Evidence that dl-propranolol increases thymidine kinase activity,cell mitosis,and beta-adrenoceptors during rat liver regeneration

BACKGROUND: Adrenoceptor stimulation has been described as an important factor in liver regeneration. We examined the effects of the beta-adrenoceptor antagonist, dl-propranolol, during early steps of regeneration after partial hepatectomy in rat. METHODS: Thymidine kinase (TK) activity, cell mitosis, and beta-adrenoceptors were measured after a single intraperitoneal (i.p.) injection of dl-propranolol (10 mg/kg) immediately following 70% partial hepatectomy. Enzyme activity was measured as [3H] thymidine (dThd) monophosphate; mitotic index was determined after tissue staining, and beta-adrenoceptors were quantified by saturation binding of [3H] dihydroalprenolol. Liver regeneration was followed for 3 days. RESULTS: dl-Propranolol increased TK activity as early as 12 h postsurgery, after which it leveled off at 24 h and declined at later times; mitotic index increased from 12 to 48 h after injection and beta-adrenoceptors augmented at 24 h compared to partial hepatectomy alone. CONCLUSIONS: dl-Propranolol up-regulated beta-adrenoceptors early after partial hepatectomy with an increase in TK activity and augmented hepatocyte mitosis. These data may suggest that dl-propranolol modulates, probably via beta-adrenoceptor blockade, early steps of liver regeneration.     

Hepatic sinusoidal endothelial cells promote hepatocyte proliferation early after partial hepatectomy in rats

BACKGROUND: We undertook this study in rats to investigate the role of hepatic sinusoidal endothelial cells (SECs) in hepatocyte proliferation early after partial hepatectomy and the regulatory mechanisms involved. METHODS: The animal model of 70% hepatectomy was made. Hepatic SECs and hepatocytes were isolated and cultured according to the method of Braet et al. with some modifications. Levels of nitric oxide (NO), interleukin-6 (IL-6), and hepatic growth factor (HGF) in the supernatants of hepatic SEC cultures were measured, and the expression of HGF mRNA by hepatic SECs was analyzed. The relationship between the supernatants of hepatic SEC cultures and hepatocyte proliferation was probed. (3)H-thymidine incorporation and the proliferating cell nuclear antigen (PCNA) labeling index of hepatocytes were used as signs of hepatocyte proliferation. RESULTS: Levels of NO, IL-6, and HGF in the supernatants of hepatic SECs cultures were increased markedly 6 and 24 h after hepatectomy and then were decreased gradually. The expression of HGF mRNA by cultured SECs was increased markedly 6 and 24 h after hepatectomy, with a peak 6 h after hepatectomy. The PCNA labeling index and (3)H-thymidine incorporation of hepatocytes started to increase 6 h after hepatectomy, with a peak at 24 h. Hepatic SECs were isolated from rats 24 h after partial hepatectomy and cultured for 24 h, and the culture supernatants were obtained. The supernatants not only significantly enhanced the PCNA labeling index and (3)H-thymidine incorporation of proliferating hepatocytes isolated from rats after partial hepatectomy but also obviously increased the DNA synthesis of quiescent hepatocytes from the control rats. The extent of hepatocyte proliferation was closely related to the amount of the SEC culture supernatants added in both rats after partial hepatectomy and control rats. CONCLUSIONS: These results suggest that cytokines (such as IL-6, HGF and NO) secreted by SECs play important roles in liver regeneration early after partial hepatectomy. We speculate that activated hepatic SECs secrete some substances that induce or trigger liver regeneration after partial hepatectomy.     

