title: Histochemical development of myofibres in neonatal piglets.
abstract: The periodic acid-Schiff (PAS) reaction and tests for glycogen phosphorylase, oxidative enzymes and acid-stable and alkali-stable adenosine triphophatase (ATPase) were used to determine the degree of histochemical differentiation between myofibres of sartorius muscles from neonatal piglets. Within 24 h of birth, the ratio of myofibres with acid-stable ATPase to those with acid-labile ATPase was 1:21-0. By 10 days the ratio had changed to 1:5-2. Mean minimum myofibre diameters (all histochemical types combined) increased steadily after birth although diameters of myofibres with acid-stable ATPase showed no increase until 6 days. By 10 days, consistent differentiation was observed with the alkali-stable ATPase and glycogen phosphorylase reactions but not with the PAS reaction. During the 10 day neonatal period, all types of myofibres contained large or moderate numbers of mitochondria.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D000831:Animals, Newborn / Q000254:growth & development* / Q000378:metabolism; D006651:Histocytochemistry; D006863:Hydrogen-Ion Concentration; D008928:Mitochondria / Q000201:enzymology; D024510:Muscle Development; D009132:Muscles / Q000201:enzymology / Q000378:metabolism*; D009246:NADH Tetrazolium Reductase / Q000378:metabolism; D006005:Phosphorylases / Q000378:metabolism; D012155:Reticulin / Q000378:metabolism; D013552:Swine / Q000254:growth & development* / Q000378:metabolism
chemical_list: D012155:Reticulin; D009246:NADH Tetrazolium Reductase; D006005:Phosphorylases; D000251:Adenosine Triphosphatases