Effect Of Urinary Kallikrein On Cerebral Blood Flow,Angiogenesis And Inflammation In A Photothrombotic Mice Model

Objective: To investigate the effect of delayed administration of Urinary Kallikrein on cerebral blood flow, angiogenesis and inflammation in a photothrombotic mice model.Methods: Fourty male C57/BL6 mice were subjected to photothrombotic surgery and randomly divided into two groups: Urinary Kallikrein group(n=20) and control group(n=20). Images of cerebral blood flow and Sr CBF of ischemic area were obtained by Laser speckle imaging on the 3th day, 7th day respectively. Medication or normal saline were given twice a day through intraperitoneal injection for 3 consecutive days starting on the 4th day after surgery. All mice were sacrificed on the 7th day. Immunofluorescence was used to detect vessel density,angiogenesis and microglia activation and proliferation. Infarction volume was measured through Nissl's staining. Neurologic function was assessed by m NSS and Corner test on the 1st, 3rd, 5th and 7th day respectively.Results: There was no difference in the Sr CBF of ischemic area between the two groups on the 3rd day. However, Sr CBF of ischemic area was higher in the Urinary Kallikrein group on the 7th day(P<0.05). Compared with control group, treatment with Urinary Kallikrein markedly increased the vessel density and the number of Brdu/vw F and Brdu/laminin double positive cells in the peri-infarct region(all P<0.05). However, Iba-1 positive cells and Brdu/Iba-1 double positive cells were significantly lower in Urinary Kallikrein group(all P<0.01). Last but not the least, we didn't observe an obvious distinction in infarct volume and neurologic function between the two groups(all P>0.05).Conclusions: Delayed administration of Urinary Kallikrein could improve the cerebral blood flow,inhibit inflammation and promote angiogenesis in a photothrombotic mice model.