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腓深神经传入对刺激兔脑“防御反应区”诱发室性期前收缩的抑制作用

郭学勤, 李鹏

上海医科大学生理学教研室. 上海

摘要

实验在乌拉坦、氯醛糖麻醉兔上进行,用三碘季铵酚制动,由人工呼吸机维持通气。电刺激下丘脑穹窿周围区、中脑导水管周围灰质背侧部、延髓腹侧区均可引起血压升高肢体血流量增多,瞳孔扩大等防御反应的表现,并诱发室性期前收缩(刺激下丘脑、中脑导水管周围灰质与延髓腹侧“防御反应区”引起的室性期前收缩分别称为HVE、PVE、MVE)。用阈下电流同时刺激下丘脑与中脑“防御反应区”可发生明显升压反应和室性期前收缩。用电解法损毁双侧延髓腹侧区可使血压降低,刺激下丘脑或中脑引起的升压反应均减弱并消除HVE、PVE。

关键词： 防御反应; 室性期前收缩; 下丘脑; 中脑导水管周围灰质; 延髓腹侧区

Inhibitory effect of deep peroneal nerve input on the ventricular extrasystoles induced by stimulation of the defence area in the rabbit

Guo Xueqin, Li Peng

Department of Physiology, Shanghai Medical University. Shanghai, China

Abstract

Experiments were carried out on rabbits anesthetized with urethane and chloralose. The animals were immobilized with gallamine triethiodide and maintained by artificial ventilation. Stimulation of the perifornix area of hypothalamus, the dorsal part of midbrain periaqueductal gray and the ventral portion of medulla evoked a pressor response, an increase in the femoral blood flow, pupillary dilatation, and other components of the defence reaction as well as ventricular extrasystoles (ventricular extrasystoles induced by stimulation of the hypothalamus, midbrain periaqueductal gray and ventral portion of the medulla are abbreviated by HVE, PVE and MVE respectively). If the hypothalamic and midbrain defence areas were stimulated simultaneously with subthreshold current, a significant pressor effect and ventricular extrasystoles could be induced. After electrolytic lesion of bilateral ventral medullary areas, blood pressure dropped, the pressor response induced by defence areas stimulation was attenuated and the HVE and PVE were abolished. These results suggest that the ventral medullary area receives convergentinputs from the hypothalamic and midbrain defence areas and may be an essential link in the efferent pathway for HVE and PVE. Ventricular extrasystoles induced by stimulating unilateral hypothalamic, midbrain and ventral medullary defence areas or induced by stimulating bilateral hypothalamic and midbrain defence areas could be inhibited by deep peroneal nerve (DPN) stimulation. The inhibitory effect of DPN stimulation on extrasystoles induced by unilateral stimulation of the ventral medullary area could be abolished by destroying the contralateral ventral medullary area. The inhibitory effect of DPN stimulation on PVE or MVE persisted after an oblique transection of the brain stem from the anterior border of the superior colliculi to the preoptic chiasma, but could be abolished by a transection from the anterior border of the superior colliculi to the anterior border of the pons. The inhibitory effect of DPN stimulation on HVE, PVE or MVE still existed after electrolytic lesion of the pituitary. It is suggested that the inhibitory effect of DPN stimulation on HVE, PVE and MVE does not depend upon the integrity of pituitary, but does depend upon the brain structures rostral to the midbrain. The ventral portion of the medulla also plays a part in the inhibitory effect of DNP stimulation.

Key words: Defence reaction;Ventricular extrasystole;Ventral medullary area;Hypothalamus;Midbrain periaqueduct gray

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引用本文：

郭学勤, 李鹏. 腓深神经传入对刺激兔脑“防御反应区”诱发室性期前收缩的抑制作用[J]. 生理学报 1986; 38 (3): .

Guo Xueqin, Li Peng. Inhibitory effect of deep peroneal nerve input on the ventricular extrasystoles induced by stimulation of the defence area in the rabbit. Acta Physiol Sin 1986; 38 (3): (in Chinese with English abstract).