The study utilized Power-Doppler Ultrasonic (PD-US) imaging to assess peripheral muscle perfusion dynamics in both male and female mice under Type II diabetic and non-diabetic conditions, considering both exercise and sedentary states. The research specifically observed changes following femoral artery ligation, focusing on how these biological conditions affect recovery and perfusion over a four-week period. Key findings indicated that diabetic mice exhibited significantly delayed perfusion recovery compared to non-diabetic counterparts, with diabetic males taking 47% longer and diabetic females 74% longer to return to baseline perfusion levels.
The investigation further examined the impact of endothelial dysfunction in diabetes by measuring flow-mediated dilation (FMD) in conduit vessels and reactive hyperemia (RH) in resistive vessels indices before and after a 5-minute ischemic event induced by a pressure cuff, using PD-US to capture these patterns. The study found that endothelial responses were significantly impaired in diabetic mice, as demonstrated by reduced FMD and RH indices. The decline was more pronounced in RH indices since it is sensitive to metabolic risks such as diabetic conditions. Additionally, it was observed that exercise mitigated the loss of endothelial function caused by diabetes in both sexes.
Overall, the findings emphasize the role of PD-US in enhancing our understanding of diabetes-related vascular complications. PD-US measurements can accurately track site-specific changes in skeletal muscle perfusion related to diabetes over time. This capability addresses the need for techniques that can regularly monitor atherosclerotic changes, which can lead to ischemic vascular problems.