共查询到19条相似文献,搜索用时 156 毫秒
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兴奋性氨基酸加强高原低氧大鼠下丘脑前生长抑素原mRNA的表达 总被引:5,自引:0,他引:5
目的和方法:应用大鼠高原低氧模型及原位杂交技术和氨基酸测定法,研究下丘脑前生长抑素原(PPS)mRNA表达和谷氨酸(Glu)、天门冬氨酸(Asp)含量的变化。结果:高原低氧组大鼠下丘脑Glu和Asp的含量明显增多,室周核、室旁核、弓状核PPS-mRNA阳性神经元数目显著增加;而NMDA受体拮抗抗剂氯铵酮,虽然对Glu和Asp含量无明显影响,但可使高原低氧大鼠下丘脑PPS-mRNA阳性神经元数目减少 相似文献
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本研究观察了低氧对大鼠肺组织和血管内皮一氧化氮合酶(NOS)活性及内皮衍生一氧化氮(EDNO)依赖性舒张反应的影响,以及NOS抑制剂(L-NAME)对常氧和低氧大鼠肺组织和血管内皮NOS活性及颈、肺动脉血压(CAPs、mPAP)的作用。结果表明常氧大鼠肺泡内无肌性血管内皮未见NOS活性,其肺血管床对EDNO依赖性舒血管物质BK没有反应,注射L-NAME后大鼠mPAP略有降低,CAPs有所升高。低氧大鼠肺泡内无肌性血管内皮显示NOS活性,对BK的EDNO依赖性舒张反应呈剂量依赖性增大,注射L-NAME使低氧大鼠mPAP显著降低(P<0.01),CAPs显著升高(P<0.05)。提示肺血管EDNO及其合酶在维持正常成年大鼠肺循环低压低阻中的生理作用值得进一步探讨;低氧引起肺血管内皮ecNOS活性增加和EDNO生成增多可能起到限制肺动脉压过度升高的调制作用,也可能对肺血管内皮产生毒性作用,反而促进肺动脉高压的发生和发展。 相似文献
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油蒿和籽蒿种子化学组成的研究 总被引:1,自引:0,他引:1
油蒿和籽蒿种子化学组成的研究鲁作民(中国科学院兰州沙漠研究所,兰州730000)STUDIESONCHEMICALCOMPOSITIONSINSEEDSOFARTEMISIAORDOSICAANDA.SPHAEROCEPHALA¥LuZuo-min(... 相似文献
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根田鼠肾上腺皮质酮水平的日节律及急性低氧的影响THECIRCADIANRHYTHMOFCORTICOSTERONELEVELANDEFFECTOFHYPOXIAONROOTVOLE(MICROTUSOECONOMUS)根田鼠(Microtusoec... 相似文献
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17β-雌二醇诱导血管内皮细胞一氧化氮释放及其与细胞内钙的关系 总被引:6,自引:0,他引:6
利用小牛胸主动脉内皮细胞(BAECs)作为模型,观察17β-雌二醇(E2)BAECs一氧化氮(NO)释放、一氧化氮合酶(eNOS)mRNA表达和细胞内钙(〔Ca^2+〕i)的影响,以及雌激素受体(ER)拮抗剂tamoxifen和NOS抑制剂(L-NAME)的作用。结果显示,E2(10^-12 ̄10^-8mol/L)呈尝试依赖性促进BAECs中NO的释放,以10^-8mol/L浓度E2处理BAECs 相似文献
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植物胚胎学实验方法(六)胚和胚乳的解剖和整体制片法 总被引:2,自引:0,他引:2
植物胚胎学实验方法(六)胚和胚乳的解剖和整体制片法胡适宜(北京大学生物系,北京100871)WHOLEMOUNTANDDISSECTINGMETHODSFORTHESTUDYINGOFPLANTEMBRYOSANDENDOSPERMS¥HuShi-y... 相似文献
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根田鼠下丘脑促性腺激素释放激素水平昼夜节律及低氧影响 总被引:2,自引:0,他引:2
根田鼠下丘脑促性腺激素释放激素水平昼夜节律及低氧影响THECIRCADIANRHYTHMOFHYPOTHALAMICGnRHONMICROTUSOECONOMUSANDTHEEFFECTOFHYPOXIA人们早就注意到哺乳动物神经肽、神经递质均有各... 相似文献
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Increased somatostatin mRNA expression in periventricular nucleus of rat hypothalamus during hypoxia
We reported that hypoxia inhibited the growth hormone (GH) and induced somatostatin (SS) release from the hypothalamic median eminence (ME) of rats. This study is designed to examine the SS mRNA alterations in the periventricular nucleus (PeN) of the hypothalamus in rats and the possible involvement of glucocorticoid (GC) during hypoxia. Rats were exposed to hypoxia in a simulated hypobaric chamber. SS mRNA levels in the PeN were tested by in situ hybridization. Hypoxia of 5-km altitude (10.8% O(2)) for 2, 5 and 24 h increased the SS mRNA expression by 34.72%, 50.31% and 95.05% (p<0.05), respectively. Severe hypoxia of 7-km altitude (8.2% O(2)) enhanced the SS expression by 79.08% (p<0.01), 74.90% (p<0.01) and 71.40% (p<0.05), respectively. Prolonged hypoxia (5 km for 5 days) exposure augmented a 2.5-fold SS mRNA (p<0.001). One week post adrenalectomy (ADX), SS mRNA level was significantly increased. During hypoxia, 5 km for 5 h, SS mRNA in ADX rats was not further increased. An increased SS mRNA was showed by pretreatment with low dose of dexamethasone (DEX) (125 microg/kg, i.p.) to ADX animals but this increase was depressed by a high dose of DEX (500 microg/kg, i.p.). The data suggested that (1) hypoxia stimulated the expression of SS mRNA in the PeN of rat hypothalamus. (2) Increased circulating GC levels might play a role in upregulating the SS mRNA in the rat PeN during hypoxia. 相似文献