乌司他丁对肝大部切除合并缺血再灌注损伤后肝再生及TNF-α/IL-6/STAT-3 信号通路的影响

摘要：目的探讨乌司他丁（UTI）预处理对大鼠70%肝切除合并缺血再灌注损伤后残肝再生和TNF-α/IL-6/STAT-3信号通路的
影响。方法健康清洁级雄性SD 大鼠120 只,体质量230~280 g,随机分为单纯肝切除组（PH）、肝切除合并缺血再灌注组
（PHIR）和乌司他丁组（UTI）,40只/组。PH组不阻断残肝血流;PHIR组阻断血流30 min后恢复灌注;UTI组于缺血前5 min经尾
静脉给予UTI 50 000 U/kg。再灌注后1、6、12、24、48 h取各组大鼠残肝组织,测定残肝再生度、PCNA阳性率,TNF-α、IL-6水平,
STAT-3、CyclinD1、Cdk4mRNA表达及CyclinD1、Cdk4 蛋白表达水平。结果UTI组24 h 和48 h 肝再生度和PCNA阳性率较
PHIR组显著升高（P<0.05）;UTI组早期TNF-α、IL-6水平较PHIR组显著降低（P<0.05）,但再灌注晚期IL-6水显著高于PHIR组
（P<0.05）;UTI组24 h 和48 h STAT-3、CyclinD1、Cdk4 mRNA表达及CyclinD1 和Cdk4 蛋白表达水平均显著高于PHIR组（P<
0.05）。结论乌司他丁对肝大部切除合并缺血再灌注损伤后残肝的再生具有促进作用,其机制与激活IL-6/STAT-3信号通路,
促使肝细胞CyclinDl-Cdk4复合物合成,促进肝细胞增殖有关。
     

D-氨基半乳糖与脂多糖对小鼠肝脏损伤后再生修复的影响

目的观察部分肝切除联合D-氨基半乳糖(D-GaIN)、脂多糖对肝损伤后再生修复的影响。方法 40只BALB/c雄性小鼠随机均分为2组。D-GaIN/脂多糖/肝脏部分切除组:腹腔注射D-GaIN(500 mg/kg),1 h后注射脂多糖(50μg/kg);肝脏部分切除组:生理盐水代替D-GaIN和脂多糖,同样方法注射;两组小鼠在第2次腹腔注射24 h后行肝脏1/3切除。观察两组小鼠术后肝脏体质量比值、肝再生率、肝细胞损伤、增殖与肝卵圆干细胞增生。结果肝脏部分切除组术后第9天肝大体结构基本恢复正常,肝再生率为(22.26±105.93)%,而D-GaIN/脂多糖/肝脏部分切除组第14天肝质量较术前仍偏小,肝再生率为(9.49±32.55)%,P<0.001。D-GaIN/脂多糖/肝脏部分切除组术后肝窦和中央静脉充血,库普弗细胞增多;肝脏部分切除组术后第7天有明显肝细胞增殖,D-GaIN/脂多糖/肝脏部分切除组肝细胞增殖甚少。D-GaIN/脂多糖/肝脏部分切除组肝脏术后第3天开始出现肝卵圆干细胞增生,从汇管区开始向肝小叶内延伸以修复损伤。结论 D-GaIN联合脂多糖可部分抑制肝部分切除后小鼠成熟肝细胞增殖,D-GaIN/脂多糖/肝部分切除可诱导肝卵圆干细胞增生。     

缺氧诱导因子-1α基因在成年大鼠局灶性脑缺血中的治疗作用研究

目的构建携带缺氧诱导因子-1α(HIF-1α)基因的重组腺病毒载体,探索HIF-1α对大鼠局灶性脑缺血的治疗作用。方法应用腺病毒表达系统AdEasySystem构建携带缺氧诱导因子-1α和绿色荧光蛋白(GFP)的重组腺病毒(Ad-HIF-1α)并行PCR鉴定。建立大鼠线栓法大脑中动脉缺血再灌注模型,分为Ad-HIF-1α、腺病毒空载体(Ad)、生理盐水(NS)3组;将Ad-HIF-1α、Ad和NS注射到模型鼠缺血侧侧脑室,观察Ad-HIF-1α的分布和绿色荧光持续时间、三组大鼠神经功能缺失评分和2,3,5-三苯基氯化四氮唑(TTC)染色评价Ad-HIF-1α对脑缺血的治疗效果。结果在荧光显微镜下绿色荧光蛋白的表达逐渐向远离侧脑室的部位扩展,在14d时荧光最强,随后逐渐减弱,至28d时荧光基本消失。Ad-HIF-1α治疗组24h大鼠神经功能缺失评分为2.4±0.5,与Ad组(2.6±0.5)和NS组(2.7±0.7)比较差异无统计学意义(P>0.05);48及72hAd-HIF-1α治疗组神经功能缺失评分分别为1.6±0.7和0.9±0.6,与Ad组(分别为2.9±0.6和3.2±0.6)和NS组(分别为3.0±0.7和3.2±0.8)比较差异均有统计学意义(P<0.05);72h时脑组织TTC染色显示Ad-HIF-1α治疗组梗死体积为81.2mm3±1.4mm3,与Ad组(173.9mm3±1.3mm3)和NS组(171.7mm3±6.2mm3)比较差异有统计学意义(P<0.05)。结论Ad-HIF-1α对大鼠局灶性脑缺血具有一定的治疗作用,为HIF-1α基因的进一步研究和临床应用奠定了基础。     

