BACKGROUND: The mechanism of intracerebral hemorrhage (ICH)-induced hemorrhagic brain injury is very complicated, involving the position-occupying effect of cephalophyma, ischemic factors, the toxic effect of hematoma components, the destruction of blood-brain barrier, etc. The expression and effect of hemeoxygenase-1 (HO-1) in the cerebrovascular disease has been paid close attention. OBJECTIVE: To observe the expression of HO-1 and change of superoxide dismutase (SOD) in the peri-hematomal brain tissue of rats following ICH. DESIGN: Randomized controlled animal experiment. SETTING: Department of Neurology, Yijishan Hospital Affiliated to Wannan Medical College. MATERIALS: Forty healthy male SD rats, of clean grade, weighing from 250 to 300 g, were provided by Qinglongshan Animal Farm of Nanjing. The involved 40 rats were randomized into sham-operation group (n =5) and ICH group (n =35), and ICH group was divided into 7 subgroups with 5 rats in each: ICH 6, 12, 24, 48, 72, 100 and 168 hours groups. Rabbit anti-rat HO-1 immunohistochemial kit ( Boster Co., Ltd., Wuhan) and SOD kit (Jiancheng Bioengineering Institute, Nanjing)were used in this experiment. METHODS: This experiment was carried out in the Department of Neurology, Yijishan Hospital Affiliated to Wannan Medical College Between April and July 2005. In the ICH group: Autologous blood of rats was injected into the head of caudate nucleus to create ICH animal models. In the sham-operation group, the same amount of normal saline was injected into the head of caudate nucleus of rats. The brains of rats in each group were harvested at different time points. The hematoma-side brain tissue was cut open in the coronal plane taking hematomal region as center, and the posterior part was fixed with 100 g/L neutral formaldehyde. 100 mg brain tissue was taken from anterior part. The number of positive cells in HO-1 and SOD activity in peri-hematomal brain tissue at different time after ICH were detected by immunohistochemical method and xanthine oxidation method respectively. MAIN OUTCOME MEASURES: ① The expression of HO-1 in the peri-hematomal brain tissue of rats in two groups following ICH.② The expression of SOD activity in the peri-hematomal brain tissue of rats in two groups following ICH. RESULTS: ①The number of HO-1 positive cells in the peri-hematomal brain tissue of rats in two groups following ICH 6, 12, 24, 48, 72, 120 and 168 hours was (11.03±2.01),(16.47±2.98),(25.50±5.65),(51.57±7.05),(47.33±4.73),(26.57±5.12),(7.63±2.17) cells/high-fold visual field , respectively; The number of HO-1 positive cells in the ICH 12-120 hours groups was significantly higher than that of sham-operation group [(6.07±1.85)cells/high-fold visual field, P < 0.01]; The HO-1 positive cells were the most in the ICH 48 hours group and were still expressed a little in the ICH 168 hours group. ② The SOD in the brain tissue of rats at ICH 6, 12, 24, 48, 72, 120 and 168 hours was (404.46±8.14),(396.84±10.97),(387.74±5.32),(356.21±9.27),(307.95±10.15),(357.48±11.28) and (402.98±7.23) kNU/g, respectively; The SOD activity of ICH 12 to 120 hours groups was significantly lower than that of sham-operation group [(415.47±11.44) kNU/g,P < 0.01], and that of ICH 72 hours group was the lowest. There was no significant difference of SOD activity between ICH 168 hours group and sham-operation group (P > 0.05). CONCLUSION: Following ICH, the expression of HO-1 in peri-hematomal brain tissue of rats in two groups is obviously increased, but the antioxidant ability of brain tissue is decreased. The changes of both maybe play an important role in the formation of ICH-induced hemorrhagic brain injury. BACKGROUND: The mechanism of intracerebral hemorrhage (ICH) -induced hemorrhagic brain injury is very complicated, involving the position-occupying effect of cephalophyma, ischemic factors, the toxic effect of hematoma components, the destruction of blood-brain barrier, etc. The expression OBJECTIVE: To observe the expression of HO-1 and change of superoxide dismutase (SOD) in the peri-hematomal brain tissue of rats following ICH SET: Department of Neurology, Yijishan Hospital Affiliated to Wannan Medical College. MATERIALS: Forty healthy male SD rats, of clean grade, weighing from 250 to 300 g, were provided by Qinglongshan Animal Farm of Nanjing. The involved 40 rats were randomized into sham-operation group (n = 5) and ICH group (n = 35), and ICH group was divided into 7 subgroups with 5 rats in each: ICH 6, 12, 24, 48, 100 and 168 hours groups. Rabbit anti-rat HO-1 immunohistochemial kit (Boster Co., Ltd., Wuhan) and SOD kit (Jiancheng Bioengineering Institute, Nanjing) were used in this experiment. METHODS: This experiment was carried out in the Department of Neurology , Yijishan Hospital Affiliated to Wannan Medical College Between April and July 2005. In the ICH group: Autologous blood of rats was injected into the head of caudate nucleus to create ICH animal models. In the sham-operation group, the same amount of normal saline was injected into the head of caudate nucleus of rats. The brains of rats in each group were harvested at different time points. The hematoma-side brain tissue was cut open in the coronal plane taking the hematogenous region as center, and the posterior part was fixed with 100 g / L neutral formaldehyde. 100 mg brain tissue was taken from anterior part. The number of positive cells in HO-1 and SOD activity in peri-hematomal brain tissue at different times after ICH were detected by immunohistochyMAIN OUTCOME MEASURES: ① The expression of HO-1 in the peri-hematomal brain tissue of rats in two groups following ICH. ② The expression of SOD activity in the peri-hematoma brain tissue of rats in two groups following ICH. RESULTS: ① The number of HO-1 positive cells in the peri-hematoma brain tissue of rats in two groups following ICH 6, 12, 24, 48, 72, 120 and 168 hours was (11.03 ± 2.01) (16.47 ± 2.98), (25.50 ± 5.65), (51.57 ± 7.05), (47.33 ± 4.73), (26.57 ± 5.12), (7.63 ± 2.17) cells / 1 positive cells in the ICH 12-120 hours groups was significantly higher than that of the sham-operation group [(6.07 ± 1.85) cells / high-fold visual field, P <0.01]; The HO- the ICH 48 hours group and were still a little in the ICH 168 hours group. ② The SOD in the brain tissue of rats at ICH 6, 12, 24, 48, 72, 120 and 168 hours was (404.46 ± 8.14), (396.84 ± 10.97), (387.74 ± 5.32), (356.21 ± 9.27), (307.95 ± 10.15), (357.48 ± 11.28) and (402.98 ± 7.23) kNU / g, respectively; The SOD activity of ICH 12 to 120 hours groups was Significant lower than that of sham-operation group [(415.47 ± 11.44) kNU / g, P <0.01], and that of ICH 72 hours group was the lowest. There was no significant difference of SOD activity between ICH 168 hours group and sham -operation group (P> 0.05). CONCLUSION: Following ICH, the expression of HO-1 in peri-hematomal brain tissue of rats in two groups is obviously increased, but the antioxidant ability of brain tissue is decreased. The changes of both maybe play an important role in the formation of ICH-induced hemorrhagic brain injury.