Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Pivot Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Target Concepts:
Gene/Protein
Disease
Symptom
Drug
Enzyme
Compound
Query: EC:1.3.5.1 (
succinate dehydrogenase
)
8,177
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
We studied the coordinated regulation of myosin heavy chains (MHC) and metabolic enzymes within individual overloaded adult rat plantaris fibers. This was done using monoclonal antibodies raised against distinct developmental and adult MHCs, and quantitative microphotometric
succinate dehydrogenase
(
SDH
) and glycerol-3-phosphate dehydrogenase (GPDH) enzyme assays. Overload shifted MHC expression in the order IIb-->IIx-->IIa-->alpha/I, with a tripling of cells coexpressing I and
alpha-MHC
, and a transient reexpression of two embryonic MHC and the neonatal isoform in preexisting myofibers. Overload caused a rapid, size-independent, 50% decrease in GPDH activity across all cell types, which recovered by 6 wk. Fiber
SDH
activities varied according to MHC composition, such that overloaded fibers coexpressing IIa MHC displayed control slow fiber
SDH
levels, whereas cells expressing IIx and IIb MHC displayed a transient 30% increase in
SDH
that recovered by 6 wk. Our results suggest that during overload, fibers adapt progressively to the new functional requirements and display more efficient cellular energy utilization and delivery characteristics. The time course of adaptations suggests a role for glycolytic enzymes in the initiation of these transformations.
...
PMID:Coordinated expression of myosin heavy chain isoforms and metabolic enzymes within overloaded rat muscle fibers. 927 35
Cardiac muscle adaptation is essential for maintaining physical capacity after ascending to high altitude. This study examines the effects of high altitude training on myocardial metabolic enzyme activity and composition of
alpha-myosin heavy chain
(MHC). Rats were randomly divided into normobaric sedentary (NS) and training (NT) groups, and hypobaric sedentary (HS) and training (HT) groups. HS and HT rats were exposed to hypobaric hypoxia (simulated 4,000-5,000 m) for 5 weeks (24 h/day), and HT rats simultaneously received swim training. Hypoxia exposure for 5 weeks led to a decrease in
succinate dehydrogenase
(
SDH
) and citrate synthase (CS) activities in the left ventricle (LV), and a decrease in CS, hexokinase (HK) and total lactate dehydrogenase (LDH) activities in the right ventricle (RV) (p < 0.05, HS vs. NS). Furthermore, 1 h/day swim training during hypoxia exposure enhanced the CS activity in LV and the
SDH
and CS activities in RV (p < 0.05, HT vs. HS). The percentages of
alpha-MHC
in both ventricles in HT were higher than those in HS (p < 0.05). We conclude that exercise training at high altitude is beneficial for cardiac muscle adaptation to hypoxia by increasing activities of enzymes and percentage of
alpha-MHC
. This may contribute to improved cardiac function and work capacity at high altitude.
...
PMID:Hypoxic training increases metabolic enzyme activity and composition of alpha-myosin heavy chain isoform in rat ventricular myocardium. 1975 6
