Objective To investigate the effect of nalmefene on the cerebral ischemia-reperfusion (I/R) injury in rats.Methods Forty-eight male Sprague-Dawley rats, aged 3-4 months, weighing 220260 g, were randomly allocated to control group (group C), sham operation group (group S), cerebral I/R group (group I/R), or nalmefene group (group N) using a random number table, with 12 rats in each group.Cerebral I/R was induced by occlusion of bilateral common carotid arteries for 20 min followed by reperfusion.Group C received no treatment.Group S underwent 20 min exposure of bilateral common carotid arteries and then received suture.In group N, nalmefene 0.1 mg/kg was injected intraperitoneally immediately after reperfusion.At 6, 24 and 72 h of reperfusion, venous blood samples were collected for determination of the concentrations of S-100β protein and neuron-specific enolase (NSE) in plasma by enzyme-linked immunosorbent assay.After the last blood sampling, the rats were sacrificed, and brains were removed for determination of interleukin-1beta (IL-1β) and tumor necrosis factor-alpha (TNF-α) contents in brain tissues by enzyme-linked immunosorbent assay.Results Compared with group C, the plasma S-100β protein and NSE concentrations at each time point of reperfusion, and TNF-α and IL-1βcontents in brain tissues were significantly increased in S and I/R groups (P＜0.01).Compared with group S, the plasma S-100β protein and NSE concentrations at each time point of reperfusion, and TNF-α and IL-1β contents in brain tissues were significantly increased in group I/R (P＜0.01).Compared with group I/R, the plasma S-100β protein and NSE concentrations at each time point of reperfusion, and TNF-α and IL-1β contents in brain tissues were significantly decreased in group N (P ＜ 0.01).Conclusion Nalmefene can mitigate cerebral I/R injury in rats.

Objective To evaluate the effect of ulinastatin on brain injury induced by lipopolysaccharide (LPS) in mice.Methods Ninety adult male C57 mice,aged 3-4 months,weighing 200-300 g,were randomly divided into 3 groups (n =30 each) using a random number table:control group (C group),LPS group and ulinastatin group (U group).Group U received intraperitoneal injection of ulinastatin 10 000 U/kg,while group L received the equal volume of normal saline,and 10 min later brain injury was produced with LPS 1 μg/g injected into the cerebral ventricle.Ten animals were chosen and blood samples were taken for determination of plasma concentrations of S100β protein and neuron-specific enolase (NSE) at 1,3 and 7 days after LPS injection.Then the animals were sacrificed and hippocampal tissues were obtained for determination of interleukin-1β (IL-1 β) and tumor necrosis factor-α (TNF-α) contents and IL-1β mRNA and TNF-α mRNA expression.Results Compared with C group,the plasma concentrations of S100β protein and NSE and contents of IL-1β and TNF-α were significantly increased at 1,3 and 7 days after LPS injection,and IL-1β mRNA and TNF-α mRNA expression was up-regulated at 1 and 3 days after LPS injection in LPS and U groups.Compared with group LPS,the plasma concentrations of S100β protein and NSE and contents of IL-1β and TNF-α were significantly increased,and IL-1β mRNA and TNF-α mRNA expression was down-regulated at 1 and 3 days after LPS injection in group U.Conclusion Ulinastatin can attenuate brain injury induced by LPS in mice,and the mechanism is related to inhibited inflammatory responses.

Objective To evaluate the effect of deferoxamine on learning and memory ability in aged rats.Methods Forty-two healthy male Sprague-Dawley rats,aged 18 months,weighing 450-550 g,were randomly divided into 2 groups (n =21 each) using a random number table:normal saline group (group N) and deferoxamine group (group D).In group D,deferoxamine 150 mg/kg was injected intraperitoneally once a day for 6 consecutive days,while the equal volume of normal saline was given instead in group N.Morris water maze test was conducted at 2 h after each injection on that day,lasting for 6 days.The escape latency,swimming speed,time of staying at the original platform quadrant and time spent in the central region were recorded.Hippocampal ferritin expression was detected by Western blot before the first administration and at 2 h after 3rd and 2nd administration.Results Compared with group N,the escape latency was significantly shortened,and the percentage of the time of staying at the original platform quadrant and time spent in the central region was increased,the expression of hippocampal ferritin was down-regulated,and no significant change was found in the swimming speed in group D.Conclusion Deferoxamine can enhance the learning and memory ability in aged rats,and reduced iron deposition in hippocampi is involved in the mechanism.

