急性脊髓损伤后内皮素-1与Ca2+含量的变化关系的研究

目的通过检测大鼠急性脊髓损伤(Spinalcordinjury,SCI)后伤段脊髓组织内皮素-1(Endothelin-1,ET-1)含量和Ca2 含量的变化,探讨ET-1和Ca2 在继发性脊髓损伤中的作用机制。方法SD雄性大鼠80只,用改良Allen’s打击法,致伤力为50g/cm,造成C6～7段脊髓中度损伤模型后,用放射免疫法和原子吸收光谱分析法测定SCI后2、4、8、24、72h、1周和2周脊髓组织中ET-1和Ca2 的含量。结果损伤节段脊髓组织ET-1和Ca2 含量均随病程而改变,伤后4h达最高峰,并分别持续至48h和72h,于1～2周仍维持较高水平,与正常值有显著性差异。结论SCI后早期伤段脊髓内ET-1和Ca2 含量增高,参与了脊髓继发性损伤,为临床上ET-1受体拮抗剂与Ca2 拮抗剂联合使用来减轻SCI后继发性损伤提供理论依据。     

外源性供氧对脊髓损伤后继发性脊髓水肿的影响

目的　观察外源性供氧对脊髓损伤组织学的影响。方法　采用Allen法于兔L2 椎体水平造成急性脊髓损伤。对照组不予治疗 ,携氧复合液治疗组和复合液治疗组兔分别在伤后 30min开始给药。于伤后 48h、3、7d、4周分别从各组中取 5只兔 ,进行脊髓组织含水量、丙二醛(MDA)及形态学观察。结果　伤后 48h、3、7d携氧复合液组伤段脊髓组织含水量分别为 (69.1 4±0 .92 ) %、(71 .93± 0 .87) %、(71 .63± 1 .0 1 ) % ;脊髓组织MDA含量分别为 (2 8.54± 5 .98) μmol/g、(2 7.81± 3 .64) μmol/g、(2 6.1 4± 4 .2 6) μmol/g,均显著低于对照组 (P <0 .0 1 )。组织形态学检查携氧复合液组的病理改变较对照组轻。结论　脊髓损伤后早期外源性供氧对继发性脊髓损伤有保护作用。     

汉防己甲素对大鼠急性脊髓损伤的作用及意义

目的：探讨汉防己甲素（Tet）对急性脊髓损伤（ASCI）的保护作用及作用机制。方法：81只大鼠随机分为三组：生盐水对照组（NS组）、汉防己甲素治疗组（Tet组）和甲基强松龙治疗组（MP组），每组27只，用加速型Allen′s打击法制成脊髓急性损伤模型，监测大鼠ASCI后及用药后的血压变化，测定损伤区脊髓Ca^2 、MDA含量；采用氢清除法测定脊髓伤区血流量（SCBF）的变化；连续观测6周ASCI后运动功能评分情况，ASCI后4h,8h、6周取伤区标本进行组织病理检查，结果：ASCI后10s各组动物的MABP显著升高，1min内迅速降至正常水平，之后Tet组舒张压，平均动脉明显降低（P＜0．05），而收缩压降低不明显（P＞0．05）；ASCI后SCBF下降，但Tet组和MP组的SCBF较NS组高（P＜0．05）；损伤区Ca^2 及MDA含量Tet组和MP组均较NS组低，神经功能评分均较NS组高。结论：Tet能改善微循环，防止SCBF的减少；抗脂质过氧化损伤，减少脂质过氧化物MDA的生成；减轻Ca^2 的局部积聚，防止钙超载，阻断继发性损伤的链式反应，减轻组织继发性损伤。对实验性急性脊髓损伤有保护作用。     

