异丙酚对大鼠中枢多巴胺再摄取的抑制作用

目的　观察异丙酚麻醉的大鼠中枢神经系统纹状体中多巴胺转运蛋白的变化,了解异丙酚麻醉时中枢多巴胺增加的调控机制。方法（１）正常ＳＤ大鼠２４只随机分为４组,分别腹腔注射异丙酚 ５０ｍｇ／ｋｇ、７５ｍｇ／ｋｇ、１００ｍｇ／ｋｇ和同容积 １０％脂肪乳剂作对照,腹腔注射后 １０分钟动物断头处死,取脑组织做脑连续切片,进行放射自显影研究;（２）ＳＤ大鼠６只,断头处死迅速取脑组织做脑连续切片,用~（１２５）Ｉ－β－ＣＴＴ为配基做放射受体结合体外抑制实验。结果　腹腔注射１００ｍｇ／ｋｇ异丙酚能明显抑制~（１２５） Ｉ－β－ＣＩＴ与纹状体中多巴胺转运蛋白结合（Ｐ＜０．０５）。体外抑制实验随异丙酚浓度增加,与脑组织多巴胺转运蛋白结合的~（１２５） Ｉ－β－ＣＩＴ的放射活性明显下降。结论异丙酚致中枢多巴胺增加与异丙酚抑制多巴胺转运蛋白对突触中多巴胺的再摄取有关。     

异丙酚对多巴胺转运蛋白转运功能的影响

目的 研究异丙酚对多巴胺转运蛋白(DAT)转运功能的影响。方法 ①应用高表达DAT的中华仓鼠卵巢(CHO)细胞,在给予异丙酚后,测定 DAT摄取氢~3H标记的多巴胺(~3H-DA)功能;②应用非线性动力学方法,观测异丙酚作用时,DAT最大摄取速度(Vmax)和米氏常数(Km)的变化。结果 异丙酚显著降低了高表达多巴胺转运蛋白的中华仓鼠卵巢(CHO/DAT)细胞对多巴胺(DA)的摄取能力;异丙酚药物转运动力学实验表明,异丙酚降低了CHO/DAT对~H-DA的Vmax,对照细胞和异丙酚用药细胞Vmax分别为16.67pmol·min~(-1)·10~(-5)cells和11.6pmol·min~(-1)·10~(-5)cells,但与DAT的亲和力未发生改变,Km分别为0.46pmol·L~(-1)和0.53pmol·L~(-1)。结论 异丙酚以非竞争性的方式抑制了DAT的转运功能,降低了多巴胺(DA)的再摄取,导致突触间隙DA浓度升高,从而增强了中枢多巴胺能神经信息的传递。     

异丙酚对大鼠中枢多巴胺再摄取的抑制作用

目的 观察异丙酚麻醉的大鼠中枢神经纹状体中多巴胺转运蛋白的变化，了解异丙酚麻醉时中枢多巴胺增加的调控机制。方法 （１）正常ＳＤ大鼠２４只随机分为４组，分别腹腔注射异丙酚５ｍｇ／ｋｇ，７５ｍｇ／ｋｇ，１９００ｍｇ／ｋｇ和同容积１０％脂肪乳剂作对照，腹腔注射后１０分钟动物断头处死，取脑组织做脑连续切片，进行放射自显影研究；（２）ＳＤ大鼠６只，断头处死迅速取脑组织做脑连续切片，用＾１２５Ｉ－β－ＣＩＴ为     

异丙酚对大鼠不同脑区兴奋性和抑制性氨基酸类神经递质释放的影响

目的 评价异丙酚对大鼠皮质区、丘脑区、海马区和纹状体区兴奋性和抑制性氨基酸类神经递质释放的影响,探讨异丙酚麻醉的中枢机制.方法 Wistar大鼠12只,雌雄各半,体重300～350 g,麻醉后参照Paxinos和Waston定位图谱按照不同脑区坐标预埋微透析探针套管,恢复4 d后,随机分为2组(n=6):对照组和异丙酚组,分别尾静脉输注生理盐水6 ml/kg和异丙酚120 mg·kg-1·h-1,1 h后收集微透析液,采用高效液相色谱-电化学法测定微透析液中氨基酸类神经递质(谷氨酸、天冬氨酸、γ-氨基丁酸和甘氨酸)浓度.结果 与对照组比较,异丙酚组各脑区谷氨酸、天冬氨酸水平降低,γ-氨基丁酸、甘氨酸水平升高(P<0.05或0.01).结论 异丙酚抑制大鼠不同脑区(皮质区、丘脑区、海马区和纹状体区)兴奋性氨基酸类神经递质释放而增强抑制性氨基酸类神经递质释放,可能是其麻醉的中枢机制之一.     