Objective To evaluate the effect of intraperitoneal desferroxmine on the postoperative cognitive function of aged rats.Methods Twenty-four male Sprague-Dawley rats,aged 15-18 months,weighing 490-550 g,were randomly divided into 3 groups (n =8 each) using a random number table:control group (group C),operation group (group O),and desferroxmine group (group D).Exploratory laparotomy was performed after anesthesia in O and D groups.In group D,desferroxmine was injected intraperitoneally (100 mg/kg per time,each time lasting for 12 h) for 7 consecutive days,starting from 7 days before operation,while the equal volume of normal saline (100 ml/kg) was given in group O.All the rats underwent Morris water maze test at 3 days after operation,and the escape latency and frequency of crossing the original platform were recorded.The rats were then sacrificed and the hippocampus was removed for detection of ferritin expression.Results Compared with group C,the escape latency was significantly prolonged,the frequency of crossing the original platform was decreased,and ferritin expression was up-regulated in group O,and no significant changes were found in each parameter mentioned above in group D.Compared with group O,the escape latency was significantly shortened,the frequency of crossing the original platform was increased,and ferritin expression was down-regulated in group D.Conclusion Intraperitoneal desferroxmine 100 mg/kg (injected for 7 consecutive days) before operation can improve the postoperative cognitive function of aged rats.

Objective To evaluate the effect of surgical trauma on the cognitive function and expression of hepcidin and ferroportin 1 (FP1) in hippocampus in aged rats.Methods One hundred male Sprague-Dawley rats,aged 18 months,weighing 400-500 g,were randomly divided into 2 groups with 50 rats in each group:control group (group C) and surgical trauma group (group ST).The rats were anesthetized with chloral hydrate,but underwent no operation in group C.The rats Were anesthetized with chloral hydrate and underwent 30 min of modified exploratory laparotomy in group ST.Ten rats were chosen from each group at 24 h after operation and the cognitive function was assessed using Morris water-maze test for 6 consecutive days.Ten rats were sacrificed on 1st,3rd,5th and 7th days after beginning of Morris water-maze test and brains were removed for determination of hepcidin and FP1 expression in hippocampus by PCR and Western blot.Results Compared with group C,the escape latency was significantly prolonged,the time of staying at the original platform quadrant and frequency of crossing the original platform were decreased on 3rd,4th and 5th days after beginning of Morris water-maze test,and the expression of hepcidin was up-regulated and the expression of FP1 was down-regulated at each time point in group ST (P ＜ 0.05).Conclusion Surgical trauma can decrease the cognitive function in aged rats and the mechanism may be related to up-regulation of hepcidin expression and down-regulation of FP1 expression in hippocampus.

Objective To investigate the effect of surgical trauma on the cognitive function and activation of microglias in hippocampus in rats of different ages.Methods Seventy-two male Sprague-Dawley rats,aged 3-4months,were randomly allocated into 2 groups:adult control group (n =30) and adult surgery group (n =42).Seventy-two male Sprague-Dawley rats,aged 18-20 months,were randomly allocated into 2 groups:aged control group (n =30) and aged surgery group (n =42).The rats were anesthetized with 5% chloral hydrate 4-6 ml/kg and underwent exploratory laparotomy in surgery groups,while normal saline 1 ml/kg was injected intraperitoneally in control groups.Morris water maze test was performed at 1-7 days after surgery.Fear conditioning test was performed 1 day after surgery to evaluate the space and fear memory abilities.The animals were sacrificed on 1st,3rd and 7th days after surgery and hippocampi were removed for measurement of OX42 expression in microglias by immunohistochemistry.Results Compared with adult control group,the percentage of freezing time in total time was significantly decreased,and OX42 expression in microglias was up-regulated on 1st day after surgery (P ＜ 0.05),and no significant change was found in the escape latency and the number of crossing the original platform in adult surgery group (P ＞ 0.05).Compared with aged control group,the escape latency was significantly prolonged,the number of crossing the original platform was decreased,the percentage of freezing time in total time was decreased,and OX42 expression in microglias was up-regulated on 1st and 3rd days after surgery in aged surgery group (P ＜0.05).Conclusion Surgical trauma decreases fear memory ability,but exerts no effect on the space memory ability in adult rats.Surgical trauma decreases the space and fear memory abilities in aged rats,which maybe related to activation of microglias in hippocampus.

Objective To investigate the effect of dexamethasone on the postoperative cognitive function in rats.Methods One hundred and eighty Sprague-Dawley rats,aged 18-20 months,weighing 400-600 g,were randomly allocated into 3 groups (n =60 each)∶ control group (C group),surgery group (S group) and dexamethasone group (D group).In groups S and D,the rats were anesthetized with 5％ chloral hydrate 4-6 ml/kg and underwent abdominal surgery.The rats in group D received intraperitoneal injection of dexamethasone 10 mg/kg at the beginning of anesthesia,while the rats in group C underwent no surgery and received intraperitoneal injection of normal saline 1 ml/kg instead.Six rats in each group were chosen at 3 h and 7 days after surgery and sacrificed,and their brains were immediately removed for detection of the expression of OX42 (a specific marker for activation of microglia) in hippocampus.Another 6 rats in each group were chosen at 3 h,and 1,3 and 7 days after surgery and sacrificed,and their brains were immediately removed for detection of the expression of IL-1β mRNA and TNF-α mRNA in hippocampus.Cognitive function was assessed by Morris water maze test and fear conditioning test.Results Compared with group C,the escape latency was prolonged,the frequency of crossing the original platform was decreased,the postoperative freezing time was shortened,and the expression of OX42 after surgery and IL-1β mRNA and TNF-α mRNA at 3 h and 1 and 3 days after surgery was up-regulated in groups S and D (P ＜ 0.05 or 0.01).Compared with group S,the escape latency was shortened,the frequency of crossing the original platform was increased,the postoperative freezing time was prolonged,and the expression of OX42 at 3 h after surgery and IL-1β mRNA and TNF-α mRNA at 3 h and 1 and 3 days after surgery was down-regulated in group D (P ＜ 0.05 or 0.01).Conclusion Dexamethasone can inhibit the over-activation of microglia and reduce the inflammatory response,thus improving cognitive function in rats.

