OBJECTIVE To determine the role of endogenous carbon monoxide(CO) in oxidant-mediated organ injury following limb ischemia-reperfusion (I/R) in rats. METHODS: Sixty-four SD rats were divided into 4 groups: Sham group, Sham + zinc protoporphyrin (ZnPP, an inhibitor of heme oxygenase activity), 2-hour ischemia followed by 4-hour reperfusion (I/R) group and I/R + ZnPP group. Carboxyhemoglobin (COHb) level in the artery blood, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in the lung, heart, liver and kidney were detected. The 24-hour survival rate of rats was studied. RESULTS: Compared with the sham group, the COHb level and MDA content significantly increased, while the SOD activity and the survival rate significantly decreased in I/R group (P lt; 0.05). Compared with the I/R group, MDA content significantly increased, while the SOD activity, the 24-hour survival rate and COHb level significantly decreased in I/R + ZnPP group (P lt; 0.05, respectively). CONCLUSION: Limb I/R could lead to the oxidant-mediated multiple organ injury accompanied by the increase of CO level which play an important role in the defense against I/R-induced remote multiple organ injury in rats.
OBJECTIVE: To investigate a animal model of spinal cord injury in different degrees of impact. METHODS: A new weight-drop device was designed with the character of controlled degree of impact and time. After thirty-five rats underwent different degrees of impact, their motor function and pathological changes were observed. RESULTS: In control group, the rats could walk after reviving, and the micro-structure of spinal cord was normal. With 0.5 mm depth of impact, the rats also could walk, and the micro-structure of spinal cord did not change obviously. With 0.8 mm depth of impact, the rats could walk after several days of injury and only slight damage could be found in spinal cord. When the impact depth increased to 1.0 or 1.5 mm, the rats were paralyzed completely and could not walk after four weeks of injury. Severe injury was observed in spinal cord. CONCLUSION: This animal model of spinal cord injury is based on different degrees of impact. It has stable and repetitive characters for the research on spinal cord injury.
Objective To investigate the quantity and distribution of motor fiber of rat’s C7 nerve root. Methods Motor fiber quantity and section area in the main nerves of the upper extremity and the fascicles of C7 in 30 SD rats were analyzed.Results Fascicles and certain amount (207) of motor fibers from the anterior division of C7 were distributed to musculocutaneous nerve and median nerve, the orientation of these fibers were not clear. The ones (323) from posterior division were to the axillary, radial, and dorsal thoracic nerves, thus the orientation of these fascicles was relatively definite. Conclusion Thedistribution of the motor fibers and fascicles in the divisions of C7 in rat is similar to human beings, so rat is a relatively good model for the study of selective C7 nerve root transfer.
Objective To investigate the expression and significance of growth-associated protein 43 (GAP-43) in the dorsal root ganglion (DRG) and intervertebral disc in the rat model of intervertebral disc inflammation. Methods A total of 103 adult male Sprague Dawley rats (weighing, 200-250 g) were randomly divided into the experimental group (n=48), the control group (n=48), and the blank control group (n=7). Fluoro-gold (F-G) as tracer was injected into the L5, 6 intervertebral disc of 3 groups; after 7 days of F-G injection, complete Freund’s adjuvant (50 µL) and the same volume of saline were injected in the experimental group (to prepare the model of intervertebral disc inflammation) and the control group, respectively, and the blank control group had no further treatment. After 1, 3, 7, and 14 days, T13-L6 DRG and L5, 6 intervertebral disc of experimental group and control group were harvested to detect the GAP-43 by using fluorescent immunohistochemistry, in situ hybridization, and RT-PCR. The DRG and intervertebral disc of blank control group were also harvested after 8 days of F-G injection. Results Fluorescent immunohistochemistry results showed that the number of F-G-labeled GAP-43 immunoreaction (GAP-43-IR) cells of the DRGs in the experimental group was significantly higher than that in the control group (P lt; 0.05) at 3 days, and no significant difference was found at the other time points (P gt; 0.05). There was no significant difference in the cross-sectional area of F-G-labeled GAP-43-IR cells between the experimental group and the control group at each time point (P gt; 0.05). The co-expression of GAP-43 with calcitonin gene-related peptide (CGRP) and isolectin B4 (IB4)-binding glycoprotein exhibited that the expression of CGRP was 91.4% ± 7.4% in the control group and was 87.6% ± 7.8% in the experimental group, showing no significant difference between 2 groups (P gt; 0.05). There was no IB4-binding glycoprotein expression in GAP-43-IR cells of the DRGs in 2 groups. The expressions of GAP-43, CGRP, and IB4-positive nerve fibers in the intervertebral disc exhibited that the GAP-43-IR nerve fibers in the experimental group were significantly more than that in the control group (P lt; 0.05), but no significant difference was found in the expression of CGRP between 2 groups (P gt; 0.05); and there was no IB4-binding glycoprotein expression in GAP-43-IR nerve fibers of the intervertebral disc in 2 group. In situ hybridization and RT-PCR detection showed that the positive expression cells ratio of GAP-43 mRNA and the level of GAP- 43 mRNA were significantly higher in the experimental group than in the control group at 1 day (P lt; 0.05), and no significant difference was found at the other time points (P gt; 0.05). Conclusion Intradiscal inflammatory environment may induce the expression of GAP-43, and potentially promote the nerve fiber ingrowth of rat.
