Hotta K, Shimotsu R, Behnke BJ, Masamoto K, Yagishita K, Poole DC, Kano Y. Effect of Diabetes on Microvascular Morphology and Permeability of Rat Skeletal Muscle: In Vivo Imaging Using Two-Photon Laser Scanning Microscopy. J Appl Physiol (1985). 2024 Aug 15. doi: 10.1152/japplphysiol.00222.2024. Epub ahead of print. PMID: 39143906.
骨格筋毛細血管は連続型に分類され、本来物質が簡単に漏出することはありません。しかしながら、Hotta, et al. J Appl Physiol 2018 では運動誘発性筋損傷は骨格筋毛細血管における血管透過性の亢進を認めた。本研究ではストレプトゾシン誘発性の１型糖尿病モデルラットを対象に、筋損傷のない正常な骨格筋の血管透過性を２光子レーザー操作型顕微鏡 Two-photon laser scanning microscopy を用いてリアルタイムで検証しました。その結果、筋損傷はないものの、血管透過性の亢進を認めました。また、透過型電子顕微鏡を用いて内皮細胞の超微細構造を観察した結果、内皮細胞の肥厚、細胞間隙の数の増加、細胞内小胞のサイズの増加などが観察された。これらの糖尿病に伴う内皮細胞の形態変化は、血管透過性の一因かもしれない。また、より萎縮している筋ほど、血管透過性が高いことも明らかとなりました。
本研究は、電気通信大学、カンザス州立大学、東京医科歯科大学との共同研究です。
Skeletal muscle capillaries are classified as continuous type, and substances do not leak easily. However, Hotta, et al (J Appl Physiol 2018) found that exercise-induced muscle damage increased vascular permeability in skeletal muscle capillaries. In this study, we used a two-photon laser scanning microscopy to examine the vascular permeability of normal skeletal muscles without muscle damage in streptozocin-induced type 1 diabetes model rats. As a result, we found that although there was no muscle damage, vascular permeability was increased. In addition, we observed the ultrastructure of endothelial cells using a transmission electron microscope, and found that endothelial cell thickening, an increase in the number of intercellular clefts, and an increase in the size of intracellular vesicles were observed. These morphological changes in endothelial cells associated with diabetes may be a factor in vascular permeability. It was also revealed that the more atrophied the muscle, the higher the vascular permeability.
This study is a collaborative study with the University of Electro-Communications, Kansas State University, and Tokyo Medical and Dental University.
Comments