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L-NAME对大鼠急性脊髓损伤的影响 总被引:2,自引:0,他引:2
实验采用雌性Wistar大鼠15只,分为正常对照组、生理盐水对照组L-NAME治疗组,后两组制成急性脊髓损伤模型,于术后每天一次腹腔注射L-NAME(20kg/kg)或等量生理盐水,连续七天,然后处死动物,行脊髓NOS和Nissl染色。结果显示,L-NAME治疗组脊髓NOS阳性神经元染色较生理盐水对照组浅,组间光密度比较P<0.05。此外,生理盐水对照组脊髓神经元还出现尼氏体位、减少,甚至消失等现象;这些改变在L-NAME治疗组较轻,因此我们认为,大鼠急性脊髓损伤可诱导神经元NOS表达,L-NAME可对其损伤修复起促进作用。 相似文献
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Chronic pain is associated with N-methyl-D-aspartate (NMDA) receptor activation and downstream production of nitric oxide, which has a pivotal role in multisynaptic
local circuit nociceptive processing in the spinal cord. The formation of nitric oxide is catalyzed by three major nitric
oxide synthase (NOS) isoforms (neuronal, nNOS; inducible, iNOS; endothelial, eNOS), which are increased in the spinal cord
of rodents subjected to some tonic and chronic forms of experimental pain. Despite the important role of NOS in spinal cord
nociceptive transmission, there have been no studies exploring the effect of NMDA receptor blockade on NOS expression in the
dorsal horn during chronic pain. Furthermore, NOS isoforms have not been fully characterized in the dorsal horn of animals
subjected to arthritic pain. The aim of this work was therefore to study the expression of nNOS, iNOS and eNOS in the dorsal
horns of monoarthritic rats, and the modifications in NOS expression induced by pharmacological blockade of spinal cord NMDA
receptors. Monoarthritis was produced by intra-articular injection of complete Freund's adjuvant into the right tibio-tarsal
joint. At week 4, monoarthritic rats were given either the competitive NMDA antagonist (±)-3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic
acid (CPP) or the uncompetitive NMDA antagonist ketamine. After 6 and 24 hours, animals were killed and posterior quadrants
of the lumbar spinal cord were dissected. Sample tissues were homogenized and subjected to immunoblotting with anti-nNOS,
anti-iNOS or anti-eNOS monoclonal antibodies. The nNOS isoform, but not the iNOS and eNOS isoforms, were detected in the dorsal
horns of control rats. Monoarthritis increased the expression of nNOS, iNOS and eNOS in the dorsal horns ipsilateral and contralateral
to the inflamed hindpaw. Intrathecal administration of CPP and ketamine reduced nNOS expression in monoarthritic rats but
increased the expression of iNOS and eNOS. Results suggest that blockade of spinal cord NMDA receptors produces complex regulatory
changes in the expression of NOS isoforms in monoarthritic rats that may be relevant for nitridergic neuronal/glial mechanisms
involved in the pathophysiology of monoarthritis and in the pharmacological response to drugs interacting with NMDA receptors. 相似文献
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间断低氧对大鼠下丘脑超微结构及前增食欲素水平的影响 总被引:1,自引:0,他引:1
目的探讨睡眠中间断低氧对大鼠下丘脑前增食欲素及受体水平的影响以及下丘脑超微结构的变化。方法大鼠分成对照组、间断低氧组和持续低氧组,分别给予吸入空气,持续低氧和间断低氧气体,并在实验开始后1d、3d、1w和4w应用RT-PCR方法测定大鼠下丘脑前增食欲素及受体水平,分析其间的变化关系,电镜观察下丘脑的超微结构变化。结果与对照组和持续低氧组比较,间断低氧4w后大鼠下丘脑前增食欲素mRNA水平明显降低,受体水平升高,但在持续低氧和对照组之间无明显差异。在低氧后1d、3d、7d后大鼠下丘脑前增食欲素mRNA降低,受体水平升高,在4w后,持续低氧组则接近正常。急性持续低氧大鼠超微结构变化更严重,而慢性间断低氧变化更持久。结论慢性间断低氧可以引起下丘脑前增食欲素下降及受体水平升高,急性持续低氧也可引起上述变化,而慢性持续低氧未引起增食欲素改变;慢性间断低氧大鼠下丘脑超微结构表现为严重而持久的变化。 相似文献
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Hemodilutional anemia is associated with increased cerebral neuronal nitric oxide synthase gene expression. 总被引:3,自引:0,他引:3
Gregory M T Hare C David Mazer William Mak Reginald M Gorczynski Kathryn M Hum Steve Y Kim Leslie Wyard Aiala Barr Rong Qu Andrew J Baker 《Journal of applied physiology》2003,94(5):2058-2067
