Hyperbaric oxygen exposure improves blood glucose level and muscle oxidative capacity in rats with type 2 diabetes.
BACKGROUND
The effects of exposure to hyperbaric oxygen on blood glucose level and muscle oxidative capacity in rats with type 2 diabetes were investigated.


METHODS
Five-week-old male Goto-Kakizaki rats were divided into four groups: normobaric (NN; exposed to 21% oxygen at 760 mm Hg for 8 weeks), hyperbaric to normobaric (HN; exposed to 36% oxygen at 950 mm Hg for 4 weeks, followed by 21% oxygen at 760 mm Hg for 4 weeks), normobaric to hyperbaric (NH; exposed to 21% oxygen at 760 mm Hg for 4 weeks, followed by 36% oxygen at 950 mm Hg for 4 weeks), and hyperbaric (HH; exposed to 36% oxygen at 950 mm Hg for 8 weeks).


RESULTS
Blood glucose levels were lower in the HN, NH, and HH groups than in the NN group. Up-regulated mRNA expression levels of peroxisome proliferator-activated receptor-gamma co-activator-1alpha were observed in the soleus muscles of the HN, NH, and HH groups and in the plantaris muscles of the HN and HH groups. The soleus muscles of the NN group contained only type I fibers, whereas those of the HN, NH, and HH groups contained type I, type IIA, and type IIC fibers. An increased percentage of type I fibers and a decreased percentage of type IIB fibers were observed in the plantaris muscles of the NH, HN, and HH groups.


CONCLUSIONS
Exposure to hyperbaric oxygen reduces high blood glucose levels and improves oxidative capacities in the skeletal muscles of rats with diabetes, and these effects are maintained under normobaric conditions even after exposure to hyperbaric oxygen.
Gu
Ning
N
Laboratory of Neurochemistry, Graduate School of Human and Environmental Studies, Kyoto University, Kyoto 606-8501, Japan.
Nagatomo
Fumiko
F
Fujino
Hidemi
H
Takeda
Isao
I
Tsuda
Kinsuke
K
Ishihara
Akihiko
A
D000818:Animals; D001786:Blood Glucose / Q000032:analysis / Q000378:metabolism*; D001835:Body Weight / Q000502:physiology; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000378:metabolism*; D004435:Eating / Q000502:physiology; D006651:Histocytochemistry; D006931:Hyperbaric Oxygenation / Q000379:methods*; D007328:Insulin / Q000097:blood*; D008297:Male; D018485:Muscle Fibers, Skeletal / Q000378:metabolism*; D009929:Organ Size / Q000502:physiology; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
D001786:Blood Glucose; D007328:Insulin; D000071248:Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; C501429:Ppargc1a protein, rat; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D014157:Transcription Factors