Objective To investigate the effect of exogenous erythropoietin (EPO) on the denervated muscle atrophy. Methods Twenty-four SD male rats, weighting 200-220 g were made the models of denervated gastrocnemius muscle after sciatic nerves were transected under the piriform muscle at the right lower leg, and were randomly divided into two groups (n=12). rhEPO (2 500 U/kg) was injected daily into the denervated gastrocnemius muscle in EPO group, and normal sal ine was injected into the denervated gastrocnemius muscle in control group. To observe the general state of health of the experimental animal, the muscle wet weight, the muscle cell diameter, the cross section area, the protein amount, thepercentage of the apoptotic muscle cells, and the Na+-K+-ATPase and Ca2+-ATPase activities were measured 2 and 4 weeks after operation. Results All experimental animals were survived during experiment without cut infection, and all animals could walk with pull ing the right knee. At 4 weeks after operation, 7 cases showed ulcer in the right heel, inculding 5 in the control group and 2 in the EPO group. At 2 and 4 weeks after operation, the muscle wet weight in EPO group was (885.59 ± 112.35) and (697.62 ± 94.74) g, respectively; in control group, it was (760.63 ± 109.05) and (458.71 ± 58.76) g, respectively; indicating significant differences between two groups (P lt; 0.01). The protein amount in EPO group was (77.37 ± 5.24) and (66.37 ± 4.87) mg/mL, respectivly；in control group, it was (65.39 ± 4.97) and (54.62 ± 6.32) mg/mL；indicating significant differences between two groups (P lt; 0.01). At 2 and 4 weeks after operation, the myofibrillar shapes were nearly normal in EPO group while there were muscle fiber atrophy, some collapse and obviously hyperblastosis between muscle bundle. There were significant differences in the muscle cell diameter and the cross section between two groups (P lt; 0.01). However, the percentage of the apoptotic muscle cells was 11.80% ± 1.74% and 28.47% ± 1.81% in control group, respectively, which was significantly smaller than that in EPO group (21.48% ± 2.21% and 55.89% ± 2.88%, P lt; 0.01). At 2 and 4 weeks after operation, Na+-K+-ATPaseand Ca2+-ATPase activities in EPO group were higher than those in control group (P lt; 0.01). Conclusion EPO can delay the denervated muscle atrophy.