AIM: To study the effects of tumor necrosis factor-α (TNF-α) on the transcriptional activity of nuclear factor-erythroid 2-related factor 2 (Nrf2) in pulmonary microvascular endothelial cells. METHODS: Rat pulmonary micro-vascular endothelial cells (PMVECs) were cultured by lung tissue block pasted methods, and identified immunocytochemically using Ⅷ factor-related antigen. The cells were treated with different doses TNF-α (prepared in serum-free medium) for 4 h. Subcellular localization and levels of Nrf2 in PMVECs were observed with immunocytochemical methods. Nuclear extract were obtained to assayed transcriptional activity of Nrf2 with EMSA. Total RNA were isolated to assay the mRNA expression of Nrf2 by RT-PCR. RESULTS: The protein level of Nrf2 in the nuclei and transcriptional activity increased dose-dependently in PMVECs after treated with TNF-α at concentrations of 2.5, 5.0 or 10.0 μg/L. However, the protein level of Nrf2 in nuclei and transcriptional activity decreased dose-dependently in PMVECs after treated with TNF-α at concentrations of 20 or 40 μg/L. No different mRNA expression of Nrf2 in PMVECs treated with TNF-α at all concentration above was observed. CONCLUSION: Transcriptional activity of Nrf2 increases in PMVECs treated with low or moderate doses of TNF-α and decreases in PMVECs treated with high doses of TNF-α.

Objective To investigate the effects of inhalation of different concentrations of isoflurane on the expression of cytochrome c ( Cyt c) in hippocampus in aged rats.Methods Sixty-three aged male SD rats (20 months) weighing 500-600 g were randomly divided into 3 groups(n=21each):control group inhaling 30%O2 for 2h (group C) and 2 isoflurane groups anesthetized with 0.75 % and 1.5 % isoflurane in 30 % O2 for 2 h respectively (group Ⅰ1 and Ⅰ2 ).Arterial blood samples were obtained from 5 rats at 30 min, 1 and 2 h of anesthesia for blood gas analysis. Eight animals were killed at 24 h after anesthesia in each group.Their hippocampi were immediately removed for determination of Gyt c expression by immuno-histochemistry and Western blot analysis.Cognitive function was assessed by Morris water maze test the day before experiment and once a day for 6 consecutive days starting from the 1st postoperative day.Results The Cyt c expression in hippocampus was significantly increased in Ⅰ1 and Ⅰ2 groups in a concentration-dependent manner as compared with group C.The escape latency was significantly prolonged and the frequency of crossing the original platform and the duration of staying at the original platform quadrant were decreased in group Ⅰ1 and Ⅰ2 compared with group C.Conclusion Inhalation of isoflurane anesthesia can decrease cognitive function through up-regulating the Gyt c expression in hippocampus in aged rats.

Objective To investigate the effects of isoflurane on receptor for advanced glycation endproducts (R(A)GE) expression in the hippocampus in rats. Methods Forty-five male 4-month-old and 45 male 24-month-old rats were used in this study. The animals were divided into 2 age groups ( n = 45 each): the aged group (group O) and the adult group (group A). Each group was further divided into 3 subgroups ( n = 15 each):Ⅰ control subgroup (group OC,AC) inhaled 30% O2 in air; 1 single isoflurane inhalation subgroup (group OS,AS) inhaled 1.5 % isoflurane for 2 h and Ⅲ repeated isoflurane inhalation subgroup (group OR, AR) inhaled 1.5 % isoflurane 2 h per day for 3 days. One day after isoflurane inhalation, learning and memory function was assessed using Morris water maze test in 8 animals in each subgroup. The rest of each subgroup were killed and their hippocampi were immediately isolataed for detection of RAGE mRNA and protein expression by RT-PCR and immuno-histochemistry. Results The cognitive function was impaired after signle or repeataed isoflurane anesthesia as compared with control animals in both aged and adult groups. The expression of RACE mRNA and protein in hippocampus was significantly increased after either single or repeated isoflurane anesthesia in aged group but only after repeated isoflurane anesthesia in adult gpoup. There was no significant difference in RAGE mRNA and protein expression in the hippocampus between control and single isoflurane inhalation animals in adult group. Conclusion Isoflurane can reduce learning and memory function in both aged and adult rats by increasing RAGE expression in hippocampus especially in aged rats.