Tsukada T, Rubio R, Berne R M
J Auton Nerv Syst. 1985 May;13(1):49-64. doi: 10.1016/0165-1838(85)90005-0.
We have hypothesized that the well-established regional heterogeneity of the properties of the vascular smooth muscle results from peculiarities of the microenvironment in every region. In particular, the coronary vasculature has well-established differences between large and small coronary arteries in their responsiveness to alpha and beta agonists, nitroglycerin and adenosine. To test our hypothesis, we altered the micro-environment of coronary vessels by chronic surgical sympathectomy in dogs. Our in vitro studies on vessels from normally innervated hearts confirmed previous studies and showed that in large vessels, alpha and beta epinephrine or norepinephrine responses can be demonstrated; the alpha effect is dominant and epinephrine is a more potent alpha agonist than is norepinephrine. In small vessels only a beta catecholamine effect can be demonstrated. Chronically sympathectomized blood vessels show an alpha norepinephrine effect in small vessels. Denervation caused a reduction in the sensitivity to K+-induced contraction in both large and small vessels. In large vessels the responses to nitroglycerin were not affected by denervation, whereas in small vessels the sensitivity to adenosine was reduced. These results indicate that chronic denervation alters the pharmacological responsiveness of the vasculature to various agonists indicating that vascular smooth muscle possesses the ability to respond to long-term modulatory influences arising in the immediate environment.
我们已经提出假设，即血管平滑肌特性中已确定的区域异质性是由每个区域微环境的特殊性导致的。特别是，冠状动脉系统中，大、小冠状动脉在对α和β激动剂、硝酸甘油及腺苷的反应性方面存在已确定的差异。为了验证我们的假设，我们通过对犬进行慢性手术交感神经切除术来改变冠状动脉的微环境。我们对来自正常有神经支配心脏的血管进行的体外研究证实了先前的研究，并表明在大血管中，可以证明存在α和β肾上腺素或去甲肾上腺素反应；α效应占主导，且肾上腺素作为α激动剂比去甲肾上腺素更有效。在小血管中，仅能证明存在β儿茶酚胺效应。慢性交感神经切除的血管在小血管中显示出去甲肾上腺素的α效应。去神经支配导致大、小血管对钾离子诱导收缩的敏感性降低。在大血管中，对硝酸甘油的反应不受去神经支配的影响，而在小血管中，对腺苷的敏感性降低。这些结果表明，慢性去神经支配改变了血管系统对各种激动剂的药理反应性，表明血管平滑肌具有对直接环境中产生的长期调节影响作出反应的能力。
