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1.
文和群   《广西植物》1995,15(3):212-213
多叶猴耳环──猴耳环属一新种文和群(广西植物研究所分类研究室,桂林541006)PITHECELLOBIUMMULTIFOLIOLATUM-ANEWSPECIESOFPITHECELLOBIUMFROMGUANGXI,CHINAWenHequn(Gu...  相似文献   

2.
"植物抗寒剂"新、陈药对早稻育秧效果的比较李志高(湖北省洪湖市农科所,433200)ACOMPARISONBETWEENTHEEFFCTSOFTHENEWPRODUCTSANDOLDPRODUCTSOFTHECOLD-RESISTERAPPLIEDT...  相似文献   

3.
P~(53) PROTEIN OVEREXPRESSION IN PREMALIGNANT AND MALIGNANT LESIONS OF ORAL MUCOSA:IMMUNOHISTOCHEMICAL OBSERVATIONP~(53)PROTEI...  相似文献   

4.
LI┐6400光合作用测定系统:原理、性能、基本操作与常见故障的排除蒋高明(中国科学院植物研究所,北京100093)LI—6400PORTABLEPHOTOSYNTHESESSYSTEM:PRINCIPLE,FUNCTION,BASICOPERATI...  相似文献   

5.
本文研究了实验性在醇血症大鼠肝脏低密度脂蛋白受体(LDL-R)活性变化及有氧运动时LDL-R活性调节的影响,发现,高脂(HC)组肝组织匀浆LDL-RI自古以来生较正常对照(NC)组降低37%(P〈0.05),同时血清大醇(TC)、低密度脂收白胆固醇(LDL-C)及血清栽脂蛋白B(ApoB)均显著高于NC组(P〈0.01);高脂+运动(HE)组TC、LDL-C及ApoB均明显低于HC组,而LDL-R  相似文献   

6.
人GM—CSF cDNA的克隆和在大肠杆菌中的表达   总被引:3,自引:0,他引:3  
从诱导的人胚肺细胞HFL株中提取总RNA.经RT-PCR反应获取了人GM-CSFcDNA,DNA序列测定表明其顺序与文献报道完全一致。为了获得高效表达,应用PCR改造了人GM-CSF的cDNA5’端核苷酸序列,并将改造的人GM-CSF基因插入含T7启动子的质粒pET-11d构建成表达质粒pETC-5,将此质粒转化大肠杆菌株BL21(DE3)得到表达菌株BLEC4。表达菌株用0.5mol/LIPTG诱导2小时后,产生大量重组蛋白并形成包涵体。SDS—PAGE电泳图谱扫描结果表明,rhGM-CSF产量占菌体总蛋白量的16%。ELISA和TF-1细胞培养测定表明,初步纯化和复性的rhGM-CSF具有天然的hGM-CSF生物活性。  相似文献   

7.
关于紫菜生活史的讨论   总被引:1,自引:0,他引:1  
钟恒 《植物学通报》1996,13(3):62-64
关于紫菜生活史的讨论钟恒(中山大学生物系,广州510275)NOTESONTHELIFECYCLEOFPORPHYRAZhongHeng(DepartmentofBiology,ZhongshanUniversity,Guangzhou510275)...  相似文献   

8.
目的:探讨人脐带清(CBS)在骨髓造血祖细胞培养中的效应。方法:用人骨髓细胞进行CFU、GM、VFU-E、BFU-E、CFU-GEMM培养。结果:CBS能直接刺激骨髓细胞CEU-GM的形成。与血型相同害无关。四人份以上的混合CBS(MCBS),刺激活性高且稳定。10%MCBS相当于65.6μg/L GM-CSF、0.23、0.3、0。.46kU/L EpO对CFU-GM、CFU-E、BFU-E、C  相似文献   

9.
胃粘膜血流量对大鼠胃粘膜适应性细胞保护作用的影响   总被引:14,自引:2,他引:12  
阎长栋  顾洛 《生理学报》1996,48(5):469-476
采用氢气清除法测定胃粘膜血流量,观察大鼠胃内灌洗低浓度盐酸酒精后灌注高浓度盐酸酒精(0.6mol/LHCl+15%EtOH)对GMBF和胃粘膜损害的影响。以及GMBF在适应性细胞保护中的作用。结果如下:(1)先用低浓度盐酸酒精作为弱刺激灌注随之以高浓度盐酸酒精作为强刺激灌注,引起胃粘膜适应性保护现象,它表现为:大体操作和损伤深度分别比单独泊组减少47.09%和44.57%应性现象,它表现为:大体损  相似文献   

