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完整後設資料紀錄
DC 欄位 | 值 | 語言 |
---|---|---|
dc.contributor.advisor | 蘇銘嘉(Ming-Jai Su) | |
dc.contributor.author | Ching-Chia Chang Chien | en |
dc.contributor.author | 張簡敬家 | zh_TW |
dc.date.accessioned | 2021-05-14T17:47:27Z | - |
dc.date.available | 2016-02-24 | |
dc.date.available | 2021-05-14T17:47:27Z | - |
dc.date.copyright | 2016-02-24 | |
dc.date.issued | 2015 | |
dc.date.submitted | 2015-09-27 | |
dc.identifier.uri | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/4797 | - |
dc.description.abstract | 實驗背景:
血清素為一內生性之單胺,其受體包含有十四種亞型。多樣並廣泛分布的受器讓血清素在中樞神經系統及周邊組織參與許多生理調控及病理發展,因此近年來許多研究以血清素及血清素受器為標的來發展治療藥物。血清素受器第二甲型(5-HT2A)表現在血小板及各種血管組織平滑肌細胞上,而活化此受器可以促進血小板活化、凝集,病誘發血管收縮。在人類冠狀動脈上,活化此亞型之血清素受器可誘發冠狀動脈收縮,因此已有許多此亞型受器之拮抗劑被開發為冠狀動脈疾病之治療藥物。然而在人類冠狀動脈血管上,血清素亦可以引發血管放鬆,此現象在大鼠、狗、豬…等實驗動物也曾被報導過,但其機轉卻甚少人探討。在目前有限的研究中,第七型(5-HT7)及第一乙型(5-HT1B)的血清素受器被認為可能是媒介血清素誘發狗冠狀動脈放鬆的受器亞型,但在其他動物包括人的冠狀動脈上血清素是經由何種亞型的受器誘發冠狀動脈放鬆則沒有人報導過。在過去大部分的研究認為血清素是經由活化位於內皮細胞上的血清素受器誘發內皮細胞釋放一氧化氮來引發血管平滑肌放鬆,但也有研究報告認為血清素可能是經由誘發內皮細胞釋放前列環素(prostacyclin, PGI2)來造成血管放鬆,而在本實驗室過去的研究發現血清素可能可以經由一氧化氮以外的途徑造成大鼠的冠狀動脈放鬆。內皮源過極化因子(endothelium-derived hyperpolarizing factor, EDHF)是一內皮釋放之血管放鬆因子,其經由誘發血管平滑肌過極化(hyperpolarization)來抑制血管的收縮反應。目前內皮源過極化因子的真實身分還沒有被確認,但是鈣離子活化鉀離子通道(Ca2+-activated K+ channels)被認為參與內皮源過極化因子誘發血管放鬆之反應,而此鈣離子活化鉀離子通道之活化被認為可能與細胞色素脢P450s (cytochrome P450s)之代謝物有關。 八苯基異喹林化合物為台大藥學系忻凌偉所開發合成之系列化合物,其對血清素受器第二甲型及第七型有很高的親和力及選擇性,但其藥理性質目前還不清楚。 吾人認為研究血清素對冠狀動脈的放鬆作用之機轉及八苯基異喹林化合物之藥理特性或許能提供冠狀動脈疾病及其他血清素受器調節劑之開發提供一新的研究方向。 實驗方法: 本研究以定壓灌流並固定心跳速度的離體灌流的大鼠心臟為研究模式,以觀察在各種藥理工具存在下血清素誘發之灌流速度變化是否不同來評估第七型受器以及內皮源過極化因子是否參與血清素誘發之冠狀動脈放鬆。此外並經由觀察八苯基異喹林系列化合物血清素誘發離體大鼠去內皮胸腔大動脈收縮反應的影響,以及利用大鼠富含血小板血漿(platelet-rich plasma)來觀察八苯基異喹林系列化合物對血清素增強膠原蛋白(collagen)誘發血小板凝集的作用來評估八苯基異喹林系列化合物對血清素第二甲型受器的作用。 八苯基異喹林中對第二甲型及第七型血清素受器有最高親和力的化合物CYY054C被挑選出來作進一步測試。其中利用前述離體灌流大鼠心臟模式來評估CYY054C對第七型血清素受器之作用,並且利用在麻醉大鼠靜脈射血清素觀察血壓變化的模式來評估CYY054C在活體上對血清素第二甲型及第七型受器的作用。最後則利用內毒素(endotoxin,lipopolysaccharide,LPS)腹腔注射誘發敗血症小鼠的模式來評估CYY054C對敗血症之保護效果。 實驗結果: 血清素引發之灌流速度增加可被第七型受器抑制劑SB269970及TCW295所抑制。一氧化氮合成脢(nitric oxide synthase, NOS)抑制劑L-NAME無法完全抑制血清素引發之冠狀動脈灌流速度增加。在L-NAME存在下,血清素引發之冠狀動脈灌流速度增加可以被甲二型磷酯質酯解脢(phospholipase A2, PLA2)之抑制劑 quinacrine及細胞色素脢抑制劑SKF525A所抑制,但花生烯酸環氧合脢抑制劑indomethacin則沒有明顯影響。中流量(intermediate-conductance)鈣離子活化鉀離子通道抑制劑TRAM-34、小流量(small-conductance) 鈣離子活化鉀離子通道抑制劑UCL1684,以及大流量 (large-conductance) 鈣離子活化鉀離子通道抑制劑TEA在L-NAME存在下可抑制血清素誘發之冠狀動脈灌流增加,但另二個大流量鈣離子活化鉀離子通道抑制劑paxilline及penitrem A則無明顯作用。在幾個初步測試中,TEA對小流量及中流量(intermediate-conductance)鈣離子活化鉀離子通道活化劑SKA-31誘發之冠狀動脈灌流速度增加並沒有抑制的作用,而大流量鈣離子活化鉀離子通道活化劑BMS191011在L-NAME存在下對冠狀動脈沒有明顯的作用;另一個大流量鈣離子活化鉀離子通道活化劑NS1619在L-NAME存在下可明顯誘發冠狀動脈灌流速度增加,但此作用並不受到TEA及paxilline的干擾。 在血清素引發離體大鼠去內皮胸腔大動脈收縮的實驗中,八苯基異喹林系列化合物對此血清素誘發的收縮反應有不同程度的抑制作用,其中以CYY054C的抑制效果強。在膠原蛋白誘發血小板凝集的實驗中,CYY050C及CYY054C能明顯抑制血清素引發的增強效果。在離體灌流心臟上,CYY054C並不會引發明顯的冠狀動脈灌流速度增加,但是可以抑制血清素第七型受器活化劑5-CT所引發的冠狀動脈流速增加。在血清素第七型受器拮抗劑SB269970處理的麻醉大鼠,靜脈投與CYY054C可以抑制靜脈注射血清素引發的血壓上升,但此抑制效果略遜於另一血清素第二甲型受器拮抗劑R96544;在R96544處理的麻醉大鼠,靜脈投與CYY054C可以抑制靜脈注射血清素引發的低血壓反應,但此抑制效果略遜於另一血清素第七型受器拮抗劑SB269970。在腹腔注射內毒素誘發敗血症的小鼠上,於內毒素注射後第12小時開始每六小時腹腔投與CYY054C 300 μg/kg 至內毒素注射後第48小時,可減少內毒素注射後三天的死亡率。 討論: 由實驗結果可知於大鼠冠狀動脈血清素可經由活化第七型受器來誘發血管放鬆,而此血管放鬆作用含有釋放NO以外的機制,且此機制與目前對於內皮源過極化因子的知識相吻合。 八苯基異喹林化合物皆具有血清素二甲型受器拮抗劑之作用,其中以CYY054C作用最強。CYY054C對血清素第七型受器有很強的拮抗作用,但沒有明顯的活化作用。CYY054C對血清素受器第二甲型及第七型的拮抗效果也可在活體上觀察到,但其效果略遜於市面上的拮抗劑R96544及SB269970。CYY054C對於內毒素誘發之敗血症可能有保護作用,但此保護效果與血清素受器之關連還不清楚。 結論: 血清素經由活化第七型受器引發大鼠冠狀動脈放鬆,此作用可能與釋放一氧化氮及內皮源過極化因子有關。CYY054C對血清素第二甲型及第七型受器有很好的拮抗作用,並可能對敗血症有治療效果,但其中的機轉仍待進一步研究。 | zh_TW |
