Effects of Increased Intracranial Pressure on the Central Cardiovascular Control Mechanism

顱內壓增加對中樞心臟血管管制機構之影響

郭重雄(J. S. Kuo) ； 陳幸一(H. I. Chen) ； 王師揆(S. K. Wang) ； 蔡作雍(C. Y. Chai)

《The Chinese Journal of Physiology》 21卷2期 (1972/12) Pp. 89-99

摘要

利用麻醉之貓實驗增加顱內壓對血壓及心跳的影響。顱內壓增加時，依增加程度及動物反應之不同，血壓可能升高或降低，心跳亦可變慢及加快。一般之反應為：顱內壓增加低於50毫米水銀柱時，血壓及心跳均無顯着變化；50至70毫米則常見心跳變慢；80毫米以上則產生血壓升高及心跳加快。在血壓升高及心跳變慢同時發生之情況下，phentolamine使血壓升高反應消失，但對心跳變慢之反應作用極微。輕度或中度增加顱內壓，而在血壓心跳不顯變化之情況下，對於注射Epinephrine或刺激迷走神經中樞端所引起之反射性心跳變慢有加强作用。在切除迷走神經動物，增加顱內壓對於夾閉頸動脈，刺激延腦升壓區或刺激坐骨神經中樞端三者所引起之升壓反射並無加强作用。本實驗顯示中樞心臟血管之管制機構中，副交感部份比交感部份對顱內壓增加較為敏感。而且由顱內壓增加引起之心跳變慢，並非因高血壓引起感壓反射之結果，而是直接激發中樞迷走神經機構的一種反應。

並列摘要

J. S. Kuo, H. I. Chen, S. K. Wang, and C. Y. Chai. Effects of increased intracranial pressure on the central cardiovascular control mechanism. Chinese J. Physiol, 21(2): 89-99, 1972-The effects of increased intracranial pressure (IIP) on arterial blood pressure and heart rate were studied in anesthetized cats. IIP, depending on the degree of pressure increase, produced various combinations of cardiovascular responses, i. e., depressor and pressor; cardiodecelerator and cardioaccelerator. In general, IIP below 50mm Hg did not produce noticeable cardiovascular changes. IIP of 50-70 mm Hg most commonly produced bradycardia, of 80mm Hgor above it produced pressor response and tachycardia. When both hypertension and bradycardia occurred concomitantly, elimination of the pressor response by phentolamine affected the bradycardia only slightly. Slight to moderate IIP, which did not alter the resting cardiovascular parameters, potentiated the reflex bradycardia induced by intravenous epinephrine or stimulation of the afferent vagus. In vagotomized animals, IIP did not potentiate the pressor responses upon carotid occlusion, or those obtained from stimulation of the pressor area of the medulla and the afferent sciatic nerve. These observations suggest that the parasympathetic component of the central cardiovascular control mechanism is more sensitive to IIP than the sympathetic component; and that direct rather than reflex activation of the parasympathetic component principally contributes to the IIP-induced bradycardia.

並列關鍵字

Intracranial pressure Hypertension ； Bradycardia Sympathetic nerve Parasympathetic nerve