Effect of denervation on glycogen metabolism in fast and slow muscle of rat

Abstract

The postdenervation changes in glycogen metabolism were explored in fast (extensor digitorum longus, EDL), and slow (soleus, S) muscle of rat. During the first 12-14 hours after denervation, glycogen accumulates to a similar content in the two muscles, an effect reproduced by paralysis. Increase in the molecular weight of glycogen and decrease in the turnover rate of similar degree occur. During the ensuing 12-24 hours the glycogen concentration decreases in EDL (but not in S). This decrease is influenced by factors such as muscle type, longer or shorter nerve stump, age, and previous training of the animal. In both EDL and S, the rate of glucose incorporation into glycogen and the glycogen synthase [l/(l + D)] activity were depressed by denervation. The cAMP concentration increased 36 hours after denervation. This may have consequences on the muscle sensitivity to hormones. In fact, at this time, insulin did not increase glycogen synthase I activity or the glycogen content (with the exception of glycogen in S) and the effects of epinephrine on glycogen metabolism became more significant.

Heart transplantation changes the expression of distinct gene families

“…19). Numerous biochemical changes occur in mammalian skeletal muscle following denervation (11,34). These changes include metabolic alterations that reflect depressed energy production, such as decreased levels of several enzymes involved in oxidative metabolism, decreased oxygen consumption, decreased metabolic rate, and altered mitochondrial integrity (references in Ref.…”

Energy metabolism in amyotrophic lateral sclerosis: assessment of body composition and energy expenditure

“…Abnormal glucose metabolism has been observed in tissues distant from the site of denervation in animal studies (Nunes and de Mello, 2005). Studies of denervated rats show a generalized reduction in glucose uptake, glycogen synthesis, insulin sensitivity (Nunes and de Mello, 2005) and an enhanced effect of epinephrine on glycogen metabolism (Moruzzi and Bergamini, 1983).…”