- 學位論文
電針在ST36穴位在慢性類固醇誘發胰島素減敏大鼠降血糖效果及其降血糖有關的傳遞路徑相關研究
The study of hypoglycemic effect of electroacupuncture by reducing insulin resistance in chronic steroid induced insulin resistance rats and signaling pathways associated with hypoglycemic activity of ST 36 electroacupuncture
摘要
此研究主要是要建立一個慢性長期使用類固醇的大鼠所造成胰島素阻抗steroid induced insulin resistant(SIIR)動物模型後,來探討電針在足三里穴位(S36)的降血糖效果。期望能夠找到對於因長期使用類固醇引起的胰島素阻抗現象的效果，另一種治療的方式。此研究的主要目的在於藉由監測血液中的游離酯肪酸以及胰島素訊息蛋白分子看確定電針是不是有對於因慢性類固醇誘發的大鼠產生藉血糖的效果，並且利用靜脈葡萄糖耐受性試驗及胰島素挑戰試驗來評估電針對慢性類固醇誘發的大鼠的效應，以及評估電針改善慢性類固醇誘發胰島素減敏大鼠的機轉及胰島素訊息蛋白的關係。這實驗模擬慢性使用類固醇使用如臨床上使用低劑量的情況給予dexamethason每日給予1毫克/公斤，持續給予五天，以此方式成功的誘發出慢性類固醇造成胰島素阻抗現象的大鼠模型。在以此因類固醇所成功誘發出的大鼠分成電針組以及非電針組兩組，然後測此兩組大鼠中的血糖值、胰島素激發試驗以及靜脈葡萄糖耐量試驗來比較此兩組動物模型的血糖差異。此外兩組動物模型的血中游離脂肪酸以及胰島素訊息傳遞路徑中的相關蛋白，如IRS1及GLUT 4也同時被檢測。其結果顯示電針在可以降低慢性類固醇造成胰島素阻抗現象的大鼠血中的游離脂肪酸以及增加胰島素敏感度的作用而達到降血糖的效果。未來需要進一步的臨床試驗來評估電針是不是可以成為運用來治療一些需長期使用類固醇導致的糖尿病病人的另類新治療方式。進一步的實驗目的，根據我們先前相關的動物實驗結果發現電針可達到降血糖的效果，此效果可能與細胞內的訊息傳遞路徑有關，為了了解其可能的訊息傳遞路徑，我們借用高通量基因序列分析(microarray)的研究方式來探討及試著找出電針在糖尿病大鼠的S36穴位其造成降血糖的可能調控的訊息傳遞路徑研究方法為使用鏈脲佐菌素(Streptozotocin)所誘發的糖尿病大鼠將其分成兩組,第一組為實驗組有八隻糖尿病大鼠；第二組為對照組同樣有八隻糖尿病大鼠。在實驗組給予電針於起始點、30分鐘及60分鐘抽測其血糖值，並且在電針後從兩組的大鼠大腿的腓腸肌取出標本進行高通量基因序列分析。結果顯示電針會明顯的造成兩組大鼠在30分鐘及60分鐘時血糖的下降，且在高通量基因序列分析上發現電針組與非電針組的基因序列表現差異比較，結果顯示在細胞黏附因子(cell adhesion molecules)與第一型糖尿病(type 1)的相關上調基因在電針組會與非電針組出現顯著的差異。結論是細胞黏附因子與電針在鏈脲佐菌素(Streptozotocin)所誘發的第一型糖尿病大鼠的訊息傳遞路徑有關。進一步的研究來確定電針引起的降血糖有關的訊息傳遞路徑是未來需要努力的題目。
並列摘要
This study is designed to evaluate the treatment effect of electroacupuncture (EA) in chronic steroid induced insulin resistant rat model. An alternative therapy is explored to reduce the chronic steroid induced insulin resistance.The aim of this study is to determine (1) if EA treatment can produce hypoglycemic effect and (2) inhibit the development of glucocorticoid-altered insulin sensitivity in chronic status and to (3) explore the mechanisms of EA by assaying plasma FFAs and proteins of insulin signal pathway. Intravenous glucose tolerance test (IVGTT) and insulin challenge test (ICT) were applied to evaluate the effect of EA on steroid induced insulin resistance (SIIR) rats. Finally, this study evaluates proteins of insulin signaling pathway to investigate the mechanisms by which EA improves the insulin resistance of SIIR rats. We hypothesized that electroacupuncture can produce a hypoglycemic effect in chronic steroid induced insulin resistance diabetes rat model. A diabetes rat model was created by using clinical-like dose dexamethasone, 1 mg/kg, i.p. once a day chronic to induce insulin resistance for 5 days. Then the steroid induced insulin resistant (SIIR) rats were randomly divided into SIIR+EA group and SIIR group. Plasma glucose, insulin challenge test (ICT) and intravenous glucose tolerance test (ivGTT) were used to test the change of plasma glucose levels between SIIR+EA group and SIIR group. The plasma free fatty acids (FFA) and related proteins of the insulin signaling pathway, such as IRS-1 and GLUT4 were also checked to explore the effect of EA on recovering insulin sensitivity of SIIR rats. The results showed that EA could decrease the FFA level and increase insulin sensitivity in SIIR rats. Further clinical studies are needed to determine whether EA can be an alternative and effective treatment for patients for whom chronic usage of dexamethasone is needed by reducing insulin resistance. Data on expression of all genes in a biological sample can be achieved in one experiment using the microarray method, the results of which can be analyzed to determine the potential pathways involved in a given process and identify potential therapeutic targets. Then the microarray analysis experiment was done to explore the possible signaling pathway related to hypoglycemic effect induced by the EA. Previous animal studies have reported a hypoglycemic effect of EA and suggested that the mechanisms are closely related to intracellular signaling pathways. The aim of this study was to screen potential for intracellular signaling pathways that are upregulated by EA at bilateral ST36 in rats with diabetes using microarray analysis. Streptozotocin (STZ) - induced diabetic rats were randomly assigned to experimental (EA, n=8) or control (non-EA, n=8) groups. Plasma glucose levels were measured at baseline, 30 and 60 minutes, and microarray analysis was performed on samples of the gastrocnemius muscle. Relative to baseline values, EA significantly reduced plasma levels of glucose at 30 and 60 minutes. The microarray pathway analysis showed that cell adhesion molecules and type 1 DM gene sets were both upregulated in EA versus non-EA groups (p<0.05). Cell adhesion molecules might be related to the hypoglycemic effect induced by EA in rats with STZ-induced type I diabetes. Future research will be required to examine the involvement of related intracellular signaling pathways.