Severe hemodilutional anemia may reduce cerebral oxygen delivery, resulting in cerebral tissue hypoxia. Increased nitric oxide synthase (NOS) expression has been identified following cerebral hypoxia and may contribute to the compensatory increase in cerebral blood flow (CBF) observed after hypoxia and anemia. However, changes in cerebral NOS gene expression have not been reported after acute anemia. This study tests the hypothesis that acute hemodilutional anemia causes cerebral tissue hypoxia, triggering changes in cerebral NOS gene expression. Anesthetized rats underwent hemodilution when 30 ml/kg of blood were exchanged with pentastarch, resulting in a final hemoglobin concentration of 51.0 +/- 1.2 g/l (n = 7 rats). Caudate tissue oxygen tension (Pbr(O(2))) decreased transiently from 17.3 +/- 4.1 to 14.4 +/- 4.1 Torr (P < 0.05), before returning to baseline after approximately 20 min. An increase in CBF may have contributed to restoring Pbr(O(2)) by improving cerebral tissue oxygen delivery. An increase in neuronal NOS (nNOS) mRNA was detected by RT-PCR in the cerebral cortex of anemic rats after 3 h (P < 0.05, n = 5). A similar response was observed after exposure to hypoxia. By contrast, no increases in mRNA for endothelial NOS or interleukin-1beta were observed after anemia or hypoxia. Hemodilutional anemia caused an acute reduction in Pbr(O(2)) and an increase in cerebral cortical nNOS mRNA, supporting a role for nNOS in the physiological response to acute anemia. 相似文献
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低压低氧对胎鼠海马神经元NMDA受体影响的实验研究 总被引:1,自引:0,他引:1
目的:观察低压低氧环境对胎鼠海马神经元NMDA受体数目和通道特性的影响。方法:采用原位杂交和膜片钳观察NMDA受体的数量和功能。结果:胎鼠低压低氧后,NMDA受体数量和通道开放机率减少,通道开放时间常数减少,通道关闭时间常数增加。结论:低压低氧影响到胎鼠NMDA受体的发育,提示低压低氧环境下大鼠的学习记忆可能受到影响。 相似文献
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Faucard R Armand V Héron A Cochois V Schwartz JC Arrang JM 《Journal of neurochemistry》2006,98(5):1487-1496
The modulation of histamine neuron activity by various non-competitive NMDA-receptor antagonists was evaluated by changes in tele-methylhistamine (t-MeHA) levels and histidine decarboxylase (hdc) mRNA expression induced in rodent brain. The NMDA open-channel blockers phencyclidine (PCP) and MK-801 enhanced t-MeHA levels in mouse brain by 50-60%. Ifenprodil, which interacts with polyamine sites of NR2B-containing NMDA receptors, had no effect. PCP also increased hdc mRNA expression in the rat tuberomammillary nucleus. The enhancement of t-MeHA levels elicited by MK-801 (ED50 of approximately 0.1 mg/kg) was observed in the hypothalamus, cerebral cortex, striatum and hippocampus. Control t-MeHA levels and the t-MeHA response to MK-801 were not different in male and female mice. Double immunostaining for HDC and NMDA receptor subunits showed that histamine neurons of the rat tuberomammillary nucleus express NMDA receptor subunit 1 (NR1) with NMDA receptor subunit 2A (NR2A) and NMDA receptor 2B subunit (NR2B). In addition, immunoreactivity for the neuronal glutamate transporter EAAC1 was observed near most histaminergic perikarya. Hence, these findings support the existence of histamine/glutamate functional interactions in the brain. The increase in histamine neuron activity induced by NMDA receptor antagonists further suggests a role of histamine neurons in psychotic disorders. In addition, the decrease in MK-801-induced hyperlocomotion observed in mice after administration of ciproxifan further strengthens the potential interest of H3-receptor antagonist/inverse agonists for the symptomatic treatment of schizophrenia. 相似文献