查詢結果分析
來源資料
相關文獻
- 冠狀循環適應運動訓練的調節機制
- Nitro変-L-Arginine Methyl Ester Decreases Minimum Alveolar Concentration of Isoflurane and Reduces Brain Nitric Oxide Synthase Activity in Rats
- 長期阻斷內生性一氧化氮對血壓的影響:正常鼠與高血壓鼠間的比較
- 使用吸入性一氧化氮(NO)治療成人呼吸窘迫症(ARDS):利?或弊?
- Altering Sphingomyelin Signaling in Vessels from Stroke-prone Spontaneously Hypertensive Rats
- 運動對一氧化氮合成酶基因表現的影響
- 一氧化氮與上呼吸道
- 敗血性休克的致病機轉和治療之探討:生理、生化、藥物和藥理的角度
- 聚醣類誘導魚隻產生一氧化氮
- 以吸入一氧化氮(Nitric Oxide)治療新生兒肺疾患
頁籤選單縮合
題 名 | 冠狀循環適應運動訓練的調節機制=Mechanism of Exercise-Induced Adaptation in Coronary Circulation |
---|---|
作 者 | 林嘉志; 謝伸裕; | 書刊名 | 體育研究 |
卷 期 | 4 1997.12[民86.12] |
頁 次 | 頁69-82 |
分類號 | 528.9013 |
關鍵詞 | 冠狀循環; 運動訓練適應; 調節機制; 內皮細胞層; 一氧化氮; Coronary circulation; Exercise; Adaptation; Nitric oxide synthase; Endothelium; |
語 文 | 中文(Chinese) |
中文摘要 | 在運動狀態之下,心臟作功的頻率必須增加,以提供全身活動的肌肉、腺體的氧 氣及能量來源,而心肌細胞本身則仰賴冠狀循環( coronary circulation )供應其唯一能 量產生的形式 - 氧化磷酸化反應( oxidative phosphorylation )的原料。冠狀循環之於 運動訓練的適應機制表現於兩方面:第一, 血流速率的增加,主要歸因於:( 1 )動脈的 血管擴張作用( vasodilation )(阻力減少約 30-50% ); ( 2 )動脈血壓的增加(根 據 F= △ P/R,血流 = 血壓變化量 / 血管阻力);第二,微血管網物質交換率的增加,其 直接的影響是造成心肌細胞對氧攝取率的增加, 而物質交換率又為交換面積( exchange area )與通透性( permeability )所影響。 就適應增加的程度而言,動物實驗顯示微血 管網物質交換率約增加 50%,血流速率則增加約 22%。若再細究這兩種適應機制的調節機制 ,依目前現有的實驗證據只能對微血管網物質交換率增加的機制作推測性的猜測,但是對血 流速率增加的調節機制則有較完整的探討。 血管的阻力因素被認為是血流速率的主要控制因素。血管的阻力大小與血管的管徑的四次方 成反比關係( R=8 η L/ π r �捸^,而管徑的大小又由血管周圍平滑肌的收縮活性所調控 。一般而言,調控血管平滑肌收縮活性的機制可分成中央與局部兩大類,但就冠狀循環而言 ,局部調控機制較為重要。 局部調控機制又分成三種不同的調控方式:( 1 )代謝性調控 ( metabolic control ),( 2 )肌源性調控( myogenic control ), ( 3 )內皮細 胞層媒介性調控( endothelium-mediated control )。其中以內皮細胞層媒介性調控(合 成一氧化氮)主宰著中大型管徑冠狀動脈的舒張程度,因此所謂的適應便是指內皮細胞層的 一氧化氮合成�t對於運動訓練刺激形成的活性增加,甚至基因表現。在我們初步的實驗結果 顯示:經過運動訓練的大白鼠,其胸主動脈的常駐型內皮細胞一氧化氮合成�t( ec-NOS ) 的 mRNA 明顯高於對照組,顯示基因表現的確增加。有關運動適應機制的問題隨著分子生物 學的進展而愈來愈明朗,許多更深入的問題也有待進一步利用新的技術加以解決。 |
英文摘要 | To provide sufficient amounts of oxygen and energry to activated skeletal muscles and glands, heart works more efficiently during exercise. Myocytes themselves are fed on nutrients, especially adequate oxygen, which exists in blood vessels of coronary circulation, to produce energy almost through oxidative phosphorylation. Mechanism of exercise-induced adaptation in coronary circulation attributes to increase of blood flow (22%) and increase exchange rate of capillaries (50%). Due to limited evidences, little is known about the regulatory mechanism of increase exchange rate in capillaries. However, accumulated results shows that arterial resistance is the primary factor which effects increase of blood flow. Vessel resistance is inversely proportional to the fourth power of vessel radius (R=8ηL/πr4) and vessel radius is regulated by the activity of smooth muscle cells. Local contro mechanism predominates in regulating coronary circulation though central control mechanism exists. Three types of local control mechanisms are included: metabolic control, myogenic control and endothelium-mediated control. Exercise-induced adaptation in coronary blood vessels may attribute to the increase activity of nitric oxide synthase located within endothelium, even increase in gene expression. Preliminary results on aorta in our lab showed that mRNA level of nitric oxide synthase (ec-NOS) is obviously higher in exercise-training rat than sedentary group. Shear stress responses are also discussed in the article. Further research is needed to highlight the effects of exercise training on vascular system with different radii. |
本系統中英文摘要資訊取自各篇刊載內容。