Determination of fiber types of chicken skeletal muscles based on reaction for actomyosin, calcium+2, magnesium+2-dependent adenosine triphosphatase.
Muscle fiber subtypes, determined with the actomyosin Ca+2,Mg+2-adenosine triphosphatase (ATPase) reaction in chicken anterior latissimus dorsi and posterior latissimus dorsi muscles, were demonstrated only after acid or alkaline preincubation followed by a 60-min enzyme incubation. In contrast, subtypes were demonstrated in the sartorius muscle either with or without preincubation. A single-step procedure was therefore possible with this muscle. The results were generally similar to those obtained previously with the mycosin Ca+2-ATPase procedure. Both methods revealed corresponding muscle fiber subtypes, with the exceptions noted below. The actomyosin Ca+2,Mg+2-ATPase procedure, following preincubation at pH 9.4 and 10.3, resulted in a similar reaction intensity in all fiber types. With the myosin Ca+2-ATPase procedure, the IRA (slow) type in anterior latissimus dorsi and sartorius muscles and the I (slow), IIR (fast oxidative-glycolytic), and IIW (fast glycolytic) types in posterior latissimus dorsi muscle had a higher reaction intensity following preincubation at pH 9.4 than at pH 10.3. Fiber Types IIR and IIW in sartorius muscle were easily distinguished with the actomyosin Ca+2,Mg+2-ATPase procedure.
Sosnicki
A
A
Muscle Biology Laboratory, University of Wisconsin, Madison 53706.
Cassens
R G
RG
D000205:Actomyosin / Q000032:analysis*; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase / Q000032:analysis*; D000252:Calcium-Transporting ATPases / Q000032:analysis*; D002645:Chickens / Q000033:anatomy & histology*; D006651:Histocytochemistry; D009132:Muscles / Q000032:analysis*
D000205:Actomyosin; D017301:Ca(2+) Mg(2+)-ATPase; D000252:Calcium-Transporting ATPases