目的 研究利多卡因对海马的神经毒性是否会对大鼠空间学习记忆能力产生影响，并探讨大鼠空间学习能力的变化与海马CA3区锥体细胞数目的相关性。 方法 将成年Wistar雄性大鼠随机分为基础值组（n=7）和利多卡因惊厥组（n=40）。基础值组大鼠静脉给予生理盐水后使用Y迷宫测定大鼠的空间学习能力。利多卡因惊厥组大鼠尾静脉持续输注利多卡因造成惊厥，待大鼠恢复正常运动以后放入鼠笼重新饲养。并于惊厥后第1、3、5、7天从中随机抓取大鼠测试其空间学习能力以及组织学改变。根据对应天数将利多卡因惊厥组的40只大鼠随机细分为Day-1、Day-3、Day-5、Day-7亚组，每亚组10只。所有大鼠在测定空间学习能力之后立即处死，取出大脑并做石蜡包埋，冠状面切片后进行组织学检测，显微镜下评估海马CA3区锥体细胞状态。 结果 ① 基础值组和Day-1、Day-3、Day-5、Day-7亚组大鼠的Y迷宫穿梭次数分别为（25.2 ± 3.7）、（27.1 ± 8.1）、（36.9 ± 9.9）、（38.7 ± 10.6）、（40.6 ± 16.3）次，除Day-1亚组与基础值组比较差异无统计学意义（P＞0.05）外，其余各亚组与基础值组差异均有统计学意义（P＜0.05）；② 与基础值组单位面积（10.3 ± 4.5）个（异常锥体）细胞比较，利多卡因惊厥组大鼠海马CA3区异常锥体细胞数增加，Day-1、Day-3、Day-5、Day-7亚组计数值分别为13.0 ± 7.2、15.6 ± 5.0、19.6 ± 8.1、18.1 ± 5.1，且与大鼠Y迷宫穿梭次数呈正相关（r=0.711，P＜0.05）。 结论 利多卡因引起的惊厥使成年大鼠海马依赖性空间学习能力下降，利多卡因的神经毒性引起的海马异常锥体细胞增多可能是造成这一现象的一种原因。
Objective To establish a reliable rats model of orthotopic liver transplantation with non-heart beating donors. Methods The model was established with modified double-cuff method. According to obtain pre-liver warm ischemia time experiencing non-heart-beat the rats were divided into 3 groups: 10 min (R10 group), 20 min (R20 group) and 30 min (R30 group), then one week survival after operation was compared in rats. Results The operative time of donor was 30 min approximately except warm ischemia time and the cold preservation time of donor liver was 1 h. The anastomotic time for suprahepatic vena cava was 12-22 min (mean 15 min). The anastomotic time for portal vein and infrahepatic vena cava was about 2 min and 1 min, respectively. The anhepatic phase sustained 14-24 min (mean 19 min). The operative time of receptor was 50-65 min (mean 60 min). Twelve rats died at 24 h after operation, which was considered as operative failure. The success rates of operation in R10 group, R20 group, and R30 group were 95% (19/20), 80% (16/20), and 65% (13/20), respectively. After one week the survival rate was 95% (18/19), 81% (13/16), and 54% (7/13), respectively. Conclusions Improved non-heart donor liver transplantation model of rat on the basis of Kamada’s “twocuff technique” acts as a good simulation in clinical non-heart-donor liver transplantation. This study showes that rat liver can tolerate warm ischemia time less than 30 min, the short-term survival after transplantation can reach satisfactory results. However, long-term survival requires further study.
Objective To investigate the rule of the morphological changes of the detrusor muscle and its neuromuscular junction after the medullary cone injury in rats. Methods Forty-eight SDadult rats were divided into 6 groups randomly, each of which was 8. There werenormal control group(group A), 4 weeks group(group B), 6 weeks group(group C), 8 weeks group(group D), 10 weeks group(group E) and 12 weeks group(group F) after the medullary cone injury respectively. The medullary cone injury was completed in the level of L4,5 with a sharp and transsectional way. The HE dyeing of the detrusor muscle was performed firstly to observe the changes of the section areas of muscle fibers. And the electron microscopic samples of the detrusor muscle were made to investigate the rules of the ultrastructructral changes in the detrusor muscle and its neuromuscular junction. Finally, the Masson trichromatic dyeing of the detrusor muscles was performed to calculate the percentages of the smooth muscle and the connective tissue.Results The HE dyeing of the detrusor muscle indicated the section areas of muscle fibers in groups E, F was significantly less than that in group A (P＜0.05). The gradually aggravated ultrastructructral changes of detrusor cells in groups B-F were observed in atonic bladders，such as various shape and size，malalignment, wide separation between musclecells, abundant collagen fibrils and irregular dense structures between individual cells, obvious rough endoplasmic reticulum widen and mitochondrial edema were noted．And the ultrastructructral changes of the neuromuscular junctions manifested that the similar structures in group A and the reduction of the mitochondria and synaptic vesicles was seen in groups B, C and D, the conspicuous degenerative neuromuscular junction and the obvious reduction of the synaptic vesiclesand the mitochondria was observed in group E,and the deteriorative degenerativeneuromuscular junction and the obvious reduction or disappearance of the synaptic vesicles and the mitochondria even to the degenerative corpuscle was noted in group F. The Masson trichromatic dyeing in the detrusor muscles indicated that there were significant differences in the percentage of the connective tissue in the detrusor muscles between groups E,F and group A, and between group E and group F respectively (P＜0.05). Conclusion The irreversible changes of the detrusor muscle and its neuromuscular junction canbe seen in the 10th week after medullary cone injury in rat. And the nerverepairing procedures should be performed before this.