Vascular alpha 1D-adrenoceptor function is maintained during congestive heart failure after myocardial infarction in the rat

BACKGROUND: During congestive heart failure, desensitization of beta-adrenoceptors is related to a lower adrenergic responsiveness in the heart; little is known about alpha 1-adrenoceptors in the vasculature under this condition. We evaluated alpha 1D-adrenoceptor response in aorta and carotid arteries in a model of congestive heart failure (CHF) post-myocardial infarction. METHODS: Noradrenaline-elicited contraction was determined in endothelium-denuded arterial rings from young (10-week-old) Wistar rats in the absence and presence of the alpha 1D-adrenoceptor antagonist BMY 7378 (8-(2-(4-(2-methoxyphenyl)-1-piperazinyl) ethyl)-8-azaspiro(4,5)decane-7,9-dione dihydrochloride) in sham-operated rats and in rats that developed CHF 4 weeks or 7 months after myocardial infarction. RESULTS: In the thoracic aorta, BMY 7378 displaced noradrenaline effect to the right with pA2 values of: sham, 8.58 +/- 0.12; CHF, 8.36 +/- 0.13, and sham, 8.56 +/- 0.10; CHF, 7.99 +/- 0.13 at 4 weeks and 7 months after myocardial infarction, respectively. While in carotid arteries, the pA2 values were: sham, 8.43 +/- 0.19; CHF, 8.81 +/- 0.19, and sham, 8.35 +/- 0.18; CHF, 8.29 +/- 0.08 at 4 weeks and 7 months after myocardial infarction, respectively. When adult (7-month-old) rats were subjected to myocardial infarction, CHF was not installed and pA2 values were similar and high in both sham and infarcted rats. CONCLUSIONS: These results indicate that alpha 1D-adrenoceptors remained as the main receptors involved in contraction in aorta and carotid arteries, irrespective of CHF duration.     

The hypotensive effect of BMY 7378 involves central 5-HT1A receptor stimulation in the adult but not in the young rat

BACKGROUND: Stimulation of central 5-hydroxytryptamine-1A (5-HT(1A)) receptors produces hypotension and bradycardia. We describe BMY 7378 (8-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-8-azaspiro[4.5]decane-7,9 dione) effects in cardiovascular function and [(3)H] 8-OH-DPAT (8-hydroxy-2-(di-n-propyl-amino) tetralin) binding sites in rat brain of different ages. METHODS: BMY 7378 was administered to anesthetized male Wistar rats (1, 3 and 6 months old) and blood pressure and heart rate were continuously recorded. Saturation of [(3)H] 8-OH-DPAT binding to 5-HT(1A) sites in brain membranes was determined. RESULTS: Basal diastolic blood pressure increased with age, 85 +/- 2, 106 +/- 3, and 113 +/- 2 mmHg for 1-, 3- and 6-month-old rats, respectively (p <0.05 among groups). BMY 7378 induced significant dose- and age-dependent hypotension. The selective 5-HT(1A) receptor antagonist, WAY 100635 (N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]N-(2-pyridinyl) cyclohexanecarboxamide), antagonized BMY 7378 effects in 6 month-old but not in younger rats. [(3)H] 8-OH-DPAT binding sites decreased in hippocampi and brainstem with maturation. CONCLUSIONS: Data suggest that BMY 7378 is a hypotensive agent in the rat, but that its actions are mediated, in part, by central 5-HT(1A) receptor stimulation in the adult and by a nonserotonergic mechanism in the young rat.     

大鼠肝再生时肝PBR、Bcl-2、Bax基因mRNA的表达

目的:探讨肝细胞线粒体通透性转换(permeability transition, PT)的主要调节蛋白外周型苯二氮NFDB2类受体(PBR)、Bcl-2家族成员Bcl-2、Bax在肝再生过程中的表达情况,探讨上述基因表达与线粒体PT的关系.方法:健康成年雄性SD大鼠,随机分为3组:肝切除组,切除肝左叶和中叶部分约全肝的70%;假处理组,同样麻醉和开腹,但不切肝;正常组.手术后3、6、12、24、48、72、120 和168 h分别以半定量RT-PCR法检测PBR、Bcl-2、Bax在肝再生过程中mRNA表达的动态变化.结果:肝再生过程中PBR基因表达降低,但与假处理组无显著差异;Bcl-2在肝切除后3 h和120 h表达显著高于对应的假处理组和正常组(P<0.05);Bax mRNA表达低于正常组和假处理组,其中在肝切除后12 h和72 h时显著低于相应的假处理组(P<0.05).结论:PBR、Bax、Bcl-2在肝再生过程中表达变化可能与线粒体PT时相变化有关.     