异丙酚麻醉对新生大鼠海马β-分泌酶1表达和β淀粉样蛋白1-42含量的影响

目的 评价异丙酚麻醉对新生大鼠海马β-分泌酶1(BACE1)表达和β淀粉样蛋白1-42(Aβ1-42)含量的影响.方法 新生7d清洁级健康SD大鼠90只,体重12 ～ 16 g,雌雄各半,采用随机数字表法,将其随机分为3组(n=30):对照组(C组)、异丙酚单次麻醉组(SP组)和异丙酚重复麻醉组(RP组).C组腹腔注射生理盐水7.5 ml/kg,1次/d,连续7 d;SP组腹腔注射生理盐水7.5 ml/kg,1次/d,连续6d,第7天腹腔注射异丙酚75 mg/kg; RP组腹腔注射异丙酚75 mg/kg,1次/d,连续7d.于第7天注射完毕后15 min,各组随机取6只大鼠,心室穿刺采血,测定血糖并行血气分析,于注射完毕后1、3和7d时各组随机取8只大鼠,分离海马,采用Western bolt法检测BACE1表达,采用ELISA法测定Aβ1-42含量.结果 与C组和SP组比较,RP组各时点大鼠海马BACE1及及Aβ1-42水平升高(P＜0.01);C组和SP组各时点大鼠海马BACE1及Aβ1-42水平比较差异无统计学意义(P＞0.05).结论 异丙酚多次麻醉新生大鼠海马BAGE1表达上调,Aβ1-42含量升高,可能是其导致远期认知功能障碍的机制之一；异丙酚单次麻醉无此作用.     

异丙酚对β-淀粉样蛋白诱导大鼠皮层神经元损伤的影响

目的 探讨异丙酚对β-淀粉样蛋白(β-AP)诱导大鼠皮层神经元损伤的影响.方法 孕18 dSD大鼠,体外分离皮层神经元,5×104个/孔,每孔200μl接种于96孔培养板上,培养7 d.实验一:取15孔神经元随机分为5组(n=3):对照组;损伤组;异丙酚预防给药Ⅰ组加入β-AP 25μmol/L前24 h加入异丙酚50μmol/L,再孵育24h;异丙酚预防给药Ⅱ组同时加入异丙酚50 μmol/L和β-AP 25μmol/L,孵育24 h;异丙酚治疗给药组加入β-AP 25μmol/L后6 h,加入异丙酚50μmol/L,再孵育18 h.实验二:取18孔神经元随机分为6组(n=3):对照组;损伤组;脂肪乳剂组加入β-AP 25μmol/L后6 h,加入等容量10%脂肪乳剂,再孵育18 h;不同浓度异丙酚组加入β-AP 25μmol/L后6 h,分别加入异丙酚1、10、50 βmol/L,再孵育18 h.测定神经元乳酸脱氢酶(LDH)释放量和神经元活力.采用TUNEL法、Hoechst33342染色观察细胞凋亡情况,计算细胞凋亡率.结果 实验一:与损伤组比较,异丙酚预防给药组LDH释放量差异无统计学意义(P＞0.05),异丙酚治疗给药组神经元LDH释放量减少(P＜0.05).实验二:与损伤组比较,异丙酚50μmol/L组神经元LDH释放量减少,神经元活力升高,细胞凋亡率降低(P＜0.05).结论 异丙酚50 μmol/L治疗性给药可减轻β-淀粉样蛋白诱导大鼠皮层神经元损伤,预防性给药对其无影响.     

