of carbonic anhydrase III mRNA and protein by denervation of rat muscle

“…However, the induction of expression of CAIII in EDL and AT to values close to those found in the normal adult soleus muscle suggests that the change perhaps reflects a fast-to-slow transition. This agrees with various other reports in the literature; for example, myoglobin, a protein usually confined to type 1 fibres, is increased 3-fold in denervated EDL and AT (Askmark et al, 1984), to values higher than those found in fetal tissue (Weller et al, 1986) and similar to those of adult soleus. In addition, the synthesis of parvalbumin, characteristic of type 2 fibres, is decreased after denervation to a value characteristic of slow-twitch muscle (Leberer & Pette, 1986).…”

“…The low contents of parvalbumin in fetal and adult soleus are unaffected by denervation (Leberere & Pette, 1986). Furthermore, the denervated soleus is apparently slow to lose proteins characteristic of type 1 fibres, since little change is seen in the CAIII or myoglobin protein contents during the 32 days after denervation (Askmark et al, 1984; the present work). Eventual loss of CAIII protein from denervated soleus is presumably heralded by the decrease of CAIII mRNA to 30 % of control values.…”

“…Both muscles comprise predominantly type 2 fibres, but there are some type I fibres in the AT and a higher proportion of type 2A (intermediate) than 2B (fast) in AT compared with the EDL (Jeffery et al, 1986a;Wistrand et al, 1987). It is noteworthy that a similar variation in the extent of myoglobin induction among denervated muscles of similar fibre composition has also been reported (Askmark et al, 1984).…”

“…The band of Mr 29000, previously defined as CAIII by using a specific antibody (Lloyd et al, 1985), is strikingly increased in the denervated AT and EDL samples compared with the controls, but is slightly less prominent in the soleus muscle. At least five other polypeptides can be seen to be increased in the denervated AT and EDL compared with the controls, including the Mr-17 000 polypeptide, previously identified as myoglobin (Askmark et al, 1984), and several other components are less prominent after denervation. The soleus polypeptide pattern is relatively unchanged overall by denervation.…”

Effect of sepsis on skeletal muscle oxygen consumption and tissue oxygenation: interpreting capillary oxygen transport data using a mathematical model

“…ٌP ͪͬ (3) where ␣ and D are the tissue oxygen solubility and diffusivity and c Mb , D Mb , and S Mb are the Mb concentration, diffusivity, and oxygen saturation. Michaelis-Menten consumption kinetics are used to describe the PO 2 -dependent V O 2 , M(P) ϭ M 0 P/(P ϩ P c ), and Mb saturation is given by S Mb (P) ϭ P/(P ϩ P 50,Mb ).…”