尼卡地平控制性降压对家犬脊髓血流的影响

目的　观察尼卡地平控制性降压对家犬脊髓血流的影响。方法　成年杂种犬 6只 ,体重 12 5～ 16kg ,以 2 5 %硫喷妥钠麻醉。股动脉置管监测MAP。以尼卡地平 8μg·kg 1·min 1持续静脉注射控制性降压。以激光多普勒血流仪测定脊髓血流 (SCBF)。结果　降压前MAP为 (12 5 7±10 6 )mmHg ,降压后为 (72 0± 11 2 )mmHg ,平均下降 4 2 8%。降压前SCBF为 (9 80± 1 0 5 )v ,降压后为 (8 0 4± 0 96 )v ,降低幅度为 18%。结论　尼卡地平控制性降压对SCBF影响较小 ,可安全用于脊髓手术。     

大鼠脊髓损伤后线粒体代谢功能和还原型谷胱甘肽水平的变化

目的 探讨大鼠脊髓损伤后伤段脊髓线粒体代谢功能和还原型谷胱甘肽(GSH)水平的变化.方法 取48只SD大鼠,随机分为假手术组(对照组)和脊髓损伤组(SCI组),每组又分为处理后6、12、24 h 3个时相组,每个时相组8只,分别提取伤段脊髓的线粒体,测定线粒体呼吸功能[呼吸Ⅲ态(R3)、呼吸Ⅳ态(R4)、呼吸控制率(RCR)及磷氧比(P/O)值]、三磷酸腺苷酶(ATPase)活性(Na+、K+-ATP酶和Ca2+、Mg2+-ATP酶活性)及GSH的变化.结果 SCI组在伤后6、12、24 h伤段脊髓线粒体的R3、RCR及P/O均显著低于对照组,R4显著高于对照组,差异有统计学意义(P＜0.05).SCl组Na+、K+-ATP酶和Ca2+、Mg2+-ATP酶较对照组明显降低,伤后6 h急剧下降,12 h后稍有代偿性升高,24 h后又下降,与对照组比较差异有统计学意义(P＜0.05).GSH水平SCI组与对照组相比明显降低,以伤后12 h最为明显,差异有统计学意义(P＜0.05).结论 脊髓损伤后伤段脊髓线粒体的呼吸功能、ATPase酶活性及GSH水平明显下降,说明脊髓损伤后线粒体能量代谢功能和自由基清除能力均受到明显损害.     

血小板活化因子及其受体拮抗剂对颈髓损伤后血脊髓屏障病理损害的影响

目的 探讨血小板活化因子(PAF)及其受体拮抗剂对猫颈髓损伤后血脊髓屏障损害的作用。方法 采用鞘内注射PAF及静脉注射PAF受体拮抗剂BN52021，观察其对颈髓损伤后脊髓组织PAF含量、血脊髓屏障的影响。结果 颈髓损伤后颈髓伤区及邻近脊髓组织PAF含量、伊文思蓝含量、水含量均明显增加，鞘内注射PAF可使伤后PAF含量、伊文思蓝含量、水含量增加更为显著。BN52021可抑制伤后颈髓组织PAF含量升高，降低颈髓组织伊文思蓝含量及水含量。结论 PAF是导致颈髓损伤后血脊髓屏障损害的重要因子，而BN52021叫可有效减轻血脊髓屏障的病理损害。     