异丙酚麻醉对电休克诱发抑郁大鼠海马Tau蛋白过度磷酸化的影响

目的 探讨异丙酚麻醉对电休克诱发抑郁大鼠海马Tau蛋白过度磷酸化的影响.方法 选取Open-field测试总分为30～120分的雌性WKY大鼠32只,24周龄,体重200～250 g,采用随机数字表法,将其随机分为4组(n=8):对照组(C组)、异丙酚组(P组)、电休克组(E组)和异丙酚+电休克组(PE组).C组腹腔注射生理盐水5ml;P组腹腔注射100 mg/kg异丙酚5ml;E组腹腔注射生理盐水5ml,15 min后施行电休克治疗;PE组腹腔注射100 mg/kg异丙酚5ml,15 min后施行电休克治疗.电休克治疗结束24h时,采用Morris水迷宫测定大鼠认识功能.认知功能测试完毕6h时,处死大鼠,取海马组织,检测磷酸化Tau蛋白的表达.结果 与C组比较,P组、E组和PE组逃避潜伏期延长,游泳时间缩短,P组海马磷酸化Tau蛋白表达下调,E组海马磷酸化Tau蛋白表达上调(P＜0.05),PE组海马磷酸化Tau蛋白表达差异无统计学意义(P＞0.05);与E组比较,PE组逃避潜伏期缩短,游泳时间延长,海马磷酸化Tau蛋白表达下调(P＜0.05).结论 异丙酚麻醉改善电休克诱发抑郁大鼠认知功能障碍的机制与抑制海马Tau蛋白过度磷酸化有关.     

靶控输注异丙酚不同麻醉深度下兔纹状体多巴胺及cAMP的变化

目的研究异丙酚不同麻醉深度下兔纹状体多巴胺(DA)及cAMP的变化.方法随机选取40只日本大耳兔,雌雄不拘.10只兔颈外静脉连接Graseby 3500注射泵进行靶控输注(TCI),异丙酚靶血药浓度最初为6μg/ml,达平衡后2 min以0.3μg/ml速度递增.此期间每30 s观察咀嚼反射,以咀嚼反射消失作为浅麻醉标志,以夹尾后无体动反应为深麻醉标志,确定不同麻醉深度下所需的异丙酚靶控血药浓度(Cp),并用高效液相色谱法测定异丙酚血药浓度(Cm),计算预期误差(PE)的百分数(PE%)、预期误差的中位数(MDPE)、预期误差绝对值的中位数(MDAPE),评价TCI系统的准确性.30只兔随机分为三组对照组、浅麻醉组和深麻醉组各10只.对照组不予以异丙酚,浅麻醉组和深麻醉组应用异丙酚TCI系统,严格控制麻醉于不同深度,持续1h后断头处死,迅速冰上分离纹状体,测定DA、高香草酸(HVA)、cAMP含量.结果浅麻醉和深麻醉状态下异丙酚Cp及BIS分别为(9.25±0.12)μg·ml-1,63±4;(11.63±0.29)μg·ml-1,32±6.MDPE和MDAPE分别为-25.7%和29.6%,DA代谢水平随麻醉深度的增加而显著性增加(P＜0.05),cAMP含量浅麻醉组及深麻醉组均高于对照组(P＜0.05),但浅麻醉组与深麻醉组之间差异无显著性(P＞0.05).结论随异丙酚麻醉深度的增加纹状体DA含量增加,并可能通过作用于D1受体,引起胞内cAMP大量增加.     

