本文關(guān)鍵詞：雄激素拮抗糖皮質(zhì)激素引起的大鼠骨骼肌萎縮的作用與機制研究　出處：《中國人民解放軍軍醫(yī)進修學(xué)院》2007年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 雄激素類 糖皮質(zhì)激素類 胰島素樣生長因子-1 泛素蛋白連接酶 肌肉萎縮

【摘要】： 目的：糖皮質(zhì)激素是引起骨骼肌萎縮的重要介質(zhì)。多種原因如嚴(yán)重?zé)齻�、膿毒癥等均可引起糖皮質(zhì)激素大量釋放，導(dǎo)致骨骼肌萎縮。業(yè)已明確，骨骼肌萎縮對機體危害極大，如導(dǎo)致機體免疫力下降、感染率增加、患者活動延遲等，這都嚴(yán)重影響了患者的生存質(zhì)量和疾病預(yù)后。因此，預(yù)防和治療糖皮質(zhì)激素引起的骨骼肌萎縮具有重要的臨床意義。研究發(fā)現(xiàn)，雄激素作為一種促合成代謝激素可能具有拮抗糖皮質(zhì)激素引起的骨骼肌萎縮的作用，但其作用仍不明確，機制也尚未闡明。該研究通過動物實驗旨在闡明雄激素對糖皮質(zhì)激素引起的大鼠骨骼肌萎縮(特別是骨骼肌蛋白高分解代謝)的拮抗作用，并探討與骨骼肌蛋白代謝密切相關(guān)的IGF-1信號傳導(dǎo)通路在雄激素拮抗糖皮質(zhì)激素引起的骨骼肌萎縮中的作用。 方法：雌性SD大鼠160只，隨機分為四組：(1)對照組注射生理鹽水與香油(分別為地塞米松與睪酮的溶劑)；(2)地塞米松組注射地塞米松與香油；(3)睪酮組注射生理鹽水與睪酮；(4)睪酮+地塞米松組注射地塞米松與睪酮。分別在開始注射地塞米松或生理鹽水后1天、3天、5天、10天麻醉后處死動物，每個時間點10只動物，留取肌肉(腓腸肌、趾長伸肌、比目魚肌、脛骨前肌、跖肌)、血漿與尿標(biāo)本。實驗過程中每日稱量體重，，實驗結(jié)束時稱量肌肉重量。肌纖維橫斷面在HE染色或免疫組化染色之后采用圖像采集與分析系統(tǒng)計算橫斷面面積；骨骼肌中與尿中3-甲基組氨酸(3-MH)采用高效液相色譜分析技術(shù)進行檢測；血漿睪酮水平采用放射免疫學(xué)方法進行檢測；血漿IGF-1蛋白水平采用酶聯(lián)免疫吸附試驗(ELISA)進行檢測；骨骼肌中蛋白激酶B(Akt)、糖原合成酶激酶-3β(GSK-3β)、70kDa核糖體蛋白S6激酶(p70S6K)的活性采用Western blot方法進行檢測；骨骼肌中胰島素樣生長因子-1(IGF-1)與二種泛素蛋白連接酶muscle atrophy F-box(MAFbx)、muscle RING finger-1(MuRF1)mRNA的表達采用定量PCR方法進行檢測。 結(jié)果：1．地塞米松使大鼠體重和多種肌肉重量進行性降低，并使多種肌肉的肌纖維橫斷面面積減小。睪酮可以部分拮抗地塞米松引起的大鼠體重、肌肉重量的降低和肌纖維橫斷面面積的減小。2．睪酮可以部分拮抗地塞米松引起的大鼠腓腸肌中3-MH含量和尿中3-MH釋放量的增加。3．睪酮可以拮抗地塞米松引起的大鼠腓腸肌中IGF-1 mRNA表達的下降，但不能拮抗地塞米松引起的大鼠血漿中IGF-1蛋白水平的下降。4．地塞米松可以明顯降低大鼠腓腸肌中Akt、p70S6K的活性；睪酮可以增加腓腸肌中Akt、p70S6K的活性，降低GSK-3p的活性，并可以部分拮抗地塞米松對Akt、p70S6K活性的影響。5．地塞米松可使大鼠腓腸肌中泛素蛋白連接酶MuRF1與MAFbx mRNA表達明顯上調(diào)，而睪酮并不能拮抗地塞米松對這二種基因表達的影響。 結(jié)論：1．雄激素可以減輕糖皮質(zhì)激素引起的骨骼肌萎縮。2．雄激素可以部分拮抗糖皮質(zhì)激素引起的骨骼肌蛋白高分解代謝。3．雄激素拮抗糖皮質(zhì)激素致骨骼肌萎縮的作用至少部分是通過雄激素對IGF-1信號通路中與骨骼肌蛋白合成代謝有關(guān)的信號分子(Akt、GSK-3β、p70S6K)的調(diào)控實現(xiàn)的。4．雄激素拮抗糖皮質(zhì)激素引起的骨骼肌蛋白高分解代謝的作用可能并不是通過對IGF-1下游與骨骼肌蛋白分解代謝有關(guān)的泛素蛋白連接酶MuRF1與MAFbx的調(diào)控實現(xiàn)的。
[Abstract]:Objective: glucocorticoids are important mediators to cause muscle atrophy. A variety of reasons such as severe burns, sepsis and other induce glucocorticoid release, leading to skeletal muscle atrophy. Clear, skeletal muscle atrophy and does great harm to the body, such as lead to decreased immunity, infection rate increased in patients with active delay, this have a serious impact on the quality of life of patients and the prognosis of the disease. Therefore, prevention and treatment of glucocorticoid induced skeletal muscle atrophy has important clinical significance. The study found that androgen as an anabolic hormone can antagonize glucocorticoid induced atrophy of skeletal muscle function, but its function is still not clear. The mechanism also has not yet been elucidated. The study by animal experiments aimed at elucidating androgen on glucocorticoid induced rat skeletal muscle atrophy (especially skeletal muscle protein catabolism) antagonist The effect of IGF-1 signaling pathway, which is closely related to skeletal muscle protein metabolism, is explored in the action of androgen antagonism on skeletal muscle atrophy induced by glucocorticoid.
