Stroke/Cerebral Vasospasm

Cerebral microvasculature as a target for stroke therapeutics (Kevin),

This is a nice study that demonstrates the importance of microvascular protection during reperfusion following an ischemic event. It is interesting that I study the opposite end of things, the large cerebral arteries that are responsible for establishing an appropriate vascular resistance that protect the microvasculature during changing perfusion pressures. I have found that middle cerebral arteries that have been ischemic for 2 hours and reperfused for 24 hours lost their intrinsic tone and myogenic reactivity. This suggests that cerebrovascular resistance and autoregulation of blood flow is impaired. This would put tremendous pressure on the microcirculation, that likely contributes to edema and possibly hemorrhagic transformation during reperfusion. I am curious as to the time course for all these events. In your model, does the hyperemia correspond to when edema formation is likely or would is be during delayed hypoperfusion? Also, what size arteries are you measuring? I was under the impression that the microcirculation did not have a contractile component. Do these vessels have intrinsic tone as well? I commend you on your study and model that provides both functional and structural insights into the microvascular component of stroke.

Tue Dec 8