dc.description.abstract | Background:
Serotonin-induced coronary artery responses have both vasoconstriction and vasorelaxation components. The vasoconstrictive effects of serotonin have been well studied while the mechanism(s) of how serotonin causes relaxation of coronary arteries has been less investigated. In dogs, serotonin-induced relaxation of coronary arteries is mediated by 5-HT7 and/or 5-HT1B receptor, and both endothelium- dependent and endothelium-independent serotonin-induced vasorelaxations have ben reported. In human and rats, the subtype(s) of seorotonin receptor mediating the vasorelaxation has not been reported; in rats, the vasorelaxation induced by serotonin has been reported endothelium-dependent and nitric oxide (NO)-dependent, but NO-independent mechanism ha also bee reported, too. Endothelium-derived hyperpolarizing factor (EDHF) is an endothelium-released vasorelaxant, it dilates vessels by inducing the hyperpolarization of membrane potential on smooth muscle cells and hence preventing the influx of calcium. So far, there is no conclusion on what the entity of EDHF is, but the involvement of Ca2+-activated K+ channels has been recognized. EDHF has been reported involved in the serotonin-induced hypotension, but the role of EDHF in serotonin-induced coronary responses has not been studied. The 8-phenylisoquinoline derivatives used in the present dissertation are designed and synthesized by Prof. Ling-Wei Hsin. These compounds have high affinities and selectivities to 5-HT2A and 5-HT7 receptors, but their pharmacological properties have not been fully studied. Methods: Effects of serotonin on coronary arteries were evaluated on isolated perfused rat hearts which were paced constantly and perfused at constant pressure. The roles of different subtypes of serotonin receptor and EDHF in the serotonin-induced coronary responses were evaluated by observing the effects of various pharmacological tools on the serotonin-induced coronary flow alteration. The pharmacological properties of 8-pheylisoquinoline derivatives on 5-HT2A receptor were evaluated by observing their effects on serotonin-induced vasoconstriction of isolated de-endothelium rat thoracic aorta and serotonin-induced amplification of collagen-induced platelet aggregation in rat platelet-rich plasma. Furthermore, the effects of CYY054C, which has the highest affinity to 5-HT2A and 5-HT7 receptor among these compounds, on coronary flow of isolated rat heart was tested in order to evaluate its effect on 5-HT7 receptor; effects of CYY054C on serotonin-injection induced blood pressure alterations were tested, and the effect of CYY054C on the survival rate of lipopolysaccharide (LPS)-induced septic mice was evaluated. Results: Serotonin (0.3 and 1 μM) increased coronary flow on isolated rat hearts, and treatment of nitric oxide synthase inhibitor Nω-nitro-L-arginine methyl ester (L-NAME) 300 μM reduced but not totally blocked this coronary flow increasing effect. In L-NAME 10 μM treated heart, treatment of selective serotonin 5-HT7 receptor antagonist SB269970 0.1 μM blocked serotonin induced coronary flow increasing response, and in the presence of 1 μM SB269970, serotonin turned into reducing coronary flow. Treatment of TCW295, a novel serotonin 5-HT2A/7 receptor antagonist, inhibited both