CARDIOVASCULAR EFFECTS OF ATRIAL EXTRACTS IN ANESTHETIZED RATS
CARDIOVASCULAR EFFECTS OF ATRIAL EXTRACTS IN ANESTHETIZED RATS
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DOI：
10.1139/y84-135
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发表时间：
1984-01-01
影响因子：
2.1
通讯作者：
SONNENBERG, H
中科院分区：
文献类型：
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作者：
ACKERMANN, U;IRIZAWA, TG;SONNENBERG, H
将Sprague-Dawley大鼠心房或心室组织提取物注射到经inactin麻醉的实验大鼠体内。与心室提取物相比，心房提取物使平均动脉血压下降20 mm Hg （1 mm Hg = 133.322 Pa [pascal]）。这种下降是由于没有增加心输出量来补偿周围血管舒张。有两个因素导致：心率下降（25次/分钟）和心脏功能未能提高。心脏提取物后心血管参数变化的时间模式和幅度不受先前阿托品化的影响。经迷走神经切除的实验大鼠在心房提取后没有出现心率减慢，平均动脉血压的下降幅度明显小于假迷走神经切除或完整大鼠。另一组实验大鼠在注射提取物前先去迷走神经，去颈窦神经。在这些大鼠中，心房提取物引起的低血压程度明显大于单纯迷走神经切开术后的低血压程度，与神经支配完整的大鼠无显著差异。心房提取物引起的低血压，而不是心室提取物引起的低血压，显然部分是由于迷走神经传入直接刺激化学敏感的心肺受体的反射作用，部分是由于压力感受器卸载的反射作用。心室提取物对各组大鼠均无降压作用。
Tissue extracts derived from atria or ventricles of Sprague-Dawley rats were injected into Inactin-anesthetized assay rats. Compared with ventricular extracts, atrial extracts produced a 20 mm Hg (1 mm Hg = 133.322 Pa [pascal]) fall in mean arterial blood pressure. This fall resulted from failure to increase cardiac output in compensation for peripheral vasodilation. Two factors were responsible: depression of heart rate (by 25 beats/min) and failure to increase cardiac performance. The time patterns and magnitudes of changes in cardiovascular parameters after cardiac extracts were not changed by prior atropinization. Assay rats that were vagotomized showed no cardiac slowing after atrial extract and showed a significantly smaller decrease in mean arterial blood pressure than did sham-vagotomized or intact rats. Another group of assay rats was vagotomized as well as carotid-sinus-denervated before extract injection. In these rats the degree of hypotension caused by atrial extract was significantly greater than that observed after vagotomy alone and was not significantly different from that observed in rats with intact innervation. The hypotension that is caused by atrial extract, but not by ventricular extracts, apparently results in part from the reflex effects of direct stimulation of chemosensitive cardiopulmonary receptors with vagal afferents and partly from the reflex effects of baroreceptor unloading. Ventricular extract had no hypotensive effect in any group of assay rats.