异丙酚对止血带引起的下肢缺血再灌注损伤的影响

目的探讨临床剂量异丙酚对止血带引起的下肢缺血再灌注损伤的影响.方法19例行双膝关节置换手术病人分为2组,异氟醚组(Ⅰ组,n=10)咪唑安定(0.15mg@kg-1),维库溴铵(0.1mg@kg-1),芬太尼(3μg@kg-1)诱导插管后吸入异氟醚(0.8%);异丙酚组(P组,n=9)异丙酚(2mg@kg-1),维库溴铵(0.1mg@kg-1),芬太尼(3μg@kg-1)诱导插管后连续输注异丙酚(8mg@kg-1@h-1).两组病人均复合连续硬膜外麻醉.分别于止血带充气前及放气后5、10、20min自股静脉抽血测定血浆肌酸磷酸激酶(CPK)、乳酸脱氢酶(LDH),丙二醛(MDA)及血栓素(TXB2)、6-酮-前列腺素(6-keto-PGF1α)的水平.结果与止血带充气前相比,Ⅰ组再灌注后10、20min CPK和LDH升高,再灌注后5min MDA升高(P<0.05);P组再灌注后5、10、20min CPK、MDA无显著性差异,10、20minLDH降低(P<0.05),且低于Ⅰ组相应时间点水平(P<0.05),再灌注后5min MDA明显低于Ⅰ组(P<0.05);P组5、10、20min TXB2和6-keto-PGFlα均明显低于0min及Ⅰ组相应时间点水平(P<0.05).结论临床剂量输注异丙酚(8mg@kg-1@h-1)对止血带引起的下肢缺血再灌注损伤有一定的减轻作用,表现为脂质过氧化物的清除,骨骼肌细胞受损程度的减轻,血栓素水平的降低.     

比较地氟醚与异丙酚在电视胸腔镜手术中对病人氧合的影响

目的比较地氟醚和异丙酚在电视胸腔镜手术单肺通气中对病人的氧合影响.方法择期行电视胸腔镜手术病人20例,ASAⅡ～Ⅲ级,随机分为地氟醚组(D组)和异丙酚组(P组),每组10例.麻醉诱导P组或D组分别用芬太尼4μg@kg-1、维库溴铵0.1mg@kg-1、琥珀胆碱100mg,异丙酚2mg@kg-1(P组)或2.5%硫喷妥钠5mg@kg-1(D组),以2～8mg@kg-1@h-1异丙酚(P组)或2%～4%地氟醚(D组)、芬太尼、维库溴铵维持麻醉.静脉诱导后经口腔插入Carlen双腔支气管导管.监测术中MAP及HR的变化,并分别于术前、TLV30min、OLV30min、OLV60min取桡动脉血做血气分析.结果两组病人均于单肺通气后PaO2虽明显下降(P＜0.05),但PaO2＞60mmHg,组间无显著性差异.D组术中MAP明显低于术前,而P组无显著性变化.结论地氟醚与异丙酚均可安全地应用于单肺通气手术的麻醉.     

Insulin-like growth factor I stimulates glucose uptake and expression of glucose transporter 1 in cultured mesangial cells

Background. Glomerular mesangial cells were found to have a considerable number of receptors for insulin-like growth factor I (IGF-I) and to proliferate in response to IGF-I. However, the mechanism of the metabolic actions of IGF-I in mesangial cells has not yet been fully elucidated. Methods. In order to clarify the effect of IGF-I on glucose metabolism in mesangial cells, we performed a kinetic analysis of 2-deoxyglucose (2-DOG) uptake, the first step of glucose metabolism, and examined the gene and protein expression of glucose transporter 1 (GLUT 1), a major facilitative glucose transporter in mesangial cells. Results. IGF-I was able to increase 2-DOG uptake significantly after 12 h, and the kinetic analysis of 2-DOG uptake revealed that IGF-I increased maximum velocity (Vmax) without changing Michaelis constant (Km). The expression of GLUT 1 mRNA was increased after the exposure to IGF-I and reached the maximal level at 6 h, followed by an increase in its protein expression. Conclusions. These results suggest that IGF-I plays an important role in glucose metabolism in glomerular mesangial cells by enhancing glucose transport through an increase in the expression of GLUT 1. Received: October 14, 1996 / Accepted: March 19, 1999     

高糖刺激肾小球系膜细胞葡萄糖转运蛋白4及p21的表达及其意义

目的探讨早期糖尿病肾病(DN)肾小球系膜细胞(GMC)中葡萄糖转运蛋白(GLUT)4、p21mRNA表达变化及其与GMC肥大的关系。方法大鼠1097系膜细胞株分为高糖组、甘露醇组、不同浓度胰岛素组、高糖加不同浓度胰岛素组、正常对照组。用RT-PCR法检测各组GLUT4mRNA、p21mRNA的表达。流式细胞仪测各组GMC体积大小。结果正常对照组GMC有一定GLUT4mRNA、p21mRNA表达。高糖组GLUT4mRNA表达明显下降,p21mRNA表达明显增加。胰岛素刺激GMCGLUT4mRNA表达存在浓度依赖关系。p21mRNA表达越高,细胞前向角度散射光(FSC)越强,GMC体积越大。结论高糖刺激导致GMC肥大,GMC的p21mRNA表达上调和GLUT4mRNA表达下调与DN早期GMC肥大-肾小球肥大有关。     

