Neuroprotective effect of urinary trypsin inhibitor against focal cerebral ischemia-reperfusion injury in rats.
BACKGROUND
Acute inflammatory reactions cause neuronal damage in cerebral ischemia-reperfusion. Urinary trypsin inhibitor (UTI), a serine protease inhibitor, is cytoprotective against ischemia-reperfusion injury in the liver, intestine, kidney, heart, and lung through its antiinflammatory activity. Neuroprotective action of UTI on transient global cerebral ischemia has been documented. This is the first study to determine whether UTI is neuroprotective against transient focal cerebral ischemia.


METHODS
Adult male Wistar rats were randomly assigned to the following treatment groups: 0.9% saline (control, n = 9); 100,000 U/kg UTI (n = 9); and 300,000 U/kg UTI (n = 9). Treatments were performed intravenously 10 min before right middle cerebral artery occlusion for 2 h and subsequent reperfusion. Ninety-six hours after the onset of reperfusion, the motor neurologic deficit and the cerebral infarct size were evaluated. Furthermore, immunohistochemical staining for myeloperoxidase and nitrotyrosine to count infiltrating neutrophils and nitrated cells, respectively, was performed on the brain sections.


RESULTS
Infarct volume in the 300,000 U/kg UTI group was smaller than in the 100,000 U/kg UTI and saline control groups (P < 0.05). Treatment with 300,000 U/kg UTI showed a trend to improve neurologic outcome but did not reach statistical significance (P = 0.0693). The significant decrease in neutrophil infiltration was observed in the ischemic hemisphere treated with 300,000 U/kg UTI compared with saline control (P < 0.05). Nitrotyrosine deposition in the ischemic hemisphere was significantly reduced in the 300,000 U/kg UTI group compared with saline control and 100,000 U/kg UTI groups (P < 0.05).


CONCLUSIONS
Intravenous pretreatment with 300,000 U/kg UTI reduces focal ischemia-reperfusion injury in the rat brain, potentially opening a novel therapeutic avenue for the treatment of cerebral ischemia.
Yano
Toshiyuki
T
Department of Anesthesiology, Kumamoto University School of Medicine, Japan. tymac@kaiju.medic.kumamoto-u.ac.jp
Anraku
Sakiko
S
Nakayama
Ryosuke
R
Ushijima
Kazuo
K
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001921:Brain / Q000473:pathology; D002452:Cell Count; D002560:Cerebrovascular Circulation / Q000187:drug effects; D006023:Glycoproteins / Q000494:pharmacology* / Q000627:therapeutic use; D020925:Hypoxia-Ischemia, Brain / Q000473:pathology / Q000517:prevention & control*; D007150:Immunohistochemistry; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology / Q000517:prevention & control; D017078:Laser-Doppler Flowmetry; D008297:Male; D009422:Nervous System Diseases / Q000503:physiopathology / Q000517:prevention & control; D018696:Neuroprotective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D009504:Neutrophils / Q000187:drug effects / Q000378:metabolism; D009195:Peroxidase / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D015427:Reperfusion Injury / Q000473:pathology / Q000517:prevention & control*; D014361:Trypsin Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use*; D014443:Tyrosine / Q000031:analogs & derivatives*
D006023:Glycoproteins; D018696:Neuroprotective Agents; D014361:Trypsin Inhibitors; C002744:3-nitrotyrosine; D014443:Tyrosine; D009195:Peroxidase; C028665:urinastatin