Comparison of cerebral and cutaneous microvascular dysfunction with the development of type 1 diabetes.

Diabetes can lead to cerebral and cutaneous vascular dysfunction. However, it is still unclear how vascular function changes with the development of diabetes and what differences exist between cerebral and cutaneous vascular dysfunction. Thus, it is very important to monitor changes in cerebral and cutaneous vascular function responses and study their differences during diabetes development. With the assistance of newly developed skull and skin optical clearing techniques, we monitored the responses of sodium nitroprusside (SNP)- and acetyl choline (ACh)-induced cerebral and cutaneous vascular blood flow and blood oxygen in diabetic mice during the development of type 1 diabetes (T1D) by combining laser speckle contrast imaging with hyperspectral imaging. We then compared the differences between cerebral and cutaneous vascular responses and explored the reasons for abnormal changes induced in response to different vascular beds. In the early stage of diabetes (T1D-1 week), there were abnormal changes in the cerebral vascular blood flow and blood oxygen responses to SNP and ACh as well as cutaneous vascular blood oxygen. The cutaneous vascular blood flow response also became abnormal from T1D-3 weeks. Additionally, the T1D-induced abnormal blood flow response was associated with changes in vascular myosin light chain phosphorylation and muscarinic acetylcholine receptor M3 levels, and the aberrant blood oxygen response was related to an increase in glycated hemoglobin levels. These results suggest that the abnormal cutaneous vascular blood oxygen response occurred earlier than the blood flow response and therefore has the potential to serve as a good assessment indicator for revealing cerebrovascular dysfunction in the early stage of diabetes.