serotonin induced coronary flow increasing and decreasing effects. Serotonin and the 5-HT7 receptor agonist 5-carboxamidotryptamine induced coronary flow increases in the absence of L-NAME, and both of these effects were blocked by the selective 5-HT7 receptor antagonist SB269970; in SB269970-treated hearts, serotonin induced coronary flow decreases, which effect was blocked by the 5-HT2A receptor blocker R96544. In L-NAME-treated hearts, serotonin-induced coronary flow increases were blocked by the phospholipase A2 inhibitor quinacrine and the cytochrome P450s inhibitor SKF525A, but were not inhibited by the cyclooxygenase inhibitor indomethacin. As to the effects of the Ca2+-activated K+ channel blockers, serotonin-induced coronary flow increases in L-NAME-treated hearts were inhibited by TRAM-34 (intermediate-conductance Ca2+-activated K+ channel blocker) and UCL1684 (small-conductance Ca2+-activated K+ channel blocker), but effects of the large-conductance Ca2+-activated K+ channel blockers on 5-HT- induced coronary flow increases were various: penitrem A and paxilline did not significantly affect 5-HT-induced coronary flow responses while tetraethylammonium suppressed the coronary flow increases elicited by serotonin. The 8-pheylisouinoline derivatives inhibited serotonin-induced vasoconstriction and serotonin-induced amplification of collagen-induced platelet aggregation at different potency, and among these compounds CYY054C exhibited the most potent inhibitory effect. CYY054C did not significantly induced coronary flow increases on isolated rat hearts, but inhibited the coronary flow increases induced by 5-CT; CYY054C suppressed the serotonin-induced blood pressure elevation in SB269970- treated rats and ameliorated the serotonin-induced hypotension in R96544-treated rats. In septic mice induced by intraperitoneal injection of LPS, posttreatment of CYY054C 300 μg/kg every 6 hour started from the 12 hour until the 48 hour after LPS injection improved the survival rate. Discussion: According to the results, the serotonin-induced coronary flow increases are mediated by the activation of 5-HT7 receptor in rat hearts. Metabolites of cytochrome P450s, small-conductance Ca2+-activated K+ channel, and intermediate- conductance Ca2+-activated K+ channel are involved in the serotonin-induced coronary flow increases in L-NAME-treated hearts, which resemble the mechanisms of EDHF-induced vasorelaxation. The role of large-conductance Ca2+-activated K+ channel in serotonin-induced coronary flow increases in L-NAME-treated hearts needs further investigation. All 8-pheylisoquinoline derivatives possess 5-HT2A receptor antagonist properties; among them, CYY054C is the most potent 5-HT2A receptor antagonist. CYY054C has a 5-HT7 receptor antagonizing effect, and the antagonizing effects against 5-HT2A and 5-HT7 receptors works in vivo. Posttreatment of CYY054C 300 μg/kg increases the survival rate of septic mice, but so far the relationship between the protective effect and its serotonin receptor antagonist properties are not clear. Conclusion: The serotonin-induced coronary flow increases comes from the activation of 5-HT7 receptor, and there is an EDHF-like component in the coronary flow increases in addition to NO. CYY054C is a potent antagonist to 5-HT2A and 5-HT7 receptors; it can provide benefit to septic mice, but the mechanism needs further investigations. | en |
