Importance of Sympathetic Nervous System on Vagal Escape

交感神經系統對於迷走神經抑心作用暫時停頓的重要性

郭重雄(J. S. Kuo) ； 李泰明(T. M. Lee) ； 蔡作雍(C. Y. Chai)

《The Chinese Journal of Physiology》 20卷4期 (1970/12) Pp. 285-294

摘要

用氯醛醣麻醉的狗，以方形電波刺激迷走神經近心端兩分鐘，以研究迷走神經抑心作用暫時停頓現象，發現阻斷頸動脈竇神經傳導或注射腎上腺素，加速停頓現象的產生。切除兩側星狀神經節，延緩停頓現象的產生及降低停頓前半段的心跳率。切除兩側腎上腺則僅能降低後半段的停頓心跳率。合併切除星狀神經節與腎上腺則降低整個時程停頓的心跳率。在星狀神經節與腎上腺完整時，由靜脈注射Neostigmine，對停頓現象無甚影響，但在該兩組織切除後，卽顯明地延緩之。在刺激迷走神經心臟停頓期中，降低心室的擴張或兼行灌注充氧血液(Oxygenated blood)入冠狀動脈，則能減少停頓現象，但其作用必須在星狀神經節與腎上腺被切除後才顯著。由此實驗顯示：完整的心交感神經與腎上腺髓質為產生迷走神經抑心作用暫時停頓不可缺少的機構。

並列摘要

The cut vagus peripheral ends were stimulated for 2 minutes in dogs under chloralose. Bilateral blockade of carotid sinus nerves or epinephrine administration markedly augmented the vagal escape. Bilateral removal of stellate ganglia delayed the escape onset and slowed down the escape rhythm of the early and removal of adrenal glands the late half period of stimulation. Combined removal of the ganglia and glands intensified the delay and the slowing of the whole course of stimulation. Intravenous administration of neostigmine 0.02-0.05 mg/kg affected very little the pattern of escape, with intact ganglia and glands, but with removal, greatly suppressed the escape. During the period of cardiac arrest on stimulation, release of ventricular distention and/or perfusing the coronary arteries with oxygenated blood delayed the onset and slowed down the rhythm. Again the effects were apparent only with combined removal of the ganglia and adrenal glands. The data thus summarize that an intact cardiac adrenosympathetic function is in the vagal escape mechanism, while the result of ventricular distension release might imply the adrenosympathetic mediation of normal vagal escape with no visible manifestation.