本文關(guān)鍵詞：維生素E對鏈脲菌素所致胰島β細胞損傷的干預研究　出處：《重慶醫(yī)科大學》2007年碩士論文　論文類型：學位論文

  更多相關(guān)文章： 維生素E 胰島β細胞 氧化損傷 凋亡

【摘要】： 目的:探討維生素E(vitamin E)對鏈脲菌素(streptozotocin,STZ)所致大鼠離體胰島β細胞損傷的保護途徑及可能的機制。 方法:1.分組:分離1-3日齡Wistar大鼠胰腺進行體外培養(yǎng),培養(yǎng)細胞分為4組:①正常對照組:培養(yǎng)的胰島細胞不作任何干預處理;②維生素E組:培養(yǎng)液中僅加入終濃度為0.1mM的維生素E作用60分鐘;③STZ組:培養(yǎng)液中僅加入終濃度為2.2mM的STZ作用30分鐘;④保護組:I-IV組。培養(yǎng)液中分別加入0.0125mM、0.025mM、0.05mM、0.1mM的維生素E預作用60分鐘后,再加入終濃度為2.2 mM的STZ作用30分鐘。各組作用時間一到,離心棄上清液,再用新鮮培養(yǎng)液重懸細胞,繼續(xù)培養(yǎng)18小時后進行各項指標檢測。2.檢測:放射免疫法檢測培養(yǎng)上清液中胰島素含量,分光光度計分別測量培養(yǎng)上清液中超氧化物歧化酶(SOD)活性和丙二醛(MDA)水平,透射電鏡觀察細胞形態(tài),Hoechest33258熒光染色觀察熒光強度,流式細胞儀定量檢測細胞凋亡率,分光光度法測量胰島細胞特異性半胱氨酸酶-3(caspase-3)活性。 結(jié)果:與正常對照組比較,維生素E組胰島素含量、SOD活性、MDA水平、細胞凋亡率及caspase-3活性未見明顯變化(p㧐0.05)。單純STZ作用后,胰島素含量、SOD活性顯著降低,MDA水平、細胞凋亡率及caspase-3活性明顯升高,與正常對照組比較,p㩳0.05。同時,電鏡觀察到凋亡細胞,Hoechest33258熒光染色發(fā)現(xiàn)發(fā)明亮淡藍色強熒光細胞數(shù)顯著增多。而在STZ作用前給予不同濃度維生素E作預處理的四個保護組,胰島素含量、SOD活性、MDA水平雖未恢復到正常對照組水平,但其下降或上升的程度較STZ組出現(xiàn)明顯抑制(p㩳0.05)。而且其抑制程度隨維生素E濃度的增大而增強(各保護組間比較p㩳0.05),其中以終濃度為0.1mM的保護作用最強,呈現(xiàn)出一定的劑量依賴性趨勢。在終濃度為0.1mM的維生素E保護組,細胞凋亡率、caspase-3活性分別為7.84±1.75%和0.153±0.034,與STZ組比較,差異有顯著性(p㩳0.05)。 結(jié)論:維生素E對于STZ誘導的胰島β細胞損傷有保護作用,并呈現(xiàn)出一定的劑量依賴性趨勢。其機制可能與增加SOD活性,清除氧自由基,減少脂質(zhì)過氧化,降低MDA水平,從而降低caspase-3活性,減少胰島細胞凋亡有關(guān),抗氧化性可能是其眾多保護胰島β細胞功能的機制之一。
[Abstract]:Objective: To investigate the protective pathway and possible mechanism of vitamin E (vitamin E) on pancreatic islet beta cell injury induced by streptozotocin (STZ) in rats.
Methods: 1. groups: isolated pancreas of 1-3 day old Wistar rats were cultured in vitro. The cultured cells were divided into 4 groups: normal control group: islet cells cultured without any intervention treatment; the vitamin E group: Cultured only with the final concentration of liquid of vitamin E 0.1mM for 60 minutes; group STZ: the medium only with the final concentration of STZ 2.2mM for 30 minutes; the protection group: I-IV group were cultured with 0.0125mM, 0.025mM, 0.05mM, 0.1mM and vitamin E pretreatment for 60 minutes, then add a final concentration of 30 STZ for 2.2 minutes. Each mM action time to centrifugal discard the supernatant with fresh medium cell suspension cultured for 18 hours after the index to detect the.2. content in the supernatant of culture: insulin was measured by radioimmunoassay and spectrophotometry were measured in supernatants of superoxide dismutase (SOD) activity and malondialdehyde (MDA) The cell morphology was observed by transmission electron microscope. The fluorescence intensity was observed by Hoechest33258 fluorescence staining. The apoptosis rate was quantitatively detected by flow cytometry, and the activity of -3 (caspase-3) was measured by spectrophotometry.
Results: compared with normal control group, vitamin E group insulin content, SOD activity, MDA level, significant changes in cell apoptosis rate and the activity of Caspase-3 was not (P? 0.05). The insulin content in STZ group, and SOD activity decreased significantly, the level of MDA, the apoptosis rate and caspase-3 activity increased significantly, and the normal control group comparison of P? 0.05. were observed at the same time, apoptotic cells, Hoechest33258 staining found a bright blue fluorescence cells increased significantly. While in STZ before treated with different concentrations of vitamin E four pretreatment protecting group, insulin content, SOD activity, MDA levels did not return to the normal level of the control group however, the decrease or increase than the degree of group STZ significantly inhibited (P? 0.05). But the degree of inhibition increased with the increasing concentration of vitamin E (the protection group P? 0.05), the final concentration of 0.1mM's protective effect Strong, showing a certain dose dependent trend. In the vitamin E protection group with final concentration of 0.1mM, the apoptotic rate and caspase-3 activity were 7.84 + 1.75% and 0.153 + 0.034, respectively, compared with STZ group, the difference was significant (P? 0.05).
Conclusion: vitamin E on islet beta cell injury induced by STZ has a protective effect, and showed a dose-dependent trend. Its mechanism may be related to increased SOD activity, scavenging oxygen free radicals, reducing lipid peroxidation, reduce the level of MDA, thereby reducing the activity of Caspase-3, reduce the apoptosis of islet cells, antioxidant activity may be one of the the protection mechanism of beta cell function.

【學位授予單位】：重慶醫(yī)科大學
【學位級別】：碩士
【學位授予年份】：2007
【分類號】：R341;R96

【參考文獻】

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1 楊中民,高秋華,郭軍,田衛(wèi)群,徐輝碧;膽紅素與維生素E對糖尿病大鼠肝及胰組織中NO和NOS的影響[J];廣東醫(yī)學;2003年03期

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本文編號：1417738