AMPA谷氨酸受体亚基-2在大鼠脊髓损伤急性期对少突胶质前体细胞凋亡的影响

目的:探讨AMPA谷氨酸受体亚基-2 (AMPA-GluR2)在大鼠脊髓损伤急性期对少突胶质前体细胞(oligodendrocyte precursor cells,OPCs)凋亡的影响。方法:60只SD雌性大鼠随机分为假手术组(Sham组,n=15),脊髓损伤组(SCI组,n=15),AMPA受体拮抗剂NBQX组(n=15)和Ca2+通透性AMPA受体拮抗剂JSTx组(n=15)。SCI组、NBQX组和JSTx组应用Allen′s打击法建立大鼠脊髓(T9)损伤模型。采用BBB评分评估各组大鼠脊髓损伤后运动功能恢复情况。HE染色观察脊髓损伤后病理学改变。免疫组化和免疫蛋白印迹(Western blot)法检测AMPA-GluR2在各组大鼠脊髓组织中的表达情况。免疫荧光标记OPCs并应用TUNEL法检测其在各组中的凋亡情况。结果:SCI组BBB评分较假手术组降低(P0.05),脊髓损伤后3d NBQX组(3.60±0.65)和JSTx组(3.80±0.76)BBB评分较SCI组(1.50±0.35)高(P0.05),NBQX组和JSTx组之间无差异(P0.05)。HE染色结果显示SCI组和两个拮抗剂组的脊髓组织均存在损伤,脊髓组织腹侧和腹外侧白质病理学损伤评分显示NBQX组(1.60±0.42)与JSTx组(1.50±0.35)评分较SCI组(2.30±0.20)低(P0.05)。AMPA-GluR2免疫组化结果显示,脊髓损伤后3d SCI组阳性细胞数(6.15±0.52)较假手术组(13.25±0.21)明显减少(P0.05),NBQX组(2.10±0.42)和JSTx组(4.45±0.54)阳性细胞数较SCI组少(P0.05),NBQX组阳性细胞数最少,与JSTx组比较有显著性差异(P0.05)。Western blot结果显示,脊髓损伤后3d SCI组和两个拮抗剂组AMPA-GluR2表达水平均较假手术组(0.94±0.07)降低(P0.05),NBQX组(0.37±0.07)及JSTx组(0.54±0.12)较SCI组(0.69±0.03)低(P0.05),且NBQX组AMPA-GluR2表达水平最低(P0.05)。免疫荧光显示,脊髓损伤后3d各组大鼠脊髓组织均存在免疫荧光标记的OPCs;TUNEL法检测OPCs凋亡指数表明,NBQX组(0.21±0.02)和JSTx组(0.17±0.01)较SCI组(0.42±0.02)均降低(P0.05),且JSTx组较NBQX组降低(P0.05)。结论:大鼠脊髓损伤急性期OPCs凋亡与脊髓组织中AMPA-GluR2表达下降有关。     

大鼠急性脊髓损伤后白细胞介素-1β表达及其与神经细胞凋亡的关系

目的探讨脊髓损伤(SCI)后白细胞介素(IL)1β表达的变化及其与神经细胞凋亡的关系。方法采用Allen’s法建立大鼠急性SCI模型,用实时定量聚合酶链反应(PCR)和免疫组织化学染色检测SCI后IL1β表达,用原位末端标记法(TUNEL)检测SCI后神经细胞凋亡。结果对照组IL1βmRNA为4.87±0.49,SCI后早期IL1βmRNA明显升高,于伤后6h达高峰为6.95±0.95,两组间差异有统计学意义(P<0.01);免疫组织化学染色也显示伤后6hIL1β染色强度明显增加。TUNEL染色显示,对照组大鼠脊髓组织TUNEL阳性细胞极少(1.82±0.64),伤后6h有少许凋亡细胞出现,24hTUNEL阳性细胞增多最明显(32.38±4.75)。IL1β表达升高与TUNEL阳性细胞增多有明显的关系。结论SCI后IL1β表达升高,它可能参与了诱导神经细胞凋亡。     

实验性脊髓损伤后N—甲基—D—天门冬氨酸受体的变化及其意义

兴奋性氨基酸（ＥＡＡ）已被证明在中枢神经系统的创伤中具有神经毒性作用。为进一步揭示其受体机制，本实验用大鼠脊髓突触质膜作受体制剂，［＾３Ｈ］ＣＰＰ作标记配基，建立体外Ｎ－甲基－Ｄ－天门冬氨酸（ＮＭＤＡ）受体分析的方法，并以Ａｌｌｅｎ脊髓损伤模型分析了脊髓损伤后ＮＭＤＡ受体的改变。结果表明脊髓ＮＭＤＡ受体亲和力（Ｋｄ）为３．５１±０．２６ｎＭ，最大结合数量为６６２．８２±４７．５９ｆｍｏｌ／ｍｇ蛋白     

