Metabolism of red and white muscle fiber groups

Abstract

Rat adductor fiber groups, predominantly composed of either red or white muscle fibers, have been utilized to demonstrate metabolic differences in these two types of voluntary skeletal muscle. Glycogen concentrations of muscle obtained immediately after sacrificing the rats were higher in white than in red muscle, but at the end of 2-hr incubation this relationship was reversed. No difference could be demonstrated in glucose uptake in the two types of muscle, while lactate production was greater in white than in red muscle. Acetoacetic acid uptake by red muscle was higher than that by white muscle as measured by chemical analysis and uptake of acetoacetic acid-C14. A lower percentage of acetoacetic acid-C14 uptake appeared in the lactate fraction in white as compared to red muscle fiber groups. In the case of glycogen, this relationship was reversed and a larger percentage of C14 uptake appeared in the glycogen fraction of white as compared to red muscle. Oxygen uptake and the counts from acetoacetic acid-C14 appearing in C14O2 were higher in red than in white muscle. The creatine phosphate level, after 2-hr incubation, was higher in white muscle. These data demonstrate striking differences in the relative distribution of various metabolic pathways in red and white muscle.

Significance of the increase in glucose 6‐phosphatase activity in skeletal muscle cells of the mouse by starvation

“…The role of glucose from muscle glycogen, even if present in small amounts, is probably to elevate the glucose level, which is inclined to be low in the blood of starved animals. Beatty et al (1963) and Bocek et al (1966) reported that the glycogen content in white muscles is larger than that in red muscles. We recently found that G6Pase activity is higher in a white muscle (m. gastrocnemius) than in a red muscle (m. soleus) .…”

Age Change of Skeletal Muscles of Rats

“…G a u t h ier and P a d y k u la [4] reported that red fibers have high metabolic activity and white ones lower activity. Besides, there have been many papers on the morphologic, physiologic and enzymatic differences between the two kinds of muscle fibers [1,2,6,11], T a u c h i [9,10], examining various kinds of organs and tissues of human autopsy cases and of experimental animals, discussed the differences in grade of senile atrophy according to the kinds of organs and tissues and concluded that the senile atrophy of the tissue actively functioning for maintenance of life was not due to decrease in volume of the parenchymal cells but due mainly to decrease in number of the cells and that in the senile atrophy of other tissues there was noted a distinct decrease in volume of the cells.…”

Propriétés des fibres musculaires squelettiques. 1. Influence de l'innervation motrice

“…Nous nous intéresserons dans ce chapitre à définir les propriétés des fibres qui ont permis de les classer : c'est-à-dire essentiellement les critères métaboliques et fonctionnels (Guth, 1972 (Needham, 1926). Les premiers travaux faisant intervenir des notions de biochimie métabolique montrè-rent que les muscles blancs, capables de contractions rapides et brèves, utilisent essentiellement la glycolyse pour couvrir leurs besoins énergétiques (Ogata, 1960 ;Beatty et al, 1963 ;Blanchaer et al, 1963 ;Bacou, 1972 ;Ansay, 1974 ; Lefaucheur et Vigneron, 1986) alors que les muscles rouges, qui peuvent se contracter pendant de longues périodes, puisent principalement leur énergie dans les mécanismes oxydatifs (Domonkos et Latzkovits, 1961 ;Bacou et Baldwin, 1979 (Essen et al, 1975;Spamer et Pette, 1977 ;Lowry et al, 1978 ;Lowry, 1984).…”