title: Histochemical differentiation of fibers in the rat slow and fast twitch muscles.
abstract: Wistar male rats were sacrificed at 1, 3, 5, 7, 9, 11, 13, 15, 17, 19, and 21 days, and at 5 and 10 weeks of age. The histochemical differentiation of slow twitch soleus and fast twitch plantaris muscle fibers was examined from the enzyme activities of adenosine triphosphatase (slow- or fast-contracting), succinate dehydrogenase (high- or low-oxidative), and alpha-glycerophosphate dehydrogenase (high- or low-glycolytic). The soleus muscle fibers differentiated into slow-contracting (S) and fast-contracting (F) fibers at 7 days of age. In the plantaris muscle, differentiation into S and F fibers in the deep portion occurred earlier (9 days) than in the superficial portion (11 days). Thereafter, fiber type shifts between S and F were observed in both muscles. Differentiation into fast-contracting oxidative glycolytic (FOG), fast-contracting glycolytic (FG), and slow-contracting oxidative (SO) fibers occurred in both muscles at 15 and 17 days of age. After subdivision into the three fiber types, a type shift from FOG to FG was observed in both the deep and superficial portions of the plantaris muscle.
authors.affiliation: College of Liberal Arts and Sciences, Kyoto University, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Ishihara
authors.forename: S
authors.initials: S
authors.lastname: Taguchi
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D005993:Glycerolphosphate Dehydrogenase / Q000378:metabolism; D006651:Histocytochemistry; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D024510:Muscle Development; D009132:Muscles / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D013385:Succinate Dehydrogenase / Q000378:metabolism
chemical_list: D005993:Glycerolphosphate Dehydrogenase; D013385:Succinate Dehydrogenase; D000251:Adenosine Triphosphatases