title: The effect of aging on anaerobic and aerobic enzyme activities in human skeletal muscle.
abstract: The effect of aging on metabolic enzyme activity remains controversial, possibly due to physical activity differences. We examined the effect of aging on the enzyme activity for anaerobic and aerobic pathways in nonweight-bearing human skeletal muscle from relatively sedentary males. The muscle obliquus internus abdominis was analyzed for anaerobic (creatine kinase, adenylate kinase, and lactate dehydrogenase) and aerobic (2-oxoglutarate dehydrogenase and carnitine palmitoyltransferase) enzyme activities in two groups: middle-aged (29-54 years) and older (61-74 years) adults. All enzyme activities were lower in older versus middle-aged adults when results were expressed as muscle wet weight (p <.05). When activity was expressed relative to the protein content, only lactate dehydrogenase remained significantly lower in older versus middle-aged adults (p <.001). In conclusion, some of the reduction in muscle performance in older adults may be due to lower activity of the anaerobic and aerobic enzymes as well as protein content, not solely due to a decrease in physical activity.
authors.affiliation: Department of Biochemistry, J. Sniadecki Academy of Physical Education and Sport, Gdansk, Poland. kaczorj@mcmaster.ca
authors.forename: Jan J
authors.initials: JJ
authors.lastname: Kaczor
authors.forename: Wieslaw
authors.initials: W
authors.lastname: Ziolkowski
authors.forename: Jedrzej
authors.initials: J
authors.lastname: Antosiewicz
authors.forename: Stanislaw
authors.initials: S
authors.lastname: Hac
authors.forename: Mark A
authors.initials: MA
authors.lastname: Tarnopolsky
authors.forename: Jerzy
authors.initials: J
authors.lastname: Popinigis
mesh_terms: D000009:Abdominal Muscles / Q000201:enzymology*; D000263:Adenylate Kinase / Q000378:metabolism*; D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism*; D002334:Carnitine O-Palmitoyltransferase / Q000378:metabolism*; D003402:Creatine Kinase / Q000378:metabolism*; D006801:Humans; D007655:Ketoglutarate Dehydrogenase Complex / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D008019:Life Style; D008297:Male; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology
chemical_list: D007770:L-Lactate Dehydrogenase; D007655:Ketoglutarate Dehydrogenase Complex; D002334:Carnitine O-Palmitoyltransferase; D003402:Creatine Kinase; D000263:Adenylate Kinase