Fingertip Synchrotron Radiation Angiography for Prediction of Diabetic Microangiopathy

Abstract

Diabetic microangiopathy causes acetylcholine-induced paradoxical vasoconstriction in arterioles (20-200 μm). Because conventional angiographic systems lack sufficient spatial resolution (100-200 μm), they are not useful for prediction of diabetic microangiopathy and for the prevention of lethal cardiovascular diseases.

To determine whether fingertip synchrotron radiation microangiography has enough spatial resolution to quantitate arteriolar diameter changes, and whether an arteriolar paradoxical vasoconstriction is a characteristic observation for diabetic microangiopathy, diameter reduction as arteriolar branching and difference of the diameter changes induced by acetylcholine between control (n = 5) and diabetic rats (n = 5) were analyzed.

Fingertip synchrotron radiation microangiography visual-ized the arterioles with a diameter range of 30-300?m and demonstrated vascular diameter reduction as branching with a fixed ratio (r = 0.93, P < 0.004, y = 0.81x + 0.004 and r = 0.73, P < 0.001, y = 0.39x + 23.3; with x and y representing diameters of mother, and 1st and 2nd daughter segments). A vasodilatory reaction was induced by acetylcholine in the control (142.4 ± 61.9 to 190.9 ± 73.5, P < 0.05, n = 25), and, in contrast, para-doxical vasoconstriction in diabetic rats (201.6 ± 83.0 to 16 0.4 ± 67.9, P < 0.05, n = 37).

In conclusion, the fingertip synchrotron radiation microangiography predicted diabetic microangiopathy and warrants further investigations into its usefulness to prevent lethal cardiovascular disease.