Nevertheless, there were some limitations in this study.
Firstly, the model of STZ-induced diabetes would rather
represent the type 1 diabetes, although the majority of
diabetic patients are type 2. Thus, the model may not be
appropriate for study of type 2 diabetes in which the insulin
resistance is a major feature. However, the STZ-induced
diabetic rat model can cause hyperglycemia, oxidative
stress, and vascular dysfunctions resembled those found in
the clinical diabetes. The study model is therefore useful
for the evaluation of compounds that are able to prevent
diabetic associated vascular dysfunctions. Secondly, we
evaluated the vascular reactivity by monitoring the changes
in arterial pressure which is influenced by both vascular
and cardiac functions; thus, the effect on cardiac function
could not be excluded