dc.description.provenance | Made available in DSpace on 2021-05-14T17:47:27Z (GMT). No. of bitstreams: 1 ntu-104-D95443008-1.pdf: 5256484 bytes, checksum: 3c138a80373b1dc6b3e2df1998c91040 (MD5) Previous issue date: 2015 | en |
dc.description.tableofcontents | The Defense Committee Approval..........I
Preface..........II 中文摘要及關鍵字..........III Abstract and Keywords..........VI List of Abbreviations..........XII List of Pharmacological tools..........XIII 1. Introduction 1.1 General ideas of serotonin..........1 1.2 Serotonin receptors..........3 1.3 Cardiovascular effects of serotonin systems..........3 1.4 Current development of serotonin receptor modulators for treatments of cardiovascular diseases..........6 1.5 Role of serotonin in immune system and effects of serotonin receptor modulators in immune-related diseases..........7 1.6 Effects of serotonin receptor modulators in animal models of immune-related diseases..........8 1.7 Effects of serotonin receptor modulators on septic animal models..........8 1.8 The 8-phenylisoquinoline derivatives..........9 1.9 Aims of the present study..........9 2. Methods and Materials 2.1 Animals..........11 2.2 Chemicals and solutions..........11 2.3 Langendorff experiment..........11 2.3.1 Langendorff apparatus..........11 2.3.2 Preparation of isolated perfused rat heart..........12 2.3.3 Evaluation of influence of L-NAME on serotonin-induced coronary responses..........12 2.3.4 Repeatability of serotonin-induced responses in the absence or presence of low doses of L-NAME..........12 2.3.5 Effects of SB269970 and TCW295 on serotonin-induced coronary flow responses in L-NAME 10 μM-treated hearts..........13 2.3.6 Effects of the serotonin receptor antagonists on serotonin-induced coronary flow responses in isolated perfused hearts..........13 2.3.7 Effect of SB269970 on 5-CT-induced coronary flow responses in isolated perfused hearts..........13 2.3.8 Effects of the inhibitors of arachidonic acid metabolism on serotonin- induced coronary flow increases in L-NAME-treated rat hearts..........14 2.3.9 Effects of the Ca2+-activated K+ channel blockers on serotonin-induced coronary flow responses in L-NAME-treated hearts..........14 2.3.10 Preliminary tests on effects of large-conductance Ca2+-activated K+-channel openers on coronary flow..........15 2.4 Pharmacological properties of the 8-phenylisoquinoline derivatives 2.4.1 Effects of the 8-phenylisoquinoline derivatives on serotonin-induced vasoconstriction..........15 2.4.2 Effects of the 8-phenylisoquinoline derivatives on collagen-induced platelet aggregation..........16 2.4.3 Effects of CYY054C on serotonin injection-induced blood pressure alteration..........17 2.4.4 Effect of CYY054C on survival rates of LPS-induced endotoxemic mice..........18 2.5 Statistic analysis..........18 3. Results 3.1 Effects of nitric oxide synthase inhibitor L-NAME on serotonin-induced coronary flow responses 3.1.1 Effects of L-NAME 300 μM on serotonin-induced coronary flow responses..........19 3.1.2 Repeatability of serotonin-induced coronary flow response in the absence or the presence of L-NAME..........19 3.2 Effects of 5-HT7 receptor antagonists on serotonin-induced coronary flow responses in hearts treated with L-NAME 10 μM. 3.2.1 Effects of SB269970 on serotonin-induced coronary flow responses in L-NAME-treated hearts..........19 3.2.2 Effects of TCW295 on serotonin