10.
非诱导光周期对植物开花的抑制作用范国强*谭克辉(中国科学院植物研究所,北京,100093)INHIBTORYEFFECTOFNON┐INDUCEDPHOTO┐PERIODONPLANTFLOWERINGFanGuo-qiangTanKe-hui(I...  相似文献   

11.
目的 :探讨一氧化氮和内皮素在急性乙醇胃粘膜损伤中的作用及其相互关系。方法 :采用大鼠乙醇胃粘膜损伤模型 ,测定其胃粘膜内一氧化氮合成酶 (NOS)和内皮素 (ET)含量并观察其胃粘膜病理变化。结果 :随着乙醇作用时间延长和胃粘膜损伤的加重 ,胃粘膜内ET含量显著上升 (P <0 .0 5 ) ,而NOS的含量显著下降 (P <0 .0 5 ) ,两者呈负相关。结论 :胃粘膜内ET释放增加和NOS活性下降参与了急性乙醇胃粘膜损伤的病理生理过程。  相似文献   

12.
目的: 研究一氧化氮(NO)和内皮素-1(ET-1)在大鼠肢体缺血/再灌注(LI/R)后脑损伤中的作用,探讨NO/ET-1平衡关系的变化对脑损伤的影响.方法: 在大鼠LI/R损伤模型上,应用NO合成前体物质L-精氨酸(L-Arg)、一氧化氮合酶(NOS)抑制剂氨基胍(AG)、ETA受体阻断剂BQl23进行干预,观察血浆 NO、ET-1、MDA、XOD、SOD、LDH及脑组织tNOS、iNOS、cNOS、NO、ET-1、MDA、XOD、MPO、 SOD的变化.结果: 与对照组比较,I/R组血浆MDA、XOD、LDH及脑组织MDA、XOD、MPO升高,SOD活性降低(P<0.01),脑组织tNOS和iNOS明显升高,而cNOS明显降低(P<0.01),I/R组血浆及脑组织NO、ET-1增加,NO/ET-1比值降低,脑损伤加重.应用L-Arg及BQ123后,血浆及脑组织NO/ET-1比值较I/R组升高,脑损伤减轻,应用AG后,NO/ET-1比值降低,脑损伤进一步加重.结论: 肢体缺血/再灌注后,一氧化氮与内皮素-l的比值降低时脑损伤加重.  相似文献   

13.
缺血预适应对大鼠肢体缺血/再灌注后肺损伤的影响   总被引:2,自引:0,他引:2  
目的:观察肢体缺血预适应对大鼠肢体缺血/再灌注(I/R)后肺损伤的影响并探讨其机制。方法:将雄性Wistar大鼠随机分为4组(n=8):对照组(C),肢体缺血/再灌注组(LI/R),缺血预适应组(IPC)和L-NAME组。各组大鼠均于肢体缺血4h再灌注4h处死,分别测定其动脉血氧分压(PaO2)和二氧化碳分压(PaCO2),血浆及肺组织丙二醛(MDA)、一氧化氮(NO)、内皮素(ET)含量,计算血浆NO/ET比值;以及肺湿干比(W/D)、肺系数(LI),肺组织髓过氧化物酶(MPO)含量。结果:大鼠LI/R后4h,PaO2明显降低;W/D、LI、血浆及肺组织的MDA、NO、ET和肺组织MPO活性均明显增加,而血浆NO/ET比值明显减小。与LI/R组比较,IPC组各项损伤指标明显减轻,NO水平升高,血浆NO/ET比值明显增大。与对照组和IPC组比较,L-NAME处理组,各项损伤指标数值明显增加,NO水平降低;血浆NO/ET比值明显减小,差异均具有显著性。各组大鼠PaCO2的变化无显著性。结论:缺血预适应对肢体缺血/再灌注后肺损伤具有保护作用,其机制可能与内源性NO合成增加有关。  相似文献   

