Jankord Ryan, McAllister Richard M, Ganjam Venkataseshu K, Laughlin M Harold
Dept. of Psychiatry, Univ. of Cincinnati, Genome Research Institute, OH 45237, USA.
Am J Physiol Regul Integr Comp Physiol. 2009 Mar;296(3):R728-34. doi: 10.1152/ajpregu.90709.2008. Epub 2009 Jan 14.
Exercise can activate the hypothalamo-pituitary-adrenocortical (HPA) axis, and regular exercise training can impact how the HPA axis responds to stress. The mechanism by which acute exercise induces HPA activity is unclear. Therefore, the purpose of this study was to test the hypothesis that nitric oxide modulates the neuroendocrine component of the HPA axis during exercise. Female Yucatan miniature swine were treated with N-nitro-l-arginine methyl ester (l-NAME) to test the effect of chronic nitric oxide synthase (NOS) inhibition on the ACTH response to exercise. In addition, we tested the effect of NOS inhibition on blood flow to tissues of the HPA axis and report the effects of handling and treadmill exercise on the plasma concentrations of ACTH and cortisol. Chronic NOS inhibition decreased plasma NO(x) levels by 44%, increased mean arterial blood pressure by 46%, and increased expression of neuronal NOS in carotid arteries. Vascular conductance was decreased in the frontal cortex, the hypothalamus, and the adrenal gland. Chronic NOS inhibition exaggerated the ACTH response to exercise. In contrast, chronic NOS inhibition decreased the ACTH response to restraint, suggesting that the role of NO in modulating HPA activity is stressor dependent. These results demonstrate that NOS activity modulates the response of the neuroendocrine component of the HPA axis during exercise stress.
运动可激活下丘脑 - 垂体 - 肾上腺皮质（HPA）轴，而规律的运动训练会影响HPA轴对应激的反应。急性运动诱导HPA轴活动的机制尚不清楚。因此，本研究的目的是检验一氧化氮在运动过程中调节HPA轴神经内分泌成分的这一假说。对雌性尤卡坦小型猪使用N - 硝基 - l - 精氨酸甲酯（l - NAME）来测试慢性一氧化氮合酶（NOS）抑制对促肾上腺皮质激素（ACTH）运动反应的影响。此外，我们测试了NOS抑制对HPA轴组织血流的影响，并报告了处理和跑步机运动对ACTH和皮质醇血浆浓度的影响。慢性NOS抑制使血浆NO(x)水平降低了44%，平均动脉血压升高了46%，并增加了颈动脉中神经元型NOS的表达。额叶皮质、下丘脑和肾上腺的血管传导性降低。慢性NOS抑制增强了ACTH对运动的反应。相反，慢性NOS抑制降低了ACTH对束缚的反应，表明NO在调节HPA轴活动中的作用取决于应激源。这些结果表明，NOS活性在运动应激期间调节HPA轴神经内分泌成分的反应。