大鼠肝移植缺血再灌注损伤对肝细胞凋亡、胀亡及再生的影响

目的：通过对大鼠原位肝移植缺血再灌注损伤所致肝细胞两种细胞死亡方式的动态研究，结合细胞再生情况。探讨减轻此类损伤的途径．方法：SD大鼠随机分为5组，对照组(n=5)麻醉后开腹取材；其余4组(n=40，每组5对)建立大鼠同种异体原位肝移植模型，分别于术后0、1、12和72h取材．(1)流式细胞仪上机检测Annexinv与碘化丙锭混匀双染色的肝细胞，计数正常、胀亡、凋亡、坏死4种细胞百分数；(2)流式细胞仪检测G1期、S期、G2期肝细胞，计算增殖指数．结果：与对照组比较，供肝冷缺血1h后凋亡细胞显著增多，再灌注后继续增多，并于72h逐渐下降；坏死和胀亡细胞变化不大．G-2期细胞、增殖指数于再灌注后显著增加，在72h仍处于高峰．结论：肝移植过程中细胞凋亡是肝细胞死亡的主要形式，肝移植后存在细胞增殖，增强肝细胞的再生能力也是减轻损伤的一种途径．再灌注期凋亡的作用和机制均值得进一步研究．     

人重组蛋白PDCD5抑制胶原诱导性关节炎大鼠来源的淋巴细胞增殖和炎性细胞因子分泌并促进活化的 淋巴细胞凋亡

目的研究腹腔注射人重组蛋白PDCD5（rhPDCD5）对胶原诱导性关节炎（CIA）大鼠脾脏来源的活化淋巴细胞的作用,探 讨rhPDCD5对活化的脾细胞发挥免疫抑制作用的机制。方法将雌性Wistar大鼠随机分为正常对照组,CIA动物模型+卵白蛋 白（OVA）治疗组,CIA动物模型+rhTNFR:Fc治疗组,CIA动物模型+ rhPDCD5治疗组。第0天建立胶原诱导性类风湿性关节炎 大鼠模型,第2 天到26 天腹腔注射给药。第28 天取脾脏制成单细胞悬液,体外用CII (20 μg/mL)和anti-CD3 (1 μg/mL)+anti- CD28（2 μg/mL）分别刺激活化48 h和72 h。ELISA检测细胞上清中细胞因子干扰素-γ（IFN-γ）和白介素-17A（IL-17A）的水平; [3H]掺入法检测活化脾细胞的增殖;流式细胞技术检测活化的CD4+ T淋巴细胞的凋亡。结果rhPDCD5处理的CIA大鼠来源 的脾细胞经CII和anti-CD3+anti-CD28分别刺激活化之后,分泌的细胞因子IFN-γ 和IL-17A水平下降,增殖能力下降,CD4+ T 淋巴细胞凋亡百分比上调。结论rhPDCD5通过抑制活化的脾细胞分泌炎性细胞因子,抑制活化的脾细胞增殖,促进活化的 CD4+ T淋巴细胞凋亡多条途径发挥免疫抑制作用。     