14.
The aim of this study was to investigate the mechanisms involved in the effect of glucagon-like peptide-1 (GLP-1) on the decrease in gastric mucosal blood flow (GMBF) induced by intragastric ethanol.After preparation of the stomach for GMBF recording, a probe was placed to the gastric mucosa and basal GMBF recordings were obtained by a laser Doppler flowmeter after a 30-minute stabilization period. Following GLP-1 (1000 ng/kg; i.p.) injection, 1 ml of absolute ethanol was applied to the gastric chamber and GMBF was recorded continuously during a 30-minute period. GLP-1 (1000 ng/kg; i.p.) prevented the decrease in GMBF induced by ethanol. Nitric oxide (NO) synthase inhibitor L-NAME, (30 mg/kg; s.c.), calcitonine gene-related peptide (CGRP) receptor antagonist CGRP-(8–37) (10μg/kg; i.p.), and cyclooxygenase inhibitor indomethacin (5 mg/kg; i.p.) all inhibited the GMBF-improving effect of GLP-1.We concluded that, NO, CGRP and prostaglandins may be involved in the effect of peripherally-injected GLP-1 on GMBF reduction induced by intraluminal ethanol.  相似文献   

15.
The aim of the present study was to examine the effect of alpha and beta adrenoceptor blockade on gastric acid secretion, mucosal blood flow (GMBF) and catecholamine content of the gastric mucosa during glucagon-induced inhibition of gastric acid secretion. The secretory response to continuous infusion of pentagastrin (6 micrograms/kg/h) was reduced by regitine (0.5 mg/kg/h) and propranolol (25 micrograms/kg/h). Glucagon (25 ng/kg/h) further slightly decreased HCl secretion. GMBF was also significantly inhibited by regitine and propranolol. Administration of glucagon continued decreasing of the GMBF. By determining the change in the ratio of blood flow to secretory rate, this reduction in mucosal blood flow was found to be secondary to a fall in secretion. In these studies a concomitant increase in noradrenaline content of the gastric mucosa was observed: after regitine by 50%, after propranolol--by 32.5%, after these blockers given simultaneously--by 75%. The level of noradrenaline was higher after subsequent administration of glucagon. Our results indicate that more than one component is responsible for the inhibitory effect of glucagon on pentagastrin-stimulated gastric acid secretion.  相似文献   

16.
Receptor-activating peptides for protease-activated receptors (PARs) 1 or 2 enhance gastric mucosal blood flow (GMBF) and protect against gastric mucosal injury in rats. We thus examined and characterized the effects of PAR-1 and PAR-2 agonists on the isometric tension in isolated rat gastric artery. The agonists for PAR-2 or PAR-1 produced vasodilation in the endothelium-intact arterial rings, which was abolished by removal of the endothelium. The mechanisms underlying the PAR-2- and PAR-1-mediated relaxation involved NO, endothelium-derived hyperpolarizing factor (EDHF) and prostanoids, to distinct extent, as evaluated by use of inhibitors of NO synthase, cyclo-oxygenase and Ca2+-activated K+ channels. The EDHF-dependent relaxation responses were significantly attenuated by gap junction inhibitors. These findings demonstrate that endothelial PAR-1 and PAR-2, upon activation, dilate the gastric artery via NO and prostanoid formation and also EDHF mechanisms including gap junctions, which would enhance GMBF.  相似文献   

17.
乙醇对胃粘膜的损伤及牛磺酸的保护作用   总被引:5,自引:1,他引:4  
Xie Y  Li XP  Wang CW  Huang DQ  Zhu JQ  Zhang KH  Chen J 《生理学报》1999,51(3):310-314
为了探讨乙醇性胃粘膜损伤和牛磺酸对其保护作用的机制,将40只SD大鼠分为对照组、乙醇损伤组和牛磺酸保护组,观察其胃粘膜中内皮素(ET)、一氧化氮合成酶(NOS)、生长抑素(SS)和血管活性肠肽(VIP)的变化。结果如下:(1)随着乙醇作用时间延长、粘膜的损伤加重,胃粘膜内ET含量显著上升,而NOS、SS和VIP含量显著下降;(2)牛磺酸可显著减轻乙醇性胃粘膜损伤,抑制ET释放,增加NOS活性和SS、VIP的含量。上述结果表示,ET、NOS、SS和VIP的变化参与了乙醇性胃粘膜损伤的病理生理过程;牛磺酸对乙醇性胃粘膜损伤具有保护作用,可能与其调节胃粘膜内ET、NOS、SS和VIP的释放与活性有关。  相似文献   

