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Skeletal muscle maximal mitochondrial activity in ambulatory children with cerebral palsy
Author(s) -
Dayanidhi Sudarshan,
Buckner Elisa H,
Redmond Robin S,
Chambers Henry G,
Schenk Simon,
Lieber Richard L
Publication year - 2021
Publication title -
developmental medicine and child neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.658
H-Index - 143
eISSN - 1469-8749
pISSN - 0012-1622
DOI - 10.1111/dmcn.14785
Subject(s) - ambulatory , citrate synthase , skeletal muscle , respiratory chain , mitochondrion , medicine , mitochondrial dna , mitochondrial respiratory chain , electron transport chain , coenzyme q – cytochrome c reductase , chemistry , endocrinology , enzyme , gene , biochemistry , cytochrome c
Aim To compare skeletal muscle mitochondrial enzyme activity and mitochondrial content between independently ambulatory children with cerebral palsy (CP) and typically developing children. Method Gracilis biopsies were obtained from 12 children during surgery ( n =6/group, children with CP: one female, five males, mean age 13y 4mo, SD 5y 1mo, 4y 1mo–17y 10mo; typically developing children: three females, three males, mean age 16y 5mo, SD 1y 4mo, 14y 6mo–18y 2mo). Spectrophotometric enzymatic assays were used to evaluate the activity of mitochondrial electron transport chain complexes. Mitochondrial content was evaluated using citrate synthase assay, mitochondrial DNA copy number, and immunoblots for specific respiratory chain proteins. Results Maximal enzyme activity was significantly (50–80%) lower in children with CP versus typically developing children, for complex I (11nmol/min/mg protein, standard error of the mean [SEM] 1.7 vs 20.7nmol/min/mg protein, SEM 4), complex II (6.9nmol/min/mg protein, SEM 1.2 vs 21nmol/min/mg protein, SEM 2.7), complex III (31.9nmol/min/mg protein, SEM 7.4 vs 72.7nmol/min/mg protein, SEM 7.2), and complex I+III (7.4nmol/min/mg protein, SEM 2.5 vs 31.8nmol/min/mg protein, SEM 9.3). Decreased electron transport chain activity was not the result of lower mitochondrial content. Interpretation Skeletal muscle mitochondrial electron transport chain enzymatic activity but not mitochondrial content is reduced in independently ambulatory children with CP. Decreased mitochondrial oxidative capacity might explain reported increased energetics of movement and fatigue in ambulatory children with CP.What this paper adds Skeletal muscle mitochondrial electron transport chain enzymatic activity is reduced in independently ambulatory children with cerebral palsy (CP). Mitochondrial content appears to be similar between children with CP and typically developing children.