Maciel B C, Gallo L, Marin-Neto J A, Terra-Filho J, Manço J C
Braz J Med Biol Res. 1985;18(3):303-8.
The effect of parasympathetic blockade with intravenously administered atropine (0.04 mg/kg body weight) on the heart rate (HR) of 11 normal males was evaluated using a standardized isometric exercise (handgrip). This type of exercise, when maintained for 10 s at the maximum intensity tolerated by the volunteer, causes tachycardia mediated almost exclusively by parasympathetic withdrawal. The test was performed under baseline conditions and at 20 +/- 3, 33 +/- 3, 42 +/- 3, 52 +/- 3 and 61 +/- 3 min after atropine infusion. The heart rate of the subjects at rest in the supine position (mean +/- SEM) was 70 +/- 2 bpm, reaching values of 119 +/- 3 bpm after atropine. Under control conditions (sitting position), the increase in HR induced by isometric exercise was 22 +/- 1.8 bpm. After blockade, the increase was 4 +/- 0.8, 4 +/- 0.7, 5 +/- 0.6, 4 +/- 1.0 and 4 +/- 0.8 bpm, respectively, at each repetition of the test. These results suggest that the blockade induced by this dose of atropine is effective for at least 1 h. They also indicate the need for a more rigorous definition of the functional half-life of atropine in the heart, when considering physiological tests that either stimulate or withdraw parasympathetic activity upon the heart.
采用标准化等长运动（握力）评估静脉注射阿托品（0.04mg/kg体重）对11名正常男性心率（HR）的副交感神经阻滞作用。这种运动在志愿者所能耐受的最大强度下持续10秒，几乎完全通过副交感神经撤回来引起心动过速。该测试在基线条件下以及阿托品输注后20±3、33±3、42±3、52±3和61±3分钟进行。受试者仰卧位休息时的心率（平均值±标准误）为70±2次/分钟，阿托品注射后达到119±3次/分钟。在对照条件下（坐位），等长运动引起的心率增加为22±1.8次/分钟。阻断后，每次重复测试时心率增加分别为4±0.8、4±0.7、5±0.6、4±1.0和4±0.8次/分钟。这些结果表明，该剂量阿托品引起的阻滞至少持续1小时有效。当考虑对心脏进行刺激或撤回副交感神经活动的生理测试时，这些结果还表明需要更严格地定义阿托品在心脏中的功能半衰期。