胚鼠宫内缺血缺氧脑损伤中Wnt信号通路关键分子的表达变化

目的探讨Wnt信号通路与胚鼠宫内缺血缺氧脑损伤的关系。方法将孕15~17d的SD大鼠随机分为实验组和对照组。实验组钳夹双侧子宫动脉30min建立宫内缺血缺氧模型,分别在缺血再灌注24、48、72h后留取胚脑标本。对照组不钳夹子宫动脉,与实验组的对应时间点留取标本。采用尼氏染色和Caspase-3免疫组化检测两组神经元的凋亡情况。Western Blotting检测Wnt信号通路中关键信号分子β-catenin和GSK-3β的表达变化。结果实验组再灌注后不同时间点尼氏小体嗜染性降低,部分溶解。Caspase-3阳性细胞数较对照组升高,其中对照组为12.71±1.42(24h)、11.45±1.50(48h)、14.10±1.29(72h),实验组为26.29±1.64(24h)、32.38±1.05(48h)、39.20±1.88(72h),差异均具有统计学意义(P<0.05)。Western Blotting显示β-catenin蛋白表达在实验组与对照组之间差异无统计学意义(P>0.05),而GSK-3β实验组的相对表达量较对照组显著增高,其中对照组为1.75±1.07(24h)、1.34±1.03(48h)、1.48±1.10(72h),实验组为3.25±1.34(24h)、2.99±1.26(48h)、3.10±1.35(72h),差异均具有统计学意义(P<0.05)。结论Wnt信号通路在胚鼠宫内缺血缺氧脑损伤中可能发挥重要作用。     

肝细胞生长因子对多囊肾病囊肿衬里上皮细胞增殖及细胞外基质合成的影响

目的：研究重组人肝细胞生长因子（rhHGF）对常染色体显性遗传型多囊肾病（ADPKD）囊肿衬里上皮细胞增殖及细胞外基质合成的影响。方法：用^3H-TdR掺入法测定不同浓度（0．5、1、2．5、5ng/ml)rhHGF作用48h以及最适浓度的rhHGF分别作用24、48、72h ADPKD囊肿衬里上皮细胞系细胞的增殖情况;并分别用^3H-脯氨酸掺入法和放免法测定最适浓度rhHGF作用最佳时间后ADPKD囊肿衬里上皮细胞系细胞胶原及层粘连蛋白的合成情况。结果：rhHGF促进了ADPKD囊肿衬里上皮细胞增殖及胶原和层粘连蛋白的合成,以1ng/ml持续作用48h最为显。结论：rhHGF对体外培养的ADPKD囊肿衬里上皮细胞增殖及细胞外基质合成有明显的促进作用。     

大鼠肝再生过程中肝组织游离氨基酸谱变化

作者观察了大鼠肝部分切除(66%)后肝再生过程中1、3、5、10、20天肝组织游离氨基酸谱、肝重和肝细胞核分裂指数的变化。结果表明:①肝部分切除术后残肝重量增加迅速,术后10天基本恢复至术前肝重,肝细胞核分裂指数术后第1天明显升高,第3天时达高峰,以后逐渐下降,恢复正常。②肝组织游离氨基酸含量术后第1天明显升高,第3天时达高峰,以后逐渐降低,第5天时 GLY、MET、LYS 降至正常,其它氨基酸在术后第20天时恢复正常,说明氨基酸代谢变化贯穿于肝再生的全过程。肝细胞核分裂指数变化与氨基酸含量变化呈一致性正相关,提示氨基酸在肝再生过程中对调节肝细胞分裂增殖具有重要作用。     

新型气体信号分子二氧化硫对自发性高血压大鼠主动脉平滑肌细胞增殖和凋亡的影响

OBJECTIVE: To explore the effects of sulfur dioxide (SO2) on the proliferation and apoptosis of aorta smooth muscle cells in hypertension rats and possible mechanism thereof. METHODS: Sixteen 4-week-old male spontaneously hypertensive rats (SHRs) were randomly divided into 2 equal groups: control and Na2SO3/NaHSO3 (a SO2 donor)-treated group. Eight 4-week-old male WKY (Wistar Kyoto) rats were assigned for normal control group. Five weeks later, the pressure was measured. The rat aortas were dyed with Hart's method. The morphometric parameters were calculated by Leica workstation. The plasma level of SO2 was determined by HPLC method. VSMC apoptosis was measured by TUNEL technique. The expression levels of proliferating cell nuclear antigen (PCNA), Bcl-2, Fas and caspase-3 were detected by immunohistochemical assay. RESULTS: (1) Compared with those of the WKY rats, the blood pressure, ratio of media to lumen radius, and proliferation index (PI) of the SHRs were increased [(172 +/- 10) mm Hg vs (112 +/- 9) mm Hg, 0.073 +/- 0.004 vs 0.057 +/- 0.004, 0.32 +/- 0.06 vs 0.05 +/- 0.03, respectively], but the plasma level of SO2 and the apoptosis index (AI) were decreased in the SHRs [(6.4 +/- 1.5) micromol/L vs (11.3 +/- 1.0) micromol/L, 0.16 +/- 0.07 vs 0.30 +/- 0.19, respectively]. The expression of Bcl-2 was increased (0.209 +/- 0.007 vs 0.202 +/- 0.006), and the expression levels of Fas and caspase-3 of SHRs were both lower than those of the WKY rats (0.205 +/- 0.006 vs 0.211 +/- 0.005, 0.229 +/- 0.005 vs 0.244 +/- 0.010, respectively). (2) Compared with the SHR control group, the systolic blood and the ratio of media to lumen radius were decreased [(128 +/- 7) mm Hg, 0.066 +/- 0.002, respectively], but the plasma level of SO2 was increased [(8.3 +/- 1) micromol/L] for the SHR + Na2SO3/NaHSO3 group. PI was lower (0.14 +/- 0.03) and AI was higher (0.40 +/- 0.11) in SHR + Na2SO3/NaHSO3 group than those in SHR control group. The expression of Bcl-2 of VSMCs was down-regulated (0.199 +/- 0.006), but the levels of Fas and caspase-3 were up-regulated (0.218 +/- 0.003 and 0.251 +/- 0.011 respectively) in the SHR + Na2SO3/NaHSO3 group. CONCLUSION: SO2 may attenuate the structural remodeling through reducing the proliferation and enhancing the apoptosis of smooth muscle cells in SHRs. SO2 may modulate the process of apoptosis possibly through the downward regulation of the level of Bcl-2 and enhance the expression of Fas and caspase-3.     