内皮素-1对大鼠睾丸间质细胞睾酮分泌影响的可能作用机理

目的 :了解内皮素 1(ET 1)影响大鼠睾丸离体间质细胞睾酮分泌的可能作用机理 ,为男性不育症治疗提供一定的理论基础。　方法 :采用大鼠睾丸间质细胞体外孵育技术以及12 5I 睾酮放射免疫法 ,观察ET 1对间质细胞睾酮分泌的影响及其可能作用机理。　结果 :内皮素受体A(ETA)、内皮素受体B(ETB)受体拮抗剂均可逆转ET 1对大鼠离体间质细胞睾酮分泌的抑制作用 ,但Ca2 +通道阻滞剂维拉帕米 (VER)未表现此作用。　结论 :ET 1通过与ETA及ETB结合而发挥作用。其Ca2 +的动员可能不是细胞外Ca2 +进入细胞内。     

大鼠脊髓损伤后一氧化氮合酶基因表达的变化

目的　探讨大鼠脊髓损伤后3种类型一氧化氮合酶（NOS）mRNA表达的变化规律。方法　成年SD大鼠36只,随机分为种类6组,每组6只大鼠。建立大鼠脊髓压迫伤模型,以逆转录-聚合酶链反应（RT-PCR）法测定伤段脊髓组织神经型（nNOS）、诱导型（iNOS）及内皮型（eNOS）一氧化氮合酶的mRNA表达情况。结果　脊髓压迫伤后nNOSmRNA及NOSRNA表达增强,伤后6h达到高峰0.633±0.012、1.236±0.207;iNOSmRNA表达亦增高,但在伤后24h才达到高峰1.043±0.049。结论　脊髓损伤后NOSmRNA的表达增强,但不同类型的NOSmRNA变化规律不同,增强或抑制不同NOSmRNA的表达可能减轻脊髓继发性损伤。     

Uptake and elimination of methylprednisolone from contused cat spinal cord following intravenous injection of the sodium succinate ester

The uptake and elimination of methylprednisolone by the injured cat lumbar spinal cord were examined following a single 30-mg/kg intravenous bolus injection of the sodium succinate ester. The findings were considerably different from those previously reported for normal lumbar cord. When the glucocorticoid was administered 30 minutes after a 400 gm-cm contusion injury, peak tissue concentrations in both injured and uninjured segments of traumatized spinal cord were not achieved until 30 minutes following drug administration. The elimination of methylprednisolone from injured spinal cord tissue was biphasic in nature, with a rapid elimination phase occurring between 1 and 2 hours after drug administration. This rapid elimination phase was followed by a slower phase which paralleled the constant elimination rate from uninjured tissue of traumatized cord (approximate half-time = 6 hours). Significantly more methylprednisolone accumulated in the injured segment of traumatized spinal cord than in an uninjured segment adjacent to the injury site. This was only true, however, if the drug was administered at times up to 1 hour after injury. If injected after 1 hour, uptake by the injured segment decreased significantly with time after trauma and was no different from that observed for the uninjured segment in the same animal, which showed no significant variation with time after trauma. The probable basis for these differences and the possible clinical implications of these pharmacokinetic characteristics are discussed.     

Further studies of nimodipine in experimental spinal cord injury in the rat.

