Microvascular permeability of rat cerebral pia mater by using image computer analysis

Microcirculation viviperception and fluorescent tracer techniques were used and digital image analysis applied for quantitative measurement of fluorescein sodium (FiNa) permeability in microvessels of the cerebral pia mater. The diffusion permeation equations of FiNa within the blood vessels and through the vessel walls into the perivascular tissue of normal rats and ischemic rats were established with two vessels as study object, thus the permeation speed equations under different ischemic conditions were deduced. Based on analysis of the results, we deduced the relation between the permeability and the intersection angle of two vessels. Result: Logarithm model showed a good fit of the experiment data. The permeation equation showed logarithmic distribution and then tended towards stability. FiNa could pass through microvessel walls with the highest speed in the one-hour ischemic rat group, and the permeation speed of FiNa in rats receiving reperfusion after twelve hours of ischemia was much faster than that in normal rats. Conclusion: The method can be useful for quantitative analysis of cerebral pia mater microvascular permeability.