Conversion of muscle fiber types in regenerating chicken muscles following cross-reinnervation

Abstract

Slow-tonic anterior latissimus dorsi (ALD) and fast-twitch posterior latissimus dorsi (PLD) muscles of 7 to 10-day-old White Leghorn chickens were crushed and allowed to be reinnervated by their own nerve, or crushed and transplanted to the other side and allowed to be reinnervated by the nerve of the side to which they were transplanted. Following transplantation, changes in the weight of the muscle, fiber-type composition and innervation pattern during regeneration were investigated. Normal growth rate of PLD was about twice that of ALD. Regenerating PLD, however, atrophied rapidly after crushing and denervation whether innervated by its own nerve or the other nerve type, whereas ALD reinnervated by its own nerve showed marked hypertrophy. PLD fibers transformed rapidly to fast-twitch alpha or slow-tonic (ST) fibers when they were reinnervated by PLD or ALD nerve, respectively. When ALD fibers were reinnervated by their own nerve, they differentiated into ST fibers that were surrounded by smaller immature fibers. ALD fibers were, however, resistant to complete control by fast-twitch PLD nerve and contained a large number of slow fibers (ST and beta) long after transplantation. Slow fibers in regenerates were initially multiply innervated, but later transformed into fast-twitch alpha fibers that were focally innervated. The mode of differentiation and innervation pattern of different muscle fiber types in regenerating muscles are discussed.

In Vivo Low‐level Light Therapy Increases Cytochrome Oxidase in Skeletal Muscle

“…Such change is detectable as early as 1 h after a single bout of exercise (57,58). White‐to‐red fiber conversion has been described in response to exercise (59) and other interventions associated with increased intracellular energetic expenditure such as electrical stimulation (60), cross‐reinnervation (61), a diet rich in carnitine, carnosine and taurine (62), beta adrenergic stimulation (63), androgen receptor antagonism (64) and mild heat stress (65). However, the results of this study are limited to describing an up‐regulation of oxidative capacity as measured by cytochrome oxidase activity.…”

Sensitivity of cultured and skinned chick myotube to calcium, strontium, and barium ions examined by recording isometric contractions

“…Almost all the fibers of the ALD and pectoralis muscles are shown to be slow tonic fibers (98%, Kikuchi et al, 1986) and fast twitch fibers (98%, Nonaka and Sugita, 1981), respectively. ALD muscle fiber was more sensitive than the pectoralis muscle fiber to Ca2+, Sr2+, and Ba2+ for contraction, especially to the latter two ions (Fig.…”

Posthatching changes in levels and molecular forms of acetylcholinesterase in slow and fast muscles of the chicken: Effects of denervation and direct electrical stimulation

“…Furthermore, direct electrical stimulation of denervated ALD was ineffective in preventing the postdenervation changes in AChE-molecular-form distribution. It has been reported that denervated ALD muscle does not respond as well to electrical stimulation as PLD muscle does, with respect to myosin light chains and to oxidative activity [19]; furthermore, it exhibits less plasticity for transformation after cross-reinnervation experiments [20]. The differential response of ALD muscle to denervation, cross-reinnervation and to direct electrical stimulation emphasizes the existence of intrinsic differences between fast PLD and slow ALD muscles.…”