The relationship between the dimensions of the fibres and the number of nuclei during restricted growth, degrowth and compensatory growth of skeletal muscle

Abstract

During unrestricted growth of the pectoral muscle of chickens, the mean cross-sectional area of the fibres increased in proporiton to the total number of nuclei and in proportion to the two thirds power of the weight of the muscle. Continuous restricted feeding from 0 day, which limited the weight of the muscle at 16 days to 44% or 69% of that of chickens fed ad libitum, did not affect these relationships.A sudden restriction of feed from eight days of age retarded growth of the muscle to approximately 70% of the weight of the controls at 16 days. It did not affect the relationship between the number of nuclei and the fibre cross-sectional area, both of which were also limited to about 70% of those of the controls; but it did disrupt the relationship of these two variates to the weight of the muscle. Subsequent ad libitum feeding caused compensatory growth and restored the relationship.Starvation or severe undernutrition for a few days, which reduced weight of the muscle and the fibre cross-sectional area by approximately 2 5 % , caused no loss of nuclei, thereby disrupting both relationships. Subsequent ad l i b i t u m feeding initially caused an increase of muscle weight and fibre cross-sectional area but no increase in the number of nuclei. This restored the relationships, which were then maintained during subsequent compensatory growth.

Histochemical and Morphometric Evaluation of Skeletal Muscle of Cachectic Sheep

“…Resistance to disuse atrophy can be seen in intact, innervated muscle by maintaining or by strengthening antagonistic muscles [29]. Some information is available on the morphological effects of reduced nutrition on muscle fibers, one of which is to increase the ratio of fiber size to nuclear number [26]. Advanced cachexia, and particularly that associated with neoplasia, leads to marked fiber size disparities [2,3,4 I].…”

Influence of castration and postnatal energy restriction on the contractile and metabolic characteristics of bovine muscle

“…The size of the different fiber types is, in contrast, always decreased after a period of energy restriction, whether it be before or after weaning (Moss, 1971;Haltia et al, 1978;Goldspink and Ward, 1979;Bedi et al, 1982;Burwin et al, 1988;Lanz et al, 1992). This diminution is due to a decrease in muscle DNA and protein content (Moss, 1971;Ward and Stickland, 1993) Morgan (1972), who stated that undernutrition at the beginning of postnatal life had no effect on the quality of meat, as had been suggested in an early study by Winchester and Ellis (1956 Undernutrition between birth and weaning had temporary effects on the distribution of type I and type IIB fibers.…”

In ovotemperature manipulation differentially influences limb musculoskeletal development in two lines of chick embryos selected for divergent growth rates

“…Primary fibres form between embryonic days (ED) 4 and 7 followed by a second wave of myoblast proliferation and differentiation to form secondary fibres between ED8 and 16 (Crow and Stockdale, 1986;Lee et al, 2004). Muscle fibre formation ends by hatch (ED21) (Smith, 1963), after which muscle growth and regeneration occurs through the activation of undifferentiated muscle precursor cells known as satellite cells (Moss, 1968). Pax7 has been shown to play an essential role in embryonic satellite cell specification as well as in their survival during the perinatal period (Buckingham, 2007).…”