The effect of 4-aminopyridine-induced increased neuromuscular activity on the metabolism of developing muscles in chick embryos.
Chick embryos were treated with 4-aminopyridine (4 X 100 micrograms) during a critical stage of muscle development, and the effect of enhanced neuromuscular activity upon energy metabolism was studied in two fast-twitch muscles and a slow-tonic muscle. In the slow-tonic muscles of treated embryos, the specific activities of creatine kinase (CK) and lactate dehydrogenase (LDH) were reduced by 11 and 21%, respectively, compared with control values, whereas the ratios of the CK-MB isoforms and the LDH-H subunits increased to 125 and 135% of the control values, respectively. No significant changes could be shown in the enzymatic pattern of fast muscles. These results indicate that a moderate increase in neuromuscular activity of the chick embryo primarily influences the metabolism of developing slow muscles, promoting the development of an enzyme profile characteristic of slow oxidative fibres.
Keresztes
M
M
Takács
O
O
Guba
F
F
D015761:4-Aminopyridine; D000631:Aminopyridines / Q000494:pharmacology*; D000818:Animals; D002642:Chick Embryo; D003402:Creatine Kinase / Q000378:metabolism; D004734:Energy Metabolism; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D009132:Muscles / Q000196:embryology* / Q000378:metabolism; D009469:Neuromuscular Junction / Q000187:drug effects*
D000631:Aminopyridines; D007527:Isoenzymes; D015761:4-Aminopyridine; D007770:L-Lactate Dehydrogenase; D003402:Creatine Kinase