Maturation of mitochondrial and other isoenzymes of creatine kinase in skeletal muscle of preterm born infants.
We studied pre- and postnatal changes in total creatine kinase (CK) activity, mitochondrial creatine kinase (Mi-CK) activity and immunochemical reactivity with anti-Mi-CK antibodies in skeletal muscle specimens from 12 infants, 10 of them preterm born, after a pregnancy varying between 28 and 40 weeks. Our results demonstrate that Mi-CK is present in fetal human quadriceps muscle and that the specific activity of Mi-CK increases during prenatal development from week 28 to 40 by a factor about two. Generally, adult levels have not been reached at birth, indicating a further postnatal increase of the activity of the enzyme. The Mi-CK protein content also increases during prenatal development. These results suggest that in human skeletal muscle the expression and accumulation of Mi-CK starts at mid-gestation, later than is known to occur for cytosolic CK.
Smeitink
J
J
Institute of Paediatrics, University Hospital Nijmegen, The Netherlands.
Ruitenbeek
W
W
van Lith
T
T
Sengers
R
R
Trijbels
F
F
Wevers
R
R
Sperl
W
W
de Graaf
R
R
D002950:Citrate (si)-Synthase / Q000032:analysis; D003402:Creatine Kinase / Q000032:analysis*; D003576:Electron Transport Complex IV / Q000032:analysis; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000378:metabolism*; D007527:Isoenzymes; D008297:Male; D008931:Mitochondria, Muscle / Q000201:enzymology*
D007527:Isoenzymes; D003576:Electron Transport Complex IV; D002950:Citrate (si)-Synthase; D003402:Creatine Kinase