Previously in our laboratory, nimodipine was effective in reversing posttraumatic ischemia and promoting electrophysiologic recovery in a rat spinal cord injury (SCI) model. However, these beneficial effects were achieved when nimodipine was combined with adjuvant therapy to reverse posttraumatic hypotension, by either volume expansion or vasopressor therapy. The present experiments determined if nimodipine alone can increase spinal cord blood flow (SCBF) and improve function after SCI. The hydrogen clearance technique was used to measure SCBF, and motor and somatosensory evoked potentials (MEP and SSEP) were used to quantitate electrophysiologic function. SCBF, MEP, and SSEP were recorded before and after a 52 g clip compression injury at the T1 segment and then repeated after a 35 minute infusion of nimodipine. Twenty-five rats were allocated randomly to five equal groups, each of which received 35 minute infusions of one of the following doses of nimodipine: (1) 0 mg/kg, (2) 0.005 mg/kg, (3) 0.01 mg/kg, (4) 0.025 mg/kg, or (5) 0.05 mg/kg. SCBF decreased after injury in all groups, and there was no increase in SCBF after nimodipine infusion in any group. MEP and SSEP were abolished by the injury in all rats, and there was no recovery of the evoked potentials in any group. It is concluded that adjuvant therapy for posttraumatic hypotension may be necessary for nimodipine to improve SCBF and promote recovery of function in the injured spinal cord.     

神经节苷脂有髓损伤的保护作用观察

目的：观察神经节苷脂对损伤脊髓神经组织的保护作用,并初步探讨其作用机制。方法：重度脊髓损伤大鼠随机分为对照组及神经节苷脂治疗组（n=15)。在蛛网膜下腔注射生理盐水20μl或神经节苷脂30μg。观察体重变化局部血流量、凋亡细胞原位标记、神经功能评价和定量组织学分析。结果：局部血流量2组无明显差异,治疗组存活8率、体重、神经功能评分和残余神经组织面积明显高于对照组,而TUNEL阳性细胞数量明显低于对照组。结论：神经节苷脂对损伤脊髓组织有明显保护作用,可能是通过对神经细胞凋亡的阻断来发挥作用的。     

Failure of naloxone to improve spinal cord blood flow and cardiac output after spinal cord injury

It has been reported that the narcotic antagonist, naloxone, can improve spinal cord blood flow (SCBF) and clinical recovery after experimental spinal cord injury produced by the weight-dropping technique. The purpose of the present study was to determine the effect of naloxone on SCBF, cardiac output (CO) and blood flow to other organs following clip compression injury. Rats were anesthetized, paralyzed and ventilated, with mean systemic arterial pressure (MSAP) recorded continuously. After a C-7-T-1 laminectomy and a 1-minute acute compression injury with a 50-g clip at T-1, rats were given injections of radioactive microspheres for measurement of SCBF, CO, and blood flow to other organs. The first determination was made 15 minutes after injury and a second was made after a 1-hour treatment with naloxone. Treated animals each received an intravenous bolus injection of naloxone (10 mg/kg) followed by a 1-hour intravenous infusion (2 mg/kg/hour). Naloxone failed to improve posttraumatic SCBF in the injured spinal cord. In addition, naloxone did not prevent posttraumatic hypotension or the progressive decline in CO seen between 15 and 75 minutes after injury. Thus, this study does not support the previous claims of a beneficial effect of naloxone on posttraumatic SCBF and MSAP.     

Regional Spinal Cord Blood Flow and Energy Metabolism in Rats after Laminectomy and Acute Compression Injury

Many data are available concerning spinal cord blood flow (SCBF) and metabolism on various models and timing after spinal cord injury, however, detailed information on their exact relationship in the same injury model is lacking. This relationship is a crucial factor in the understanding of the pathophysiology of spinal cord trauma. Rats were subjected to lumbar laminectomy or lumbar spinal cord compression trauma. 3 hours later, changes in SCBF were evaluated autoradiographically and changes in ATP, glucose and lactate levels were analyzed using substrate-specific bioluminescence techniques. Measurements were performed at the lesion site (segment L4), adjacent segments (L3 and L5) and at remote thoracic segments (Th8 to Th9). Laminectomy alone did not change SCBF, both in thoracic and lumbar segments. In contrast, ATP levels were significantly reduced and lactate levels were increased at the lesion site and in adjacent lumbar segments at 3 hours after laminectomy, whereas glucose levels were not significantly changed. In animal subjected to additional compression trauma, SCBF was significantly reduced in segments L3, L4 and L5 paralleled by a significant ATP reduction and lactate increase. Glucose levels did not differ significantly from controls 3 hours after compression injury. This metabolic profile was also reflected in the remote thoracic segments. In contrast, SCBF was not reduced in thoracic segments of traumatized animals. The observation that ATP was already significantly reduced and lactate increased in laminectomized segments and in remote thoracic regions after trauma signals that metabolic changes are sensitive indicators to spinal stress. The fact that posttraumatic metabolic profile differs from the pattern of hemodynamic and metabolic changes induced by ischemia, suggests posttraumatic mediators may be involved in the different regulation of the energy producing machinery.     

