The impact of adenosine and an A2A adenosine receptor agonist on the ACh-induced increase in intracellular calcium of the glomus cells of the cat carotid body.
The impact of adenosine and an A2A adenosine receptor agonist on the ACh-induced increase in intracellular calcium of the glomus cells of the cat carotid body.
复制标题
腺苷和A2A腺苷受体激动剂对ACH诱导的猫颈体肾小球细胞细胞内钙的增加的影响。
DOI：
10.1016/j.brainres.2009.08.100
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发表时间：
2009-12-08
期刊：
影响因子：
2.9
通讯作者：
Chang, Irene
中科院分区：
文献类型：
--
作者：
Fitzgerald, Robert S.;Shirahata, Machiko;Chang, Irene
颈动脉体（CB）是位于颈内动脉旁边的动脉血的多模态化学传感器。化学感受的基本单位是由含有神经递质（NT）的血管球细胞（GC）和与其形成突触的感觉传入纤维组成。在感觉传入纤维和GC上都发现了烟碱和毒蕈碱受体。当灌注CB的动脉血处于缺氧、低血糖、高碳酸血症或酸性时，来自CB的神经输出（CBNO）增加。由于兴奋性NT的GC释放引起的CBNO增加必须由钙进入GC之前。随着ACh从GC的反复释放，胆碱能受体可以变得脱敏，特别是作为钙通道的烟碱受体。本研究的目的是，看看腺苷（ADO），已知改变受体的敏感性，可以减弱或消除任何脱敏的烟碱受体发生在ACh的重复应用。猫CB是采用大学动物护理/使用委员会批准的技术收获的。培养GC并制备用于用标准技术检测[Ca++]i。反复应用ACh使[Ca++]i逐渐降低。通过使用ADO或A2 a ADO受体激动剂，避免了降低。虽然ADO也增加GC [Ca++]i，但单独灌流时，ADO增加和ACh增加的总和小于它们都包含在同一灌流中时的增加。这意味着行动中可能涉及一条新的道路。解释的现象的潜在机制进行了讨论。
The carotid body (CB) is a polymodal chemosensor of arterial blood located next to the internal carotid artery. The basic chemosensing unit is composed of the neurotransmitter (NT)-containing glomus cells (GCs) and the sensory afferent fibers synapsing onto the GCs. Nicotinic and muscarinic receptors have been found on both the sensory afferent fibers and on the GCs. Neural output from the CB (CBNO) increases when arterial blood perfusing it is hypoxic, hypoglycemic, hypercapnic, or acidic. The increased CBNO due to GC release of excitatory NTs must be preceded by an entrance of calcium into the GCs. With repeated release of ACh from the GCs, cholinergic receptors could become desensitized, particularly nicotinic receptors which function as calcium channels. The purpose of the present study was to see if adenosine (ADO), known to alter receptor sensitivities, could attenuate or eliminate any desensitization of the nicotinic receptors occurring during the repeated application of ACh. Cat CBs were harvested with techniques approved by the University's Animal Care/Use Committee. The GCs were cultured and prepared for detecting [Ca++]i with standard techniques. Repeated application of ACh produced a progressively decreasing increase in [Ca++]i. With the use of ADO or an A2a ADO receptor agonist the decrease was avoided. Though ADO also increased GC [Ca++]i, the sum of ADO increase and ACh increase, when superfused separately, was less than the increase when they were both included in the same superfusion. This suggested the possible involvement of a new path in the action. Potential mechanisms to explain the phenomena are discussed.
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影响因子：
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