Abstract
We hypothesize that it is critical factor for controlling red blood cell velocity (VRBC) in longitudinal capillary running parallel to muscle fiber whether intercapillary anastomoses are non-functional, i.e. no flow of red blood cells, or functional capillaries. We examined the role of capillary network, especially, a number of anastomoses and its lumen diameter on VRBC in atrophied rat muscle with 2-wk hindlimb suspension using a pencil-lens intravital microscopy and a confocal laser scanning microscope (CLSM). VRBC in capillary and anastomosis of soleus was significantly increased by atrophy, while VRBC in capillary and anastomosis of gastrocnemius was not significantly changed. CLSM images demonstrated lumen diameter of anastomoses in atrophied gastrocnemius was not changed rather increased in spite of significant reduction of lumen diameter of longitudinal capillaries, suggesting the anastomoses are functional capillaries. The lumen diameter of longitudinal capillaries and anastomoses in atrophied soleus was significantly decreased, suggesting the anastomoses are non-functional capillaries. The present results suggest that intercapillary anastomoses seem to affect VRBC due to plasma skimming. [Jpn J Physiol 55 Suppl:S104 (2005)]
