Department of Pharmacology, Jikei University School of Medicine, 3-25-8 Nishi-shimbashi, Minato-ku, Tokyo 105-8461, Japan.
Cell Calcium. 2011 Apr;49(4):249-58. doi: 10.1016/j.ceca.2011.02.009. Epub 2011 Mar 12.
It is well established that astrocytes release gliotransmitters and moderate neuronal activity in the central nervous system via intracellular Ca(2+) dynamics. Astrocytic Ca(2+) oscillations are one type of spontaneous Ca(2+) mobilization that occurs in astrocytes. However, the modulation of spontaneous astrocytic Ca(2+) oscillations, especially in pathophysiological conditions, is not yet fully understood. Here, we demonstrate that activation of adenosine receptors induces a long-lasting increase in the frequency of astrocytic Ca(2+) oscillations in rat hippocampal slice cultures. The long-term facilitation of the frequency of Ca(2+) oscillations was mediated by endogenous adenosine generated via breakdown of extracellular ATP by ecto-ATPase. We also demonstrate that local tissue injury with ultraviolet irradiation can cause this long-term facilitation of Ca(2+) oscillations via endogenous adenosine. Our data suggest that endogenous adenosine is one of the modulators of spontaneous astrocytic Ca(2+) oscillations in the rat hippocampus, and may play a significant role in altered Ca(2+) dynamics in astrocytes observed during pathophysiological conditions.
已有充分证据表明，星形胶质细胞通过细胞内 Ca(2+) 动力学释放神经递质并调节中枢神经系统中的神经元活动。星形胶质细胞 Ca(2+) 振荡是星形胶质细胞中发生的一种自发 Ca(2+) 动员形式。然而，自发星形胶质细胞 Ca(2+) 振荡的调节，特别是在病理生理条件下，尚未完全了解。在这里，我们证明激活腺苷受体可诱导大鼠海马切片培养物中星形胶质细胞 Ca(2+) 振荡的频率长时间增加。Ca(2+) 振荡频率的长期易化是通过细胞外 ATP 通过胞外 ATP 酶分解产生的内源性腺苷介导的。我们还证明，紫外线照射造成的局部组织损伤可通过内源性腺苷引起 Ca(2+) 振荡的这种长期易化。我们的数据表明，内源性腺苷是大鼠海马中自发星形胶质细胞 Ca(2+) 振荡的调节剂之一，并且可能在病理生理条件下观察到的星形胶质细胞中 Ca(2+) 动力学改变中发挥重要作用。
