Microbiopsies of @entity1 skeletal muscle are increasingly adopted by physiologists for a variety of experimental assays given the reduced invasiveness of this procedure compared to the classic Bergstrom percutaneous biopsy technique. However, a recent report demonstrated lower mitochondrial respiration in @entity3857 -permeabilized muscle fiber bundles (PmFB) prepared from microbiopsies vs. Bergstrom biopsies. We hypothesized that @entity857 -induced contraction (rigor) of smaller length microbiopsy PmFB causes a greater reduction in maximal respiration vs. Bergstrom, such that respiration could be increased by a @entity3999 II ATPase-inhibitor ( @entity12602 ; @entity57802 ). Eleven males and females each received a 2 mm diameter percutaneous microbiopsy and a 5 mm diameter Bergstrom percutaneous biopsy in opposite legs. @entity3264 / @entity5910 (5/0.5 mM)-supported respiration in microbiopsy PmFB was lower than Bergstrom at submaximal concentrations of @entity857 . 5  M @entity57802 reduced this impairment such that there were no differences relative to Bergstrom    @entity57802 . Surprisingly, @entity2388 (5 mM)-supported respiration was not different between either biopsy technique   @entity57802 , whereas @entity57802 increased @entity4588 -supported respiration in Bergstrom only. @entity5568 emission was lower in microbiopsy PmFB compared to Bergstrom PmFB in the presence of @entity57802 . Microbiopsies contained fewer type I fibers (37 vs. 47%) and more type IIX fibers (20 vs. 8%) compared to Bergstrom possibly due to sampling site depth and/or longitudinal location. These findings suggest that smaller diameter percutaneous biopsies yield lower @entity3264 -supported mitochondrial respiratory kinetics which is increased by preventing @entity857 -induced rigor with @entity3999 inhibition. Microbiopsies of @entity1 skeletal muscle can be utilized for assessing mitochondrial respiratory kinetics in PmFB when assay conditions are supplemented with @entity57802 , but fiber type differences with this method should be considered.

Mitochondrial Bioenergetics and Fiber Type Assessments in Microbiopsy vs. Bergstrom Percutaneous Sampling of XXXX Skeletal Muscle.

@entity1 :: ('9606', 'Species') :: ['human'] @entity5568 :: ('D006861', 'Chemical') :: ['H2O2'] @entity57802 :: ('CHEBI:63235', 'Chemical') :: ['BLEB'] @entity3264 :: ('D018698', 'Chemical') :: ['glutamate', 'Glutamate'] @entity4588 :: ('MESH:D019802', 'Chemical') :: ['succinate'] @entity3857 :: ('MESH:D012503', 'Chemical') :: ['saponin'] @entity12602 :: ('MESH:C472645', 'Chemical') :: ['Blebbistatin'] @entity5910 :: ('MESH:C030298', 'Chemical') :: ['malate'] @entity3999 :: ('79784', 'Gene') :: ['myosin'] @entity857 :: ('MESH:D000244', 'Chemical') :: ['ADP'] @entity2388 :: ('MESH:D019289', 'Chemical') :: ['pyruvate']
@entity1 :: (9606,Species) :: ['Human']
