Myofibrillar ATPase activity in human muscle fast-twitch subtypes.
Under local anesthesia, a muscle biopsy was removed from an individual with a high percentage of type II subtypes. The muscle sample was assayed for myofibrillar ATPase activity using various acid preincubation pH values. Subtle differences were found to exist in the acid-lability of ATPase activity among the type II fibers. These observations suggest different ratios of IIA/IIB myosis and may reflect a gradual transformation between type IIA and IIB fibers.
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D006801:Humans; D009119:Muscle Contraction; D009132:Muscles / Q000201:enzymology*; D009210:Myofibrils / Q000201:enzymology*
D000251:Adenosine Triphosphatases