induced coronary flow responses in L-NAME-treated hearts..........20 3.2.3 Effect of 5-HT1B receptor antagonist on serotonin-induced coronary flow responses in the presence of L-NAME 10 μM..........20 3.3 Effects of serotonin receptor antagonists on serotonin receptor agonists- induced coronary flow responses in the absence of L-NAME..........20 3.4 Role of EDHF in serotonin-elicited coronary flow responses in L-NAME-treated hearts 3.4.1 Effects of the inhibitors of arachidonic acid metabolism on serotonin- induced coronary flow increases in L-NAME-treated hearts..........21 3.4.2 Effects of the blockers of small- and intermediate- conductance Ca2+-activated K+ channel on serotonin-induced coronary flow increases in L-NAME-treated hearts..........22 3.4.3 Effects of large-conductance Ca2+-activated K+ channel blockers on serotonin-induced coronary flow increases in L-NAME-treated hearts..........22 3.5 Effects of large-conductance Ca2+-activated K+ channel openers on coronary flow in L-NAME-treated hearts. 3.5.1 Effect of BMS191011 on coronary flow in L-NAME-treated hearts..........23 3.5.2 Effect of large-conductance Ca2+-activated K+ channel blockers on NS1619-induced coronary flow increases in L-NAME-treated hearts..........23 3.5.3 Effect of TEA on small- and intermediate- conductance Ca2+-activated K+-channels activator SKA-31-induced coronary flow increases..........24 3.6 Pharmacological properties of the 8-phenylisoquinoline derivatives 3.6.1 Effects of the 8-phenylisoquinoline derivatives on serotonin-induced vasoconstriction on isolated rat de-endothelium thoracic aorta..........24 3.6.2 Effects of the 8-phenylisoquinoline derivatives on serotonin-induced amplification of collagen-induced platelet aggregations in rat platelet-rich plasma..........24 3.6.3 Effect of CYY054C on coronary flow in isolated rat hearts..........24 3.6.4 Effect of CYY054C and serotonin receptor antagonists on serotonin-induced blood pressure alteration..........24 3.6.5 Effect of CYY054C on survival rates of LPS-induced endotoxemic mice..........25 4. Discussion 4.1 Subtype of serotonin receptor mediating serotonin-induced coronary flow increases in rat hearts..........26 4.2 Mechanisms of serotonin-induced coronary flow increases in isolated rat hearts..........29 4.3 Pharmacological properties of the 8-phenylisoquinoline derivatives..........33 4.4 Effects of CYY054C on endotoxemic mice..........35 4.5 Development therapeutic agents targeting peripheral 5-HT2A and 5-HT7 receptors..........39 4.6 Conclusion..........40 5. References..........41 6. Figures and captions..........62 | |
dc.language.iso | en | |
dc.title | 血清素引發大鼠心臟冠狀動脈反應之機轉以及八苯基異喹林化合物之藥理特性 | zh_TW |
dc.title | Mechanisms of serotonin-induced coronary responses in rat hearts and the pharmacological properties of the 8-phenylisoquinoline derivatives | en |
dc.type | Thesis | |
dc.date.schoolyear | 104-1 | |
dc.description.degree | 博士 | |
dc.contributor.oralexamcommittee | 顏茂雄,忻凌偉,陳文彬,楊鎧鍵 | |
dc.subject.keyword | 血清素,血清素受器,冠狀動脈,一氧化氮,內皮源過極化因子,八苯基異?林, | zh_TW |
dc.subject.keyword | serotonin,5-HT7,NO,EDHF,coronary,8-phenylisoquinoline,CYY054C, | en |
dc.relation.page | 86 | |
dc.rights.note | 同意授權(全球公開) | |
dc.date.accepted | 2015-09-30 | |
dc.contributor.author-college | 醫學院 | zh_TW |
dc.contributor.author-dept | 藥理學研究所 | zh_TW |
顯示於系所單位: | 藥理學科所 |
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