Walker J L, Thames M D, Abboud F M, Mark A L, Klopfenstein H S
Am J Physiol. 1978 Aug;235(2):H188-92. doi: 10.1152/ajpheart.1978.235.2.H188.
The purpose of this study was to determine the relative magnitudes of the reflex effects mediated by sensory endings in the left ventricle activated by intracoronary injection of nicotine or veratridine into left anterior descending (LAD) or circumflex (Cx) coronary arteries in the dog. Injection of nicotine or veratridine into the Cx consistently resulted in larger decreases in heart rate, arterial pressure, and in gracilis perfusion pressure than were observed following injection of the same dose into the LAD. Vagotomy abolished the cardioinhibitory and vasodepressor responses to intracoronary nicotine or veratridine. The weight of left ventricle perfused by LAD or Cx was not different (43.5 +/- 1.65 and 44.5 +/- 2.2 g, respectively. These data indicate that chemical activation of sensory endings with vagal afferents in the inferoposterior left ventricle of the dog results in larger cardionhibitor and vasodepressor responses than result from activation of respects in the anterior left ventricle. Further, these data provide strong evidence that these sensory endings which are chemically activated are preferentially distributed to the inferoposterior left ventricle.
本研究的目的是确定通过向犬左前降支（LAD）或回旋支（Cx）冠状动脉内注射尼古丁或藜芦碱激活左心室内感觉末梢所介导的反射效应的相对大小。向Cx注射尼古丁或藜芦碱后，与向LAD注射相同剂量相比，心率、动脉压和股薄肌灌注压的降低幅度始终更大。迷走神经切断术消除了对冠状动脉内尼古丁或藜芦碱的心脏抑制和血管减压反应。由LAD或Cx灌注的左心室重量无差异（分别为43.5±1.65克和44.5±2.2克）。这些数据表明，犬左心室下后壁中具有迷走神经传入纤维的感觉末梢的化学激活，比左心室前壁中相应部位的激活产生更大的心脏抑制和血管减压反应。此外，这些数据提供了有力证据，即这些被化学激活的感觉末梢优先分布于左心室下后壁。
