Bian X, Williams A G, Gwirtz P A, Downey H F
Department of Integrative Physiology, University of North Texas Health Science Center at Fort Worth, Fort Worth, Texas 76107, USA.
Am J Physiol. 1998 Jul;275(1):H169-75. doi: 10.1152/ajpheart.1998.275.1.H169.
Right coronary (RC) autoregulation and right ventricular (RV) function were assessed in conscious dogs, chronically instrumented to measure RC flow and RC pressure (RCP) as a hydraulic occluder on the RC was inflated. Dogs were then anesthetized, and RC autoregulation and RV function were again assessed. In the conscious state, moderate RC autoregulation was present with closed loop gains (Gc) of 0.59-0.27 as RCP was reduced from 100 to 40 mmHg. In the anesthetized state, Gc was not significantly less than in the conscious state at RCP >50 mmHg. The range and potency of RV autoregulation were greater in both groups than for previously reported findings in anesthetized dogs with RC perfused by an extracorporeal system. RV contractile function was well maintained in conscious and anesthetized dogs at RCP >45 mmHg. We conclude the following: 1) modest RC autoregulation is present in the conscious dog, 2) anesthesia limits the range but not the degree of RC autoregulation, 3) extracorporeal perfusion systems appear to depress RC autoregulation, and 4) RV contractile function remains constant in both conscious and anesthetized dogs until RCP falls below 50 mmHg.
在清醒犬中评估右冠状动脉（RC）的自动调节功能和右心室（RV）功能，这些犬长期植入仪器以测量RC血流和RC压力（RCP），同时在RC上充气一个液压阻塞器。然后对犬进行麻醉，并再次评估RC自动调节功能和RV功能。在清醒状态下，当RCP从100 mmHg降至40 mmHg时，存在适度的RC自动调节，闭环增益（Gc）为0.59 - 0.27。在麻醉状态下，当RCP > 50 mmHg时，Gc并不显著低于清醒状态。两组中RV自动调节的范围和效能均大于先前报道的体外系统灌注RC的麻醉犬的研究结果。当RCP > 45 mmHg时，清醒和麻醉犬的RV收缩功能均得到良好维持。我们得出以下结论：1）清醒犬存在适度的RC自动调节；2）麻醉限制了RC自动调节的范围，但不影响其程度；3）体外灌注系统似乎会抑制RC自动调节；4）在清醒和麻醉犬中，直到RCP降至50 mmHg以下，RV收缩功能均保持恒定。
