Freeman G L, Colston J T, Hultman J
Department of Medicine, University of Texas Health Science Center, San Antonio.
Am J Physiol. 1990 Feb;258(2 Pt 2):H424-30. doi: 10.1152/ajpheart.1990.258.2.H424.
Adenosine, a potent vasodilator of both the peripheral and coronary vasculature, is increasingly used to produce controlled hypotension in the clinical and experimental setting. To define the influence of adenosine on left ventricular (LV) performance in conscious closed-chest dogs were studied six chronically instrumented autonomically blocked animals before and after the administration of 0.3, 0.6, and 1.2 microM.kg-1.min-1 infusions of adenosine. Systolic performance was quantified by the end-systolic pressure-volume (Pes-Ves) and stroke work end-diastolic volume (SW-EDV) relations. Active diastolic performance was quantified by the time constant of LV relaxation (T), whereas passive diastolic properties were assessed by comparing LV pressures at a common LV volume. Despite a decrease of mean arterial pressure of 51 mmHg, adenosine did not change the slope of the Pes-Ves relation or the end-systolic volume at a pressure of 100 mmHg. The slope of the SW-EDV relation was also unchanged, and its volume axis intercept was slightly reduced. There were no differences in T or in the diastolic pressure at a common LV volume. Thus adenosine appears to have little influence on systolic or diastolic LV performance aside from its marked affect on afterload, indicating it is a useful agent for producing controlled hypotension.
腺苷是一种对周围血管和冠状动脉均有强效扩张作用的血管扩张剂，在临床和实验环境中越来越多地被用于产生控制性低血压。为了确定腺苷对清醒闭胸犬左心室（LV）功能的影响，对6只长期植入仪器且自主神经被阻断的动物在输注0.3、0.6和1.2微摩尔/千克-1·分钟-1腺苷之前和之后进行了研究。收缩功能通过收缩末期压力-容积（Pes-Ves）和每搏功-舒张末期容积（SW-EDV）关系进行量化。主动舒张功能通过左心室舒张时间常数（T）进行量化，而被动舒张特性则通过比较相同左心室容积下的左心室压力来评估。尽管平均动脉压降低了51 mmHg，但腺苷并未改变Pes-Ves关系的斜率或100 mmHg压力下的收缩末期容积。SW-EDV关系的斜率也未改变，其容积轴截距略有降低。在相同左心室容积下，T或舒张压没有差异。因此，除了对后负荷有显著影响外，腺苷似乎对左心室的收缩或舒张功能影响很小，这表明它是产生控制性低血压的有用药物。
