Figure 7.

Effects of asymmetric dimethylarginine (ADMA) infusion and dimethylarginine dimethylaminohydrolase (DDAH)-1 overexpression on ischemia/reperfusion (IR)-induced peritubular capillary loss. (a) The upper panel shows the representative microphotographs of CD31-positive capillaries. (b) The lower panel shows the quantitative data. Magnification × 400. Staining for CD31 was performed on frozen kidney sections to evaluate endothelial injury and capillary rarefaction. Control kidneys demonstrated a very homogenous staining pattern. IR-injured kidneys demonstrated the absence of CD31 staining in many areas. ADMA infusion further reduced the CD31 staining, which was prevented in DDAH-1 transgenic (DDAH-1 Tg) mice. Rarefaction of CD31-positive capillaries was assessed semiquantitatively using a score from 0 to 4. A higher score, therefore, reflects a higher degree of capillary loss.