18.
Tashima K  Fujita A  Umeda M  Takeuchi K 《Life sciences》2000,67(13):1639-1652
We compared the gastric toxic effect of aspirin (ASA) in both normal and diabetic rats, with that of NCX-4016, a derivative of ASA with nitric oxide (NO) releasing moiety. Animals were injected with streptozotocin and used after 5 weeks of diabetes with blood glucose levels of >350 mg/dl in the presence of omeprazole. Oral administration of ASA (with 150 mM HCl) did not produce damage at 30 mg/kg in the conscious rat but caused hemorrhagic gastric lesions in STZ-diabetic rats. By contrast, NCX-4016 even at 190 mg/kg (a dose equimolar to 100 mg/kg of ASA) did not cause damage in both normal and STZ-diabetic rat stomachs. Plasma salicylic acid levels were not different between normal and diabetic rats after administration of ASA or NCX-4016, though the latter gave significantly lower levels as compared to ASA. Intragastric application of ASA (80 mM in 50 mM HCl) for 30 min caused a reduction of transmucosal PD and increase of luminal H+ loss with a minimal effect on mucosal blood flow (GMBF) in both normal and diabetic rats, yet resulting in much severe damage in the stomach of the latter group. Mucosal application of NCX-4016, however, did not cause PD reduction and luminal H+ loss, but produced a marked hyperemia, resulting in no damage in the stomach of both normal and STZ-diabetic rats. The increased gastric toxicity of ASA in STZ-diabetic rats was significantly mitigated by co-application of a NO donor FK-409 together with ASA, with an increase of GMBF, despite similar degrees of PD reduction and luminal H+ loss being observed. We conclude that NCX-4016 does not have a toxic effect in either normal or diabetic rat stomachs, although the diabetic rat stomach is more vulnerable to ASA-induced damage. NCX-4016, though absorbed more slowly than ASA, counteracts the injurious effect of aspirin on the gastric mucosa, probably by increasing GMBF mediated by NO.  相似文献   

19.
BACKGROUND--AIMS:The mechanisms of somatostatin-mediated gastroprotection are not fully understood. Aims of this study were to determine in the rat the role of nitric oxide (NO) in somatostatin-induced effects on gastric mucosal protection and blood flow (GMBF) in the absence and in the presence of intraluminal ethanol. METHODS: Ethanol (70% v/v)-induced gastric mucosal injury after orogastric dosing was quantitated at 30 min and GMBF determined in an ex vivo gastric chamber preparation. RESULTS: Somatostatin (4 microg/kg; i.p.) protection against ethanol-induced ulceration was prevented by the NO inhibitor L-NNA and restored by L-arginine, but not D-arginine. Somatostatin (1-8 microg/kg; i.p.) did not effect basal GMBF. The gastroprotective dose of somatostatin (4 microg/kg; i.p.) prevented the decrease in GMBF caused by ethanol. L-NNA reversed this vascular effect of somatostatin. CONCLUSION: Somatostatin-induced gastroprotection and restoration of GMBF during ethanol exposure involve mechanisms which are dependent on NO generation.  相似文献   

20.
将Wistar大鼠暴露于3 780 m低氧环境,分别于24 h、2 wk及3 wk后采用酶联免疫法和硝酸还原酶法测定血液中的ET~(-1)和NO的含量,计算NO/ET~(-1)值,并与高原鼠兔比较,探讨低氧条件下大鼠与高原鼠兔血液中NO与ET~(-1)含量的变化趋势。结果表明,低氧24 h后,大鼠血液中NO和ET~(-1)的含量显著高于同海拔的高原鼠兔(P<0·01),而NO/ET~(-1)值无显著差异(P>0·05)。随着大鼠在高海拔停留时间的延长,血液中NO含量呈减少趋势,而ET~(-1)则有上升趋势,二者呈显著的负相关(r2=0·2416,P<0·01)。高原鼠兔NO/ET~(-1)值约为大鼠低氧2 wk和3 wk的2倍(P<0·01)。说明不同低氧暴露时间,高原鼠兔和大鼠的NO、ET~(-1)及NO/ET~(-1)值有显著差异,提示NO/ET~(-1)值可以作为有机体是否适应高原低氧环境的一个指标。  相似文献   

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