大鼠肝再生过程中肝细胞caspase-3和caspase-8活性的变化

目的:研究大鼠肝再生过程中肝细胞caspase-3和caspase-8活性的变化规律.方法:雄性SD大鼠70%肝切除(PH),制作肝再生模型,制备肝匀浆液,经离心后用酶标仪分别测定肝再生过程中不同时期(共8个时间点),肝细胞的凋亡酶活性.结果:Caspase-3活性,与对照组相比,在PH后3、6、72、120 和168 h时显著性增高(P<0.001);而整个过程中Caspase-8的活性除了在PH后168 h时高于对照组外(P<0.05),其余时间点没有明显增高.结论:肝再生过程中肝细胞凋亡酶Caspase-3活性的升高可能主要是由内源性线粒体途径引起的.     

地佐环平对边缘叶癫痫发作大鼠海马P-糖蛋白表达的影响

目的 观察兴奋性谷氨酸受体（NMDA受体）拮抗剂地佐环平（MK801）对边缘叶癫痫大鼠发作后P-糖蛋白（P—gp）表达的影响,探讨NMDA受体是否能对癫痫发作后P—gp表达进行调控。方法 制备氯化锂．匹罗卡品癫痫发作大鼠模型,60只大鼠,随机分为6组：对照组、癫痫发作终止后0、3、6、24和72h组,用实时荧光定量RT-PCR检测癫痫大鼠发作终止后不同时程海马组织P—gp mRNA的表达。另取60只大鼠随机分为对照组、癫痫持续状态发作模型（SE）组、MK801干预组,各组均分为发作终止后6h和24h时间点。用实时荧光定量RT—PCR检测癫痫发作终止后6h大鼠海马P-gp mRNA的表达,用免疫组化检测大鼠癫痫发作终止后24h海马组织P—gp蛋白的表达。结果 癫痫发作终止后72h内的所有动物海马组织多药耐药基因1a（mdr1a）的表达均显著高于对照组,SE终止即刻其表达显著升高[5．6（2．9）×10^5 mRNA拷贝数／40ng总RNA,P〈0．05],SE终止后3h时其表达进一步升高[7．6（6．3）×10^5,P〈0．01],此后至SE终止后72h,mdrla mRNA的表达一直维持在该水平;mdr1b的表达在边缘叶发作动物呈一过性增高,发作终止后3、6h[分别为（3．3±0．4）×10^4和（3．6±1．0）×10^4,为对照组的2．2、2．4倍]均明显高于对照组（P〈0．01）。另外,在发作终止后6h时,MK801组mdr1a[（4．3±0．8）×10^5]和mdr1b[（2．0±0．7）×10^4]基因表达明显低于SE组（P〈0．01）;发作终止24h时,MK801组P—gp[（26．6±5．0）个微血管／400倍视野]蛋白表达也明显低于SE组[（39．0±4．1）个微血管／400倍视野,P〈0．01]。结论 NMDA受体拮抗剂MK801下调癫痫大鼠发作后P-gp的过度表达,提示NMDA受体可能参与癫痫发作过程中P—gp表达的调控,有效抑制NMDA受体的过度活化可能有助于防止癫痫发作后P—gp的过度表达。     

