Effect of sympathectomy on inotropic responsiveness to alpha-adrenoceptor stimulation in developing mouse myocardia.
Effect of sympathectomy on inotropic responsiveness to alpha-adrenoceptor stimulation in developing mouse myocardia.
复制标题
交感神经切除术对发育中小鼠心肌中α-肾上腺素受体刺激的正性肌力反应的影响。
DOI：
10.1139/y95-181
复制
发表时间：
1995
影响因子：
2.1
通讯作者：
K. Shigenobu
中科院分区：
文献类型：
--
作者：
H. Tanaka;T. Matsuda;M. Adachi;K. Shigenobu
本实验观察了生后交感神经切断对小鼠心肌对α-肾上腺素能受体刺激的正性肌力反应的影响，以确定交感神经是否触发了α-肾上腺素能受体介导的正性肌力反应向负性肌力反应的发育性转化。交感神经切除是通过在出生后连续14天给予6-羟基多巴胺进行的，并通过没有对酪胺的变力反应来证实。在新生心肌中，在心得安存在的情况下，苯肾上腺素产生浓度依赖的正性变力反应。出生三周后，在心得安存在的情况下，苯肾上腺素在对照组和去交感神经心肌中均产生浓度依赖的负性变力反应；两组小鼠之间没有观察到苯肾上腺素所产生的最大收缩力量的差异。去交感神经心肌对苯肾上腺素的敏感性(PD2值)显著高于去交感神经节心肌。总之，α-肾上腺素能受体介导的变力反应从阳性到阴性的发育性转化不需要交感神经支配小鼠的心室肌。
Effects of postnatal sympathectomy on inotropic responsiveness to alpha-adrenoceptor stimulation were examined in mouse myocardia to determine whether the developmental conversion of alpha-adrenoceptor-mediated inotropic responses from positive to negative is triggered by sympathetic innervation. Sympathectomy was performed chemically by consecutively administering 6-hydroxydopamine for 14 days after birth and confirmed by the absence of inotropic responses to tyramine. In newborn myocardia, phenylephrine, in the presence of propranolol, produced concentration-dependent positive inotropic responses. Three weeks after birth, phenylephrine, in the presence of propranolol, produced concentration-dependent negative inotropic responses, both in control and in sympathectomized myocardia; no difference was observed between the two groups of mice in the maximum decrease in contractile force produced by phenylephrine. The sensitivity (pD2 value) to phenylephrine was significantly higher in sympathectomized myocardia. In conclusion, sympathetic innervation of the mouse ventricular myocardium is not required for the developmental conversion of the alpha-adrenoceptor-mediated inotropic response from positive to negative.