Acute arterial baroreflex-mediated changes in plasma catecholamine concentrations in a chronic rat model of myocardial infarction.
Acute arterial baroreflex-mediated changes in plasma catecholamine concentrations in a chronic rat model of myocardial infarction.
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DOI：
10.14814/phy2.12880
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发表时间：
2016-08
影响因子：
2.5
通讯作者：
Sugimachi M
中科院分区：
文献类型：
--
作者：
Kawada T;Akiyama T;Li M;Zheng C;Turner MJ;Shirai M;Sugimachi M
当压力感受器压力输入时，血浆去甲肾上腺素(NE)浓度随着传出交感神经活动(SNA)的变化是可以预测的，但SNA和血浆NE浓度之间的确切关系在心力衰竭中仍有待量化。我们检测了正常对照组(NC)和心肌梗死(MI)大鼠(n=6)血浆去甲肾上腺素(NE)和肾上腺素(Epi)浓度的急性压力感受性反射的变化。NC组血浆NE浓度与SNA呈线性相关(斜率：2.17±0.26pg/mL−1%−1，截距：20.0±18.2pg/mL−1)，MI组血浆NE浓度与SNA呈线性相关(斜率：19.20±6.45pg/mL−1%−1，截距：−239.6±200.0 pg/mL−1)。MI组的斜率大约是NC组的9倍(P<0.01)。NC组血浆EPI浓度与SNA呈正相关(斜率：1.65±0.79 pg/mL−1%−1，截距：115.0±69.5 pg/mL−1)，MI组血浆EPI浓度与SNA呈正相关(斜率：7.74±2.20 pg/mL−1%−1，截距：24.70±120.1 pg/mL−1)。心肌梗死组的斜率约为NC组的4.5倍(P<0.05)。静脉注射地昔帕明(1 mg/kg−-1)后，两组大鼠血浆NE浓度均显著升高，而血浆EPI浓度显著降低，提示神经元对NE的摄取参与了血浆NE浓度的降低。这些结果表明，MI大鼠血浆儿茶酚胺水平的升高仍然受到压力感受器介导的SNA变化的影响，这可能为慢性心力衰竭患者应用压力感受器激活疗法提供了额外的理论依据。
While it may be predictable that plasma norepinephrine (NE) concentration changes with efferent sympathetic nerve activity (SNA) in response to baroreceptor pressure inputs, an exact relationship between SNA and plasma NE concentration remains to be quantified in heart failure. We examined acute baroreflex‐mediated changes in plasma NE and epinephrine (Epi) concentrations in normal control (NC) rats and rats with myocardial infarction (MI) (n = 6 each). Plasma NE concentration correlated linearly with SNA in the NC group (slope: 2.17 ± 0.26 pg mL−1 %−1, intercept: 20.0 ± 18.2 pg mL−1) and also in the MI group (slope: 19.20 ± 6.45 pg mL−1 %−1, intercept: −239.6 ± 200.0 pg mL−1). The slope was approximately nine times higher in the MI than in the NC group (P < 0.01). Plasma Epi concentration positively correlated with SNA in the NC group (slope: 1.65 ± 0.79 pg mL−1 %−1, intercept: 115.0 ± 69.5 pg mL−1) and also in the MI group (slope: 7.74 ± 2.20 pg mL−1 %−1, intercept: 24.7 ± 120.1 pg mL−1). The slope was approximately 4.5 times higher in the MI than in the NC group (P < 0.05). Intravenous administration of desipramine (1 mg kg−1) significantly increased plasma NE concentration but decreased plasma Epi concentration in both groups, suggesting that neuronal NE uptake had contributed to the reduction in plasma NE concentration. These results indicate that high levels of plasma catecholamine in MI rats were still under the influence of baroreflex‐mediated changes in SNA, and may provide additional rationale for applying baroreflex activation therapy in patients with chronic heart failure.