Methods: 160 female SD rats were randomly divided into four groups: (1) control group were injected with saline and sesame oil (respectively, dexamethasone and testosterone solvent); (2) dexamethasone injection of dexamethasone and sesame oil; (3) testosterone group were injected with saline and testosterone; (4) testosterone + dexamethasone injection dexamethasone and testosterone. Respectively before injection of dexamethasone or saline after 1 days, 3 days, 5 days, 10 days after anesthesia were sacrificed animal, 10 rats at each time point for animal muscle (gastrocnemius muscle, extensor digitorum longus and soleus, tibialis anterior muscle, plantaris muscle), plasma and urine samples experiments. In the process of daily weighing, weighing at the end of the experiment. The muscle fiber cross-sectional muscle weight after HE staining and immunohistochemical staining using image acquisition and analysis system to calculate the cross-sectional area; in skeletal muscle and urine 3- methylhistidine (3-MH) analysis by HPLC To detect; plasma testosterone levels were detected by radioimmunoassay method; plasma levels of IGF-1 protein by enzyme-linked immunosorbent assay (ELISA) were detected; protein kinase B in skeletal muscle (Akt), glycogen synthase kinase -3 beta (GSK-3 beta), 70kDa ribosomal protein S6 kinase (p70S6K) activity by Western blot method detection; insulin-like growth factor -1 in skeletal muscle (IGF-1) and two muscle atrophy F-box ubiquitin protein ligase (MAFbx), muscle RING finger-1 (MuRF1) mRNA expression was detected by quantitative PCR method.
Results: 1. dexamethasone make weight and muscle weights of rats were decreased, and the muscle fiber CSA decreased. Testosterone can cause weight part of dexamethasone treated rats, reduce muscle weight and muscle fiber cross-sectional area decreased.2. testosterone may cause a part of dexamethasone in gastrocnemius muscles of rats 3-MH content the release amount of 3-MH in urine and.3. increased testosterone can express IGF-1 mRNA antagonist induced by dexamethasone in gastrocnemius muscles of rats decreased, but the level of IGF-1 protein caused not dexamethasone in rat plasma by.4. dexamethasone can significantly reduce rat gastrocnemius in Akt, the activity of p70S6K; testosterone can increase the gastrocnemius in Akt and the activity of p70S6K, decreased the activity of GSK-3p, and can antagonize the effects of dexamethasone on Akt, dexamethasone p70S6K activity can influence.5. The expression of ubiquitin protein ligase MuRF1 and MAFbx mRNA in the gastrocnemius muscle of rats was obviously up-regulated, but testosterone did not antagonize the effect of dexamethasone on the expression of these two genes.
Conclusion: 1. can reduce androgen induced by glucocorticoid in skeletal muscle atrophy.2. androgen can partially prevent glucocorticoid induced skeletal muscle protein catabolism of androgen antagonist.3. glucocorticoid induced by skeletal muscle atrophy, at least in part by signaling molecules associated with androgen on skeletal muscle protein synthesis and metabolism in the IGF-1 signaling pathway (Akt GSK-3, beta, p70S6K).4. androgen antagonist of glucocorticoid induced regulation of skeletal muscle protein catabolism may not be achieved through the regulation of IGF-1 downstream and skeletal muscle protein catabolism of the ubiquitin protein ligase MuRF1 and MAFbx.

【學(xué)位授予單位】：中國人民解放軍軍醫(yī)進修學(xué)院
【學(xué)位級別】：博士
【學(xué)位授予年份】：2007
【分類號】：R363

【引證文獻】

相關(guān)期刊論文 前1條

1 馬延超;朱榮;李俊平;;腺苷酸活化蛋白激酶與骨骼肌蛋白質(zhì)降解[J];中國組織工程研究;2012年02期

相關(guān)博士學(xué)位論文 前1條

1 張海軍;非編碼RNA在大鼠嚴(yán)重燙傷后早期脛骨前肌消耗中的表達譜變化及其生物信息學(xué)分析[D];中國人民解放軍醫(yī)學(xué)院;2014年

相關(guān)碩士學(xué)位論文 前1條

1 施桃;雄激素對運動大鼠骨骼肌Akt/GSK3β表達的影響[D];北京體育大學(xué);2012年

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