谷氨酸转运体与疼痛

谷氨酸是N-甲基-D-天门冬氨酸(N-methyL-D-aspartate,NMDA)受体的天然配体,如果持续激动就会产生细胞毒性.谷氨酸转运体能从胞外向胞内摄取谷氨酸,以减少对NMDA受体的激动,保护神经元不受谷氨酸毒性影响.新近的研究表明,谷氨酸转运体通过调节细胞外谷氨酸浓度在疼痛过程中也发挥着重要作用.     

Human renal organic anion transporter 4 operates as an asymmetric urate transporter

Human organic anion transporter 4 (hOAT4) is located at the apical membrane of proximal tubule cells and involved in renal secretion and reabsorption of endogenous substances as well as many drugs and xenobiotics. This study reevaluated the physiologic role, transport mode, and driving forces of hOAT4. 6-Carboxyfluorescein (6-CF) uptake into HEK293 cells that stably expressed hOAT4 was saturable, resulting in a K(m) of 108 muM. 6-CF as well as [(3)H]estrone sulfate ([(3)H]ES) accumulation by HEK293-hOAT4 cells were abolished by ES, dehydroepiandrosterone sulfate, sulfinpyrazone, benzbromarone, and probenecid, whereas several OA, including p-aminohippurate (PAH), lactate, pyrazinoate, nicotinate, glutarate, and the diuretic hydrochlorothiazide (HCTZ) exhibited a slight or a NS inhibitory effect. PAH and glutarate are not taken up by HEK293-hOAT4 cells, but they trans-stimulated 6-CF and [(3)H]ES uptake, indicating an asymmetric interaction of hOAT4 with these substrates. In chloride-free medium, HEK293-hOAT4-mediated [(3)H]PAH efflux was almost abolished, whereas addition of ES restored it comparable to Ringer solution, consistent with a physiologic ES/PAH or PAH/Cl(-) exchange mode of hOAT4. Moreover, an acidification of the uptake medium increased 6-CF as well as [(3)H]ES uptake, which was reduced by nigericin, suggesting that hOAT4 also can operate as an OA/OH(-) exchanger. hOAT4 facilitates substantial uptake of [(14)C]urate, which was elevated 2.6-fold by intracellular HCTZ. Thus, hOAT4 is the long-postulated, low-affinity apical urate anion exchanger that facilitates HCTZ-associated hyperuricemia.     

胰腺癌细胞膜平衡型核苷转运载体和集中型核苷转运载体的检测

目的：检测胰腺癌细胞膜上Na+非依赖的平衡型核苷转运载体（ENT）和Na+依赖性的集中型核苷转运载体（CNT）,并对ENT进行定量检测。方法：将胰腺癌细胞株（Panc-1）在含潘生丁（100 μmol/L）的培养基中分别温育8,15,60,120 min,收集细胞用乙腈裂解,荧光分光光度计测定细胞悬液中潘生丁的荧光强度,依据平行悬液中的细胞数量计算出单个细胞表面ENT的数量;再将Panc-1分别在含5-氟尿嘧啶（5-FU）和5-FU+潘生丁两种培养基中分别温育15,30,60,120,240 min,毛细管区带电泳法测定5-FU含量;根据平行悬液中的细胞数量和单细胞体积计算单细胞中5-FU的浓度,间接判定细胞膜上是否存在CNT载体。结果：Panc-1在含潘生丁的培养基温育8 min后即能检测到细胞的荧光强度,15 min达高峰20.2×10-19 mol;借助潘生丁测得单个细胞表面有1.25×105个ENT。用潘生丁阻断ENT后,5-FU仍可被转运入胰腺癌细胞中,且细胞内的5-FU最高浓度达到（138.3±9.77）mg/L,明显高于培养基中5-FU的浓度（P=0.011）。结论：与潘生丁结合后,通过荧光法可以定量检测细胞表面的ENT;通过阻断ENT并测定细胞中5-FU浓度,可以判断胰腺癌细胞膜上存在CNT,从而对合理应用化疗药物,提高化疗效果提供依据。

