Watters T, Wikman-Coffelt J, Wu S, James T L, Sievers R, Parmley W W
Department of Medicine, University of California, San Francisco 94143.
Hypertension. 1989 May;13(5):480-8. doi: 10.1161/01.hyp.13.5.480.
A chemomechanical study of hypertrophied hearts of 6-month-old spontaneously hypertensive rats (SHR) and that of age-matched Wistar-Kyoto (WKY) rats was carried out, analyzing the response of the heart to steady-state changes in coronary perfusion pressure. The ratio of heart (dry)-to-body (wet) weight of WKY rats was 0.37 +/- 0.02 (10(-3] and for SHR was 0.58 +/- 0.03 (10(-3] (p less than 0.01). In the apex-ejecting, isolated, pyruvate-perfused working hearts of WKY rats and SHR, coronary flow was constant when coronary perfusion pressure was set between 140 and 190 cm H2O (range of autoregulation). Coronary flow was perfusion pressure dependent when the coronary perfusion pressure was set below 110 cm H2O for both WKY rats and SHR. Cardiac output, developed pressure, rate of pressure development (dP/dt), and oxygen consumption were constant in the range of autoregulation but decreased in the direction of coronary flow when coronary flow was reduced by a drop in perfusion pressure. Similarly, the phosphorylation potential, phosphocreatine, adenosine triphosphate, and cyclic adenosine monophosphate were constant in the range of autoregulation but decreased directionally with coronary perfusion pressure below 110 cm H2O for both SHR and WKY rats. There was a significantly lower phosphorylation potential in SHR as compared with WKY rats when coronary perfusion pressure was reduced to 80 cm H2O. In the region of autoregulation, coronary flow and oxygen consumption were significantly less in SHR, although developed pressure was significantly greater at both high and low workloads.(ABSTRACT TRUNCATED AT 250 WORDS)
对6月龄自发性高血压大鼠（SHR）和年龄匹配的Wistar-Kyoto（WKY）大鼠的肥厚心脏进行了化学机械研究，分析心脏对冠状动脉灌注压稳态变化的反应。WKY大鼠心脏（干重）与体重（湿重）之比为0.37±0.02（10⁻³），SHR为0.58±0.03（10⁻³）（p<0.01）。在WKY大鼠和SHR的心尖射出、离体、丙酮酸灌注的工作心脏中，当冠状动脉灌注压设定在140至190 cm H₂O之间（自动调节范围）时，冠状动脉血流量恒定。当冠状动脉灌注压设定低于110 cm H₂O时，WKY大鼠和SHR的冠状动脉血流量均依赖于灌注压。心输出量、发育压力、压力上升速率（dP/dt）和氧耗在自动调节范围内恒定，但当冠状动脉血流量因灌注压下降而减少时，它们会随着冠状动脉血流量的减少而下降。同样，磷酸化电位、磷酸肌酸、三磷酸腺苷和环磷酸腺苷在自动调节范围内恒定，但当冠状动脉灌注压低于110 cm H₂O时，SHR和WKY大鼠的这些指标均会随冠状动脉灌注压呈方向性下降。当冠状动脉灌注压降至80 cm H₂O时，SHR的磷酸化电位显著低于WKY大鼠。在自动调节区域，SHR的冠状动脉血流量和氧耗显著较低，尽管在高负荷和低负荷下发育压力均显著较高。（摘要截断于250字）
