Department of Environmental Health Sciences (Division of Physiology), The Johns Hopkins Medical Institutions, Baltimore, MD 21205, USA.
Respir Physiol Neurobiol. 2011 May 31;176(3):80-9. doi: 10.1016/j.resp.2011.01.010. Epub 2011 Feb 1.
Do cat carotid bodies (CBs) increase their release of acetylcholine and ATP in response to H(2)S? Two CBs, incubated in a Krebs Ringer bicarbonate solution at 37 ° C, exhibited a normal response to hypoxia-increased release of acetylcholine (ACh) and ATP. They were challenged with several concentrations of Na(2)S, an H(2)S donor. H(2)S, a new gasotransmitter, is reported to open K(ATP) channels. Under normoxic conditions the CBs reduced their release of ACh and ATP below control values. They responded identically to pinacidil, a well-known K(ATP) channel opener. CB glomus cells exhibited a positive immunohistochemical signal for cystathione-β-synthetase, a H(2)S synthesizing enzyme, and for a subunit of the K(ATP) channel. The data suggest that Na(2)S may have opened the glomus cells' K(ATP) channels, hyperpolarizing the cells, thus reducing their tonic release of ACh and ATP. Since during hypoxia H(2)S levels rise, the glomus cells responding very actively to hypoxia may be protected from over-exertion by the H(2)S opening of the K(ATP) channels.
猫颈动脉体（CBs）是否会响应 H（2）S 增加乙酰胆碱和 ATP 的释放？在 37°C 的 Krebs 缓冲盐溶液中孵育的两个 CB 对缺氧引起的乙酰胆碱（ACh）和 ATP 释放增加表现出正常反应。它们受到几种浓度的 Na（2）S（H（2）S 供体）的挑战。H（2）S，一种新的气体递质，据报道可打开 K（ATP）通道。在正常氧合条件下，CB 降低了 ACh 和 ATP 的释放，低于对照值。它们对 pinacidil（一种众所周知的 K（ATP）通道开放剂）的反应相同。CB 球细胞表现出半胱氨酸-β-合酶（一种 H（2）S 合成酶）和 K（ATP）通道亚基的阳性免疫组织化学信号。数据表明，Na（2）S 可能打开了球细胞的 K（ATP）通道，使细胞超极化，从而减少其 ACh 和 ATP 的紧张性释放。由于在缺氧期间 H（2）S 水平升高，对缺氧反应非常活跃的球细胞可能会受到 H（2）S 打开 K（ATP）通道的保护，以免过度劳累。