     

The effect of fresh gas flow during induction of anaesthesia on sevoflurane usage: a quality improvement study

Reducing fresh gas flow during inhalational anaesthesia results in cost savings and decreases environmental impact. We are interested in the influence of fresh gas flow on the early (induction) phase of overall fresh gas flow and vapour consumption. This stage is often excluded in studies of fresh gas flow. Data were collected from 3199 sevoflurane anaesthetics over an 11-month period in four operating theatres. We determined fresh gas flow at different stages of anaesthesia, and developed an explanatory model for the influence of the ‘induction’ period. Following a three-month collection of baseline data we emphasised the importance of the early phase to our department repeatedly over a two-week period. We explored the relationship between fresh gas flow and total vapour usage, and used a simple mathematical model to explore the effect of changes in the fresh gas flow and duration of the ‘induction’ phase. Mean fresh gas flow was 1.15 l.min⁻¹ in the baseline period and 0.91 l.min⁻¹ in the two months following our educational effort (p = 0.0005). In the following six months, mean fresh gas flow was 1.17 l.min⁻¹ (p = 0.7726 compared with baseline). These results were driven by changes in both fresh gas flow and duration of the initial high-flow period. We found some correlation (R² = 0.85) between overall fresh gas flow and vapour consumption; a 1 l.min⁻¹ increase in fresh gas flow consumes an additional 18 ml.hr⁻¹ of liquid sevoflurane. This preliminary study demonstrates that an episode of high fresh gas flow at the start of anaesthesia has a large and modifiable effect on overall fresh gas flow and vapour consumption. We also confirmed the linear relationship between fresh gas flow and vapour usage.     

Interaction of isoflurane with the dopamine transporter

BACKGROUND: Isoflurane administration is known to increase extracellular dopamine (DA) concentration. Because the dopamine transporter (DAT) is a key regulator of DA, it is likely affected by isoflurane. This study investigates the hypothesis that isoflurane inhibits DA reuptake by causing DAT to be trafficked into the cell. METHODS: Rhesus monkeys were scanned with positron emission tomography (PET) using [18F]FECNT (a highly specific DAT ligand) while anesthetized with 1% isoflurane. The isoflurane was increased to 2%, and the animals were rescanned. Uptake was analyzed with the tissue reference method using the cerebellum as the reference tissue to determine the binding potential in the putamen. Immunohistochemistry and Western blot analyses were performed in rats to determine if isoflurane administration would change the total amount of DAT. Rats breathed air plus 2% isoflurane for 30 min, and then striatal DAT assays were rapidly performed. immunocytochemistry experiments were performed using human embryonic kidney (HEK) cells stably transfected with human DAT. The cells were exposed to 4% isoflurane for 1 h while the location of DAT was observed with fluorescent confocal microscopy. RESULTS: The [18F]FECNT binding potential in rhesus monkeys decreased by 63 +/- 6% (SEM, n = 5) when isoflurane was increased from 1 to 2% as compared with no significant change (0.7 +/- 2.5%; SEM, n = 5) when the isoflurane concentration was not changed (P < 0.001). No difference in DAT staining between isoflurane-treated and control rats was apparent from visual inspection, and quantitative Western blot analyses showed no significant change in total DAT protein. After isoflurane treatment, focal puncta of intense fluorescence was visible inside the HEK cells. CONCLUSIONS: The experiments indicate that DAT is trafficked into the cell by isoflurane without changing the total amount of DAT in the striatum. The PET data are consistent with this finding, provided that intracellular DAT acquires a conformation that has low affinity for [18F]FECNT. Thus, [18F]FECNT appears to be an excellent agent for measuring plasma membrane-expressed DAT and evaluating DAT trafficking.