The effect of nimodipine and dextran on axonal function and blood flow following experimental spinal cord injury

There is evidence that posttraumatic ischemia is important in the pathogenesis of acute spinal cord injury (SCI). In the present study spinal cord blood flow (SCBF), measured by the hydrogen clearance technique, and motor and somatosensory evoked potentials (MEP and SSEP) were recorded to evaluate whether the administration of nimodipine and dextran 40, alone or in combination, could increase posttraumatic SCBF and improve axonal function in the cord after acute SCI. Thirty rats received a 53-gm clip compression injury on the cord at T-1 and were then randomly and blindly allocated to one of six treatment groups (five rats in each). Each group was given an intravenous infusion of one of the following over 1 hour, commencing 1 hour after SCI: placebo and saline; placebo and dextran 40; nimodipine 0.02 mg/kg and saline; nimodipine 0.02 mg/kg and dextran 40; nimodipine 0.05 mg/kg and saline; and nimodipine 0.05 mg/kg and dextran 40. The preinjury physiological parameters, including the SCBF at T-1 (mean +/- standard error of the mean: 56.84 +/- 4.51 ml/100 gm/min), were not significantly different (p greater than 0.05) among the treatment groups. Following SCI, there was a significant decrease in the SCBF at T-1 (24.55 +/- 2.99 ml/100 gm/min; p less than 0.0001) as well as significant changes in the MEP recorded from the spinal cord (MEP-C) (p less than 0.0001), the MEP recorded from the sciatic nerve (MEP-N) (p less than 0.0001), and the SSEP (p less than 0.002). Only the combination of nimodipine 0.02 mg/kg and dextran 40 increased the SCBF at T-1 (43.69 +/- 6.09 ml/100 gm/min; p less than 0.003) and improved the MEP-C (p less than 0.0001), MEP-N (p less than 0.04), and SSEP (p less than 0.002) following SCI. With this combination, the changes in SCBF were significantly related to improvement in axonal function in the motor tracts (p less than 0.0001) and somatosensory tracts (p less than 0.0001) of the cord. This study provides quantitative evidence that an increase in posttraumatic SCBF can significantly improve the function of injured spinal cord axons, and strongly implicates posttraumatic ischemia in the pathogenesis of acute SCI.     

TRH对大鼠脊髓损伤后SCBF和SEP的影响

脊髓损伤（ＳＣＩ）后内源性阿片肽释放，并参与脊髓的继发损伤机制。ＴＲＨ可阻断阿片肽的自主神经效应，而不影响痛觉。本实验探讨大剂量ＴＲＨ（２ｍｇ／ｋｇ／ｈ）治疗对大鼠脊髓打击伤（Ａｌｌｅｎｓ法１０ｇｘ５ｃｍ）后脊髓血流量（ＳＣＢＦ）和脊髓诱发电位（ＳＥＰ）的影响。脊髓损伤后１ｈ，ＳＣＢＦ开始显著下降，持续至伤后２４ｈ，ＳＥＰ峰潜时呈进行性延长趋势；伤后即刻静脉注射ＴＲＨ（２ｍｇ／ｋｇ／ｈ，共５次），可使伤后即刻和２４ｈ的ＳＣＢＦ显著升高，并使伤后ＳＣＢＦ下降时间延迟３ｈ，同时ＳＥＰ峰潜时有不同程度改善。结果表明，ＴＲＨ对受伤脊髓早期有一定的防治作用，并具有一定的后发效应；同时也可促进脊髓的神经传导功能。本文亦对ＴＲＨ治疗ＳＣＩ的病理生物学机制进行了讨论。     

