Cardiac Responses upon Intense Cerebral Compression in Rats

強烈壓迫鼠大腦時心臟之反應

蔡作雍(C. Y. Chai) ； 陳幸一(H. I. Chen)

《Journal of Medical Sciences》 1卷1期 (1975/01) Pp. 1-10

摘要

以機械方法強烈壓迫麻醉鼠之大腦，除引起劇烈之加壓反應外，初期可見短暫而明顯之心跳變慢，繼之以晚期之心跳加快，以及末期之心跳變慢且至完全停止。在心跳加快時， 心電圖之ST，J及T波均有改變。心室性額外收縮在心跳加快期間經常出現，而在心跳變慢時，僅偶而可見。本實驗曾研究急性切除腎上腺、去大腦、切斷迷走神經，以及脊髓橫斷對前述心臟各種反應之影響。吾人發現（一）此類心臟反應不受高級中樞之管制，且與腎上腺分泌之兒茶酚胺無關。（二）初期心跳變慢係直接興奮迷走神經所致，而非感壓反射之作用。（三）晚期心跳加快，ST，J及T波之改變，以及心室額外收縮，主要係興奮交感神經所致，迷走神經對此反應並不重要。

並列摘要

In anesthetized rats, in addition to marked pressor response, intense cerebral compression (ICC) by mechanical means produced a transient but marked bradycardia, a late tachycardia and a terminal bradycardia to cardiac arrest. Changes of ST or J junction and T wave in ECG were observed during the tachycardia. Ventricular extrasystoles were consistently observed during the tachycardiac but only occasionally during the bradycardiac phase. The effects of acute adrenalectomy, decerebration, vagotomy and spinal transection on the cardiac responses have been evaluated. It was found that: 1) These cadiac changes were independent of the higher centers or catecholamines release from the adrendals. 2) The initial bradycardia was mediated through direct vagal activation rather than baroceptor reflex action. 3) The late tachycardia with changes of ST, J and T wave and ventricular extrasystoles was principally produced through sympathetic activation. The vagal mechanism was not important.