Jovanovic A, Jovanovic S, Mays D C, Lipsky J J, Terzic A
Department of Medicine, Mayo Clinic, Mayo Foundation, Rochester, MN 55905, USA.
FEBS Lett. 1998 Feb 27;423(3):314-8. doi: 10.1016/s0014-5793(98)00114-8.
Dinucleotide polyphosphates (ApnA) have emerged as signaling molecules in rapidly dividing cells. The presence and role of Ap5A in the heart remain unknown. Here, we report that the myocardium contains abundant amounts of diadenosine 5',5"-P1,P5-pentaphosphate (Ap5A), a member of the ApnA family. Ischemia induced 10-fold decrease in the myocardial concentration of Ap5A. A target of Ap5A action was identified to be the cardiac ATP-sensitive K+ (K(ATP)) channel, a metabolism-sensitive ion conductance activated in ischemia. At levels found in hearts prior to ischemia, Ap5A maintained a low probability of K(ATP) channel opening, but at levels found in hearts following ischemia, Ap5A allowed a high probability of K(ATP) channel opening. Taken together, the present data suggest that Ap5A harbors the properties of a signaling molecule involved in the cardiac response to metabolic stress.
二核苷酸多磷酸（ApnA）已成为快速分裂细胞中的信号分子。Ap5A在心脏中的存在及作用尚不清楚。在此，我们报告心肌中含有大量的5',5"-P1,P5-五磷酸二腺苷（Ap5A），它是ApnA家族的一员。缺血导致心肌中Ap5A浓度下降10倍。Ap5A的作用靶点被确定为心脏ATP敏感性钾（K(ATP)）通道，这是一种在缺血时被激活的代谢敏感性离子通道。在缺血前心脏中发现的水平下，Ap5A使K(ATP)通道开放的概率维持在低水平，但在缺血后心脏中发现的水平下，Ap5A使K(ATP)通道开放的概率较高。综上所述，目前的数据表明Ap5A具有参与心脏对代谢应激反应的信号分子特性。