结缔组织生长因子在血管紧张素Ⅱ诱导的人近端肾小管上皮细胞肥大中的作用

目的　探讨结缔组织生长因子 (CTGF)在介导血管紧张素Ⅱ (AngⅡ )诱导的人肾近端小管细胞肥大中的作用。方法　用 [3 H] 亮氨酸掺入、考马斯亮蓝蛋白质定量技术分别观察抗CTGF抗体对AngⅡ诱导的人肾近端小管上皮细胞株 (HK 2 )细胞内蛋白质从头合成及细胞内蛋白质含量的影响 ;用流式细胞分析技术观察抗CTGF抗体对AngⅡ诱导的细胞周期分布改变的影响 ;用扫描电镜技术观察抗CTGF抗体对AngⅡ诱导细胞形态变化的影响。 结果　AngⅡ可以显著诱导细胞内[3 H] 亮氨酸掺入和细胞内总蛋白质含量增加的作用 ,呈浓度和时间依赖性 ;抗CTGF抗体对AngⅡ诱导的细胞内总蛋白质含量、[3 H] 亮氨酸掺入量的增加有抑制作用 ,呈浓度和时间依赖性。AngⅡ作用于细胞 4 8h后 ,细胞平均直径、G0 G1期细胞百分比显著增加 (均P <0 0 1) ,抗CTGF抗体可显著抑制AngⅡ诱导的细胞直径增加和细胞周期阻滞 (均P <0 0 5或P <0 0 1)。结论　AngⅡ可以诱导肾小管上皮细胞发生肥大 ,CTGF可能介导了AngⅡ诱导的肾小管上皮细胞肥大效应。     

环孢菌素A对体外NIT-1胰岛β细胞增殖及其增殖相关基因表达的影响

目的 观察环孢霉素A(CsA)对体外培养的NIT-1胰岛β细胞增殖和pol αl mRNA表达的影响。方法 用MTT法检测不同浓度的CsA(0．05～10μmol／L)作用48和72h后NIT-1胰岛β细胞增殖的情况。利用半定量RT-PCR法检测10μmol／L CsA处理NIT-1胰岛β细胞48h后pol αl在mRNA水平上的表达。结果 CsA可抑制NIT-1胰岛β细胞的增殖，且与时间、剂量正相关。另外，CsA还下调了pol αl mRNA的表达。结论 CsA可抑制NIT-1胰岛β细胞增殖．其机制可能与下调pol αl mRNA表达有关。     

Serotonin (5-HT1c) receptors in pig choroid plexus.

It is very important to find suitable reaction conditions to attain a high specific binding (specific/total binding) in the receptor binding study. Membrane homogenates of pig choroid plexus are known to have exclusively serotonin (5-hydroxytryptamine, 5-HT) receptor of the subtype 5-HT1c. In this study, we used the membrane preparation of pig choroid plexus tissue and the specific binding of [3H]5-HT was 72-84% to serotonin receptor subtype 5-HT1c, as defined by the inhibition of 1 uM 5-HT, when a radioligand concentration of 0.5 nM of [3H]5-HT was used in the assay. Analysis of the properties of specific [3H]5-HT binding in pig choroid plexus tissue membrane preparation revealed linear Scatchard plots. In Tris-HCl buffer without CaCl2, pargyline or ascorbic acid, high average of affinity dissociation constant (Kd) of 1.3 +/- 0.2 nM (SEM, n = 4) and also a high average of receptor density (Bmax) of 284 +/- 12 fmol/mg of protein were found. Pig choroid plexus proves to be a good material for 5-HT1c receptor binding study.     

大鼠红细胞抗高血压因子的降压作用

本实验表明,从自发性高血压大鼠(SHR)红细胞提取的抗高血压因子(antihyper-tensive factor,AHF)可明显而持久地降低SHR和肾性高血压大鼠(RHR)的血压,而对正常大鼠血压无影响,表明AHF的降压作用与动物原来的血压水平密切相关,即具有血压依赖性;AHF耐热,在沸水中处理15min仍保持其强烈的降压效果,提示其不可能是体内已知的一些舒血管物质。目前,作者正在对AHF的理化特性和降压机理进行更深入的研究。