Stubenitsky R, Verdouw P D, Duncker D J
Thoraxcenter, Cardiovascular Research Institute COEUR, Erasmus University Rotterdam, Netherlands.
Cardiovasc Res. 1998 Aug;39(2):459-74. doi: 10.1016/s0008-6363(98)00102-3.
The present study determined the role of the autonomic nervous system (ANS) in the regulation of systemic and pulmonary circulation and of O2 delivery and utilization in swine at rest and during graded treadmill exercise.
Instrumented swine (n = 12) were subjected to treadmill exercise (1-5 km/h) under control conditions and in the presence of single and combined beta-adrenergic, alpha-adrenergic and muscarinic (M) receptor blockade.
Exercise produced a four-fold increase in body O2 consumption, due to a doubling of both cardiac output and the arterio-mixed-venous O2 content difference. The latter resulted from an increase in O2 extraction, from 45 +/- 1% at rest to 74 +/- 1% at 5 km/h, as the O2 carrying capacity [haemoglobin concentration (Hb)] increased by only approximately 10%. The increase in cardiac output resulted from a doubling of the heart rate and a small (< 10%) increase in stroke volume. The mean aortic pressure (MAP) was unchanged, implying a 50% decrease in systemic vascular resistance (P < or = 0.05). In contrast, exercise had no significant effect on pulmonary vascular resistance. The sympathetic division of the ANS controlled O2 delivery via beta-adrenoceptors (heart rate and contractility) and Hb concentration via alpha-adrenoceptor-mediated splenic contraction. In addition, the sympathetic division modulated systemic vascular tone via alpha- and beta-adrenoceptors, but also exerted a vasodilator influence on the pulmonary circulation via beta-adrenoceptors. The parasympathetic division controlled O2 delivery in part directly (heart rate) and in part indirectly via inhibition of beta-adrenoceptor activity (heart rate and contractility), even during heavy exercise. In addition, the parasympathetic division exerted a direct vasodilator influence on the pulmonary, but not on the systemic, circulation.
Thus, in swine, in a manner similar to that in humans, both the sympathetic and parasympathetic division of the ANS contribute to cardiovascular homeostasis during exercise up to levels of high intensity.
本研究确定了自主神经系统（ANS）在静息状态及分级跑步机运动期间对猪的体循环和肺循环以及氧输送与利用的调节作用。
对装有仪器的猪（n = 12）在对照条件下以及在β-肾上腺素能、α-肾上腺素能和毒蕈碱（M）受体单一阻断及联合阻断的情况下进行跑步机运动（1 - 5 km/h）。
运动使机体氧耗增加了四倍，这是由于心输出量和动-混合静脉氧含量差均增加了一倍。后者是由于氧摄取增加所致，从静息时的45±1%增加到5 km/h时的74±1%，而氧携带能力[血红蛋白浓度（Hb）]仅增加了约10%。心输出量的增加是由于心率增加了一倍且每搏输出量有小幅（<10%）增加。平均主动脉压（MAP）未改变，这意味着体循环血管阻力降低了50%（P≤0.05）。相比之下，运动对肺血管阻力无显著影响。ANS的交感神经部分通过β-肾上腺素能受体（心率和收缩力）控制氧输送，并通过α-肾上腺素能受体介导的脾收缩控制Hb浓度。此外，交感神经部分通过α-和β-肾上腺素能受体调节体循环血管张力，但也通过β-肾上腺素能受体对肺循环发挥血管舒张作用。副交感神经部分部分直接（心率）部分间接（通过抑制β-肾上腺素能受体活性，心率和收缩力）控制氧输送，即使在剧烈运动时也是如此。此外，副交感神经部分对肺循环有直接血管舒张作用，但对体循环无此作用。
因此，在猪中，与人类相似，ANS的交感和副交感神经部分在高强度运动水平之前的运动过程中都有助于心血管稳态。