Lactate and pyruvate metabolism in injured cat spinal cord before and after a single large intravenous dose of methylprednisolone

The lactate content and the lactate/pyruvate ratio of the acutely traumatized cat spinal cord have been studied and were found to rise rapidly following a 400 gm-cm injury. Lactate levels rose nearly twofold within 5 minutes after injury, peaked at 2 hours after injury, and remained significantly elevated for at least 8 hours compared to an adjacent uninjured segment of traumatized cord. Pyruvate levels, on the other hand, fell acutely in the injured section of cord during the 1st hour after injury then rose slowly over an 8-hour period. The changes in tissue lactate and pyruvate metabolism in the spinal cord following injury are consistent with a marked injury-induced reduction in blood flow. The elevation in lactate and the fall in pyruvate levels observed at 1 hour after injury were completely prevented by the intravenous administration of a single 30-mg/kg dose of methylprednisolone sodium succinate at 30 minutes after injury. Lower or higher doses of methylprednisolone were far less effective. The effects of the 30-mg/kg dose of methylprednisolone on tissue lactate content were associated with high tissue levels of the glucocorticoid and were short-lived, paralleling the accumulation and elimination pattern of steroid from the injured tissue. The results suggest that, in addition to other reported beneficial actions of large intravenous doses (30 mg/kg) of methylprednisolone on the injured cord, the glucocorticoid may also improve blood flow to the injured segment as has been suggested by others. The use of high glucocorticoid doses, early therapy initiation, and rigorous maintenance dosing is discussed.     

A pharmacological analysis of the pathophysiological mechanisms of posttraumatic spinal cord ischemia

A pharmacological analysis was carried out to determine the possible role of aberrant calcium fluxes, vasoactive arachidonic acid metabolites, and microvascular lipid peroxidation in the development of posttraumatic spinal cord white matter ischemia. Pentobarbital-anesthetized cats were treated intravenously 30 minutes before a 500-gm-cm contusion injury to the lumbar spinal cord with one of the following test drugs: the Ca++ channel antagonists verapamil, diltiazem, or nifedipine; the cyclo-oxygenase inhibitors ibuprofen or meclofenamate; the thromboxane A2 (TXA2) synthetase inhibitor furegrelate sodium; or the stable epoprostenol (prostacyclin, or PGI2) analogue ciprostene calcium alone or in combination with furegrelate sodium. Another group of animals was pretreated for 5 days before spinal injury with a combination of the antioxidants vitamin E and selenium in high doses. The hydrogen clearance technique was used to make repeated measurements of spinal cord blood flow (SCBF) in the dorsolateral funiculus of the injured segment before and for 4 hours after injury. In 11 untreated uninjured cats, the mean preinjury SCBF was 12.7 +/- 1.5 ml/100 gm/min. Following contusion, there was a progressive decline in SCBF to 6.8 +/- 0.4 ml/100 gm/min, or 53.5% of the preinjury level at 4 hours. In comparison, the Ca++ antagonists diltiazem and nifedipine (but not verapamil) prevented a significant posttraumatic decrease in SCBF. Similarly, both cyclo-oxygenase inhibitors (ibuprofen and meclofenamate) maintained SCBF within normal limits (10 ml/100 gm/min or greater). However, neither TXA2 synthetase inhibition nor the stable PGI2 analogue alone had a significant effect in preventing ischemia, whereas a combination of the two agents did serve to support SCBF. The most impressive preservation of posttraumatic SCBF, however, was observed in the antioxidant-treated animals. Based upon these results, a hypothesis is presented concerning the pathogenesis of posttraumatic central nervous system ischemia which integrates an injury-induced rise in intracellular Ca++, the increased synthesis of vasoactive prostanoids (such as prostaglandin F2 alpha and TXA2), and progressive microvascular lipid peroxidation.