T. Rouaud
University of Nantes
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Featured researches published by T. Rouaud.
Journal of Muscle Research and Cell Motility | 1998
F. Merly; C. Magras-Resch; T. Rouaud; Josiane Fontaine-Pérus; Marie-France Gardahaut
The growth of muscle during postnatal development results partly from the proliferation of satellite cells and their fusion with muscle fibres. We analysed the properties of satellite cells in a heavyweight (HW) turkey strain characterized by high body weight and a fast growth rate, and in a lightweight farm strain (LW) characterized by low body weight and a slow growth rate. Satellite cell activation was then examined in stretched-overloaded anterior latissimus dorsi (ALD) muscle by weighting one wing in young turkeys from both strains. As early as day 1 of stretching for HW and day 2 for LW, small embryonic-like fibres expressing ventricular cardiac myosin heavy chain (MHC) isoform were observed. Following four days of stretching, the number of nascent fibres had increased in both strains but was significantly greater in HW than LW ALD muscle. The proliferation and differentiation capacities of satellite cells from HW and LW strains were investigated in culture. As judged by in vitro measurements of 3H-thymidine incorporation and DNA content, satellite cells of HW turkey exhibited a greater proliferative capability than those of LW turkey. No differences in the temporal appearance of muscle markers (desmin, MHC isoforms) were noted in vitro between the two strains. These data confirm our in vivo observations indicating that selection based on growth rate does not modify muscle fibre maturation. Our in vivo and in vitro observations suggest that variations in the postnatal muscle growth pattern between HW and LW strains may be related to a difference in the capacity of their satellite cells to proliferate.
Histochemical Journal | 1981
J.P. Toutant; T. Rouaud; G. H. Le Douarin
SummaryChick biventer cervicis muscle fibres have been studied histochemically. Fast-twitch, focally innervated (α) fibres represent 70–80% of the total fibres in this muscle. Two histochemical profiles of slow-tonic multi-innervated (β) fibres have been observed from embryonic life to the adult (three-months) stage. These two slow-tonic types differ in the activity of their histochemically demonstrated myofibrillar ATPase after either acid or alkaline preincubation, and after formalin fixation. Both slow-tonic fibre types have a high oxidative metabolism and are PAS-negative. They are referred as toβ1 andβ2R fibre types (slow-tonic oxidative) in an expansion of Ashmores nomenclature, and compared to avian slow-tonic sub-types that have been described in recent reports.β1 andβ2 fibre types exhibit a similar pattern of innervation. Possible explanations of the origin of histochemical heterogeneity in multiple innervated fibres are discussed.
Experimental Neurology | 1983
Didier Renaud; Marie-France Gardahaut; T. Rouaud; Georges Le Douarin
The aim of this work was to study the influence upon differentiation of muscle fiber types of the multiple innervation induced in a fast muscle by chronic spinal cord stimulation. In previous work, we showed that low-frequency stimulation applied to the spinal cord of the chick embryo caused a distributed innervation of muscle fibers in the posterior latissimus dorsi (PLD). In normal development, some beta fibers differentiate within this muscle, the maximal number being attained by 14 to 15 days of embryonic development. Later, the numbers of beta fibers decreased with age. In spinal cord-stimulated embryos the beta muscle fibers within the PLD were stabilized and did not disappear. After the cessation of spinal cord stimulation, the number of beta fibers within the PLD muscle did not decrease. There are possible explanations of the influence of chronic spinal cord stimulation and muscular activity upon formation and persistence of beta fibers within a fast muscle.
Pflügers Archiv: European Journal of Physiology | 1987
Ahmad Khaskiye; Marie-France Gardahaut; C. Fournier Le Ray; T. Rouaud; Didier Renaud; G.H. Le Douarin
The effects of denervation and direct stimulation in fast and slow latissimus dorsii muscles were investigated in chicken. In slow ALD muscle, denervation resulted in an incompleteness of the relaxation, a decrease in MDH and CPK activities and an increase in fast myosin light chains (MLC) accumulation. Direct stimulation at either fast or slow rhythm prevented the effects of denervation on relaxation and CPK activity but was ineffective on MDH activity and fast MLC accumulation. Moreover, direct stimulation of denervated ALD caused rhythm-dependent change in tetanic contraction. In fast PLD muscle, the main changes in muscle properties following denervation were a slowing down of the time course of the twitch and an incompleteness of the relaxation, a decrease in LDH and CPK activities and in LC3F accumulation. Stimulation at a high frequency partly prevented the effects of denervation and resulted in a large accumulation of LC3F, while a low frequency stimulation did not restore the twitch time to peak, increased MDH activity and induced synthesis of slow MLC. This study emphasizes the role of muscle activity and its pattern in some properties of slow and fast chicken muscles following denervation.
Journal of Muscle Research and Cell Motility | 1985
Marie-France Gardahaut; T. Rouaud; Didier Renaud; G. Ledouarin
SummaryLatissimus dorsi muscles of the chick consist of a slow (ALD) and a fast (PLD) muscle. The influence of chronic spinal cord stimulation in the chick embryo upon the expression of myosin light chains and tropomyosin subunits was investigated. Early in development the two muscles exhibited the same ratio of α- and β-tropomyosin subunits. Later, in the slow muscle the ratio β:α decreased and in chicken the amounts of the two components were about the same. In the fast muscle, the α-subunit increased and reached 66% in young chicken. In the early stages of embryonic development, both muscles accumulated slow and fast light chains. However, in ALD the amount of slow light chains was greater than that of fast light chains and the reverse was observed in PLD muscle. Later during development, the slow components decreased in PLD while the fast components increased; the reverse was observed in ALD muscle. The fast myosin LC3f has been detected in 18-day-old embryonic PLD.Chronic spinal cord stimulation at a low rhytm was performed from day 10 of embryonic development to day 15 or 16. In both muscles from spinal cord-stimulated embryos, the β-tropomyosin subunit was lower than in control embryos. In ALD, the pattern of light chains was unaffected by chronic stimulation while in PLD muscle the slow and fast components were modified. In particular the ratio LCs:LCf was increased in spinal cord-stimulated embryos with regard to controls.
Neuroscience Letters | 1983
Marie-France Gardahaut; T. Rouaud; Didier Renaud; Georges Le Douarin
Choline acetyltransferase (CAT) activity of chick latissimus dorsii muscles was studied during embryonic development and at post-hatching states. CAT activity was always higher in anterior (ALD) than in posterior (PLD) muscles. At embryonic stages, chronic spinal cord stimulation at a low rhythm did not modify CAT activity in ALD nerve endings but caused a transient increase in PLD terminals. This increase in CAT activity seems to be related to an acceleration of neuronal maturation rather than to the occurrence of the multiple innervation that results from the central stimulation.
Developmental Biology | 2000
Gwenola Auda-Boucher; Bertrand Bernard; Josiane Fontaine-Pérus; T. Rouaud; Mathias Mericksay; Marie-France Gardahaut
American Journal of Physiology-cell Physiology | 2001
Bodvaël Fraysse; T. Rouaud; Marie Millour; Josiane Fontaine-Pérus; Marie-France Gardahaut; Dmitri O. Levitsky
American Journal of Physiology-cell Physiology | 2001
Bodvaël Fraysse; T. Rouaud; Marie Millour; Josiane Fontaine-Pérus; Marie-France Gardahaut; Dmitri O. Levitsky
Reproduction Nutrition Development | 1988
Marie-France Gardahaut; Ahmad Khaskiye; T. Rouaud; Didier Renaud; G. Le Douarin