Comparison of foetal metabolic differentiation in three cattle muscles
Comparison of foetal metabolic differentiation in three cattle muscles
Hélèn 0
Gagnière 0
Brigitte Pi 0
Catherine Jurie Yves G 0
0 Inra Clermont-Ferrand/Theix , 63122 Saint-Genès-Champanelle , France
- Metabolic differentiation of Serrcitendinosus (ST), Cutaneus trunci (CT) and Masseter (MA) in cattle foetuses aged from 110 to 260 days was studied by measuring isocitrate dehydrogenase (ICDH, oxidative) and lactate dehydrogenase (LDH, glycolytic) activities. The five LDH isoenzymes were separated by electrophoresis and assayed by densitometry. ICDH activity increased from 210 days onwards in the three muscles but more intensively in MA (oxidative). LDH activity increased from 170 days onwards in ST, 180 days onwards in CT and only from 210 days onwards in MA and was higher in the glycolytic muscles (ST and CT). The proportion of the LDH-M subunit increased during foetal life in glycolytic muscles. At 110 days, it was higher in CT, intermediate in ST and lower in MA. These results show that 1) metabolic differentiation of bovine muscle begins during the last third of foetal life and 2) the proportion of the LDH-M subunit seems to be related to the contractile type of adult muscle from the first stages of foetal life. © Inra/Elsevier, Paris. muscle / differentiation / metabolism / cattle / foetus Résumé ― Comparaison de la différenciation faetale métabolique chez trois muscles de bovin. La différenciation métabolique des muscles Semitendinosus (ST), Cutaneus trunci (CT) et Masseter (MA) est étudiée chez des foetus bovins âgés de 110 à 260j. Les activités de l'isocitrate déshydrogénase (ICDH, oxydative) et de la lactate déshydrogénase (LDH, glycolytique) sont mesurées. Les cinq isoformes de la LDH sont séparées par électrophorèse et quantifiées par densitomètrie. L'activité ICDH augmente à partir de 210 j dans les trois muscles, mais de manière plus intense dans le MA (oxydatif). L'activité LDH augmente à partir de 170 j dans le ST, 180 j dans le CT et seulement à partir de' 210 j dans le MA. À 210 j, le ST est le plus glycolytique, le CT intermédiaire, et le MA le moins glycolytique. La proportion de LDH-M augmente tout au long de la vie foetale dans les muscles glycolytiques. À partir de 110 j, elle est plus importante dans le CT, intermédiaire dans le ST et plus faible dans le MA. Ces résultats montrent que 1) la différenciation métabolique des muscles de bovins commence durant le dernier tiers de vie foetale et 2) la proportion de LDH-M semble liée au type contractile dès le début de la vie foetale. © Inra/Elsevier, Paris. muscle / différenciation / métabolisme / bovin / fœtus
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Skeletal muscle is composed of three
main fibre types (I, IIA, IIB), differing by
their contractile and metabolic properties.
In bovine, these different fibre types appear
during foetal life. Previous studies on
contractile differentiation have shown that two
populations of cells are involved in foetal
development of skeletal muscle in cattle [21,
23]. A first generation of cells appears at
39 days of foetal life and matures into type
I fibres at 210 days in all studied muscles.
The second generation, composed of smaller
cells, starts between 90 and 120 days,
depending on the muscle. It gives rise to
IIA and IIB fast fibres in fast adult muscles
and some type I fibres in slow muscles. At
210 days, the second generation is
composed of two categories of cells: fast type
II fibres which still express embryonic and
foetal myosin heavy chain (MHC) and some
type IIC fibres expressing slow and fast
MHCs simultaneously.
In several species (pig, chicken and
rabbit), it has been shown that the energetic
metabolism is mainly oxidative during foetal
life, whereas glycolytic metabolism takes
place during the first weeks after birth [3,
4, 6]. Cattle, a species whose contractile
properties at birth are more mature than
those encountered in other species [21], are
also more advanced in their metabolic
differentiation. Thus, glycolytic activity
increases more quickly than the oxidative
one during foetal life [1]. Oxidative
metabolism decreases between 1 and 12 months,
whereas glycolytic metabolism keeps on
increasing steadily with age [15].
Metabolic differentiation occurs at
different times between muscles. In the
rabbit, muscles involved in posture acquire their
maximum capacity very quickly after birth,
whereas those involved in mobility gradually
acquire their adult profile during postnatal
life [11]. Anaerobic glycolytic activities
increase steadily in rabbit fast muscles until
adulthood, whereas they remain stable in
slow muscles. Aerobic oxidative metabolism
takes place quickly after birth in both the
slow and fast muscles of the chicken, pig
and rabbit. It increases quickly after birth
in slow muscles and then decreases until
adulthood, whereas it decreases steadily in
fast muscles [4, 11, 17]. A full description of
muscle metabolic differentiation during
foetal life in cattle is still lacking.
Therefore, the a (...truncated)