Human urinary kallidinogenase can promote the establishment of collateral circulation in the ischemic penumbra due to the stenosis or occlusion of middle cerebral artery and then increase the perfusion.

Patients with acute ischemic stroke will be given human urinary kallidinogenase .Then we will estimate the cerebral collateral circulation in ischemic regions and final infarct volume, comparing with traditional therapy such as Shuxuening injection, which will provide new evidence for the treatment of ischemic stroke. Perfusion Weighted Imaging(PWI) could be a method to reflect the infarction center and low perfusion of tissue.

Inclusion Criteria:

• Age:greater than or equal to 18 years old and less than or equal to 70 years old;
• Time of onset is less than 7 days;
• Acute cerebral infarction due to the stenosis or occlusion of middle cerebral artery diagnosed by CT or MRI;
• The National Institute of Health Stroke Scale(NIHSS) score is 4 to 20;
• Excluding intracranial hemorrhage using CT or MRI.

Exclusion Criteria:

• The NIHSS score is less than or equal to 3;
• Patients with cerebral aneurysm, cerebral hemorrhage, brain tumor, brain contusion and laceration of brain and other diseases;
• Intracranial hemorrhage displaying by CT or MRI; Cardiac insufficiency;
• Cardiac insufficiency;
• Chronic liver disease(A/G inversion),elevated alanine aminotransferase(ALT)(more than 1.5 times the normal value);
• Increased serum creatinine(more than 1.5 times the normal value);
• Poorly controlled diabetes;
• Recently suffered from hemorrhagic disease or bleeding tendency;
• Recent use of angiotensin-converting enzyme inhibitor (ACEI) drugs;
• Allergic constitution and had a variety of drug allergy history;
• Women in period of pregnancy or lactation.