TY - JOUR
T1 - Comparison of capillary architecture between slow and fast muscles in rats using a confocal laser scanning microscope
AU - Murakami, Shinichiro
AU - Fujinoc, Hidemi
AU - Takeda, Isao
AU - Momota, Ryusuke
AU - Kumagishi, Kanae
AU - Ohtsuka, Aiji
PY - 2010
Y1 - 2010
N2 - The skeletal muscle is classified into 2 types, slow oxidative or fast glycolytic muscle. For further characterization, we investigated the capillary architecture in slow and fast muscles. The rat soleus and extensor digitorum longus (EDL) muscles were used as representatives of slow and fast muscles, respectively. To investigate capillary density, sections of both types of muscle were stained with alkaline phosphatase; the soleus muscle showed more intense reactivity, indicating that it had a denser capillary structure than the EDL muscle. We then injected fluorescent contrast medium into samples of both muscle types for light and confocal-laser microscopic evaluation. The capillary density and capillary-to-fiber ratio were significantly higher, and the course of the capillaries was more tortuous, in the soleus muscle than in the EDL muscle. Capillary coursed more tortuously in the soleus than in the EDL muscle. Succinate dehydrogenase (SDH) activity, an indicator of mitochondrial oxidative capacity, and vascular endothelial growth factor (VEGF) expression were also significantly higher in the soleus muscle. Thus, we conclude that slow oxidative muscle possess a rich capillary structure to provide demanded oxygen, and VEGF might be involved in the formation and/or maintenance of this highly capillarized architecture.
AB - The skeletal muscle is classified into 2 types, slow oxidative or fast glycolytic muscle. For further characterization, we investigated the capillary architecture in slow and fast muscles. The rat soleus and extensor digitorum longus (EDL) muscles were used as representatives of slow and fast muscles, respectively. To investigate capillary density, sections of both types of muscle were stained with alkaline phosphatase; the soleus muscle showed more intense reactivity, indicating that it had a denser capillary structure than the EDL muscle. We then injected fluorescent contrast medium into samples of both muscle types for light and confocal-laser microscopic evaluation. The capillary density and capillary-to-fiber ratio were significantly higher, and the course of the capillaries was more tortuous, in the soleus muscle than in the EDL muscle. Capillary coursed more tortuously in the soleus than in the EDL muscle. Succinate dehydrogenase (SDH) activity, an indicator of mitochondrial oxidative capacity, and vascular endothelial growth factor (VEGF) expression were also significantly higher in the soleus muscle. Thus, we conclude that slow oxidative muscle possess a rich capillary structure to provide demanded oxygen, and VEGF might be involved in the formation and/or maintenance of this highly capillarized architecture.
KW - Capillaly
KW - Skeletal muscle
KW - Succinate dehydrogenase activity
KW - Vascular endothelial growth factor
UR - http://www.scopus.com/inward/record.url?scp=77952788857&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=77952788857&partnerID=8YFLogxK
M3 - Article
C2 - 20200579
AN - SCOPUS:77952788857
VL - 64
SP - 11
EP - 18
JO - Acta Medica Okayama
JF - Acta Medica Okayama
SN - 0386-300X
IS - 1
ER -