Zhang H, Holden A V, Boyett M R
School of Biomedical Sciences, University of Leeds, Leeds, UK.
Circulation. 2001 Jan 30;103(4):584-8. doi: 10.1161/01.cir.103.4.584.
A radical reinterpretation (mosaic model) of the makeup of the sinoatrial (SA) node has been proposed to explain the characteristic regional differences in electrical activity between the periphery and center of the SA node. According to the mosaic model, the differences result from a change in the mix of atrial cells and uniform SA node cells from periphery to center, whereas according to the alternative gradient model, there are no atrial cells within the functional SA node, and the differences result from a change in the intrinsic properties of SA node cells from periphery to center.
A mosaic model of peripheral and central tissue has been constructed computationally by use of a coupled ordinary differential equation network (CODE) in a 2D lattice (20x20), with each node of the lattice designated randomly as an atrial cell or SA node cell (in correct proportions for periphery and center). The mosaic model fails to predict the characteristic differences in action potential rate and shape between the periphery and center, whereas the existing gradient model can do so.
The mosaic model of the SA node is untenable, and the SA node is adequately described by the gradient model.
已提出对窦房（SA）结组成的一种彻底重新解释（镶嵌模型），以解释SA结外周和中心之间电活动的特征性区域差异。根据镶嵌模型，这些差异源于从外周到中心心房细胞和均匀的SA结细胞混合比例的变化，而根据另一种梯度模型，在功能性SA结内不存在心房细胞，差异源于SA结细胞从外周到中心固有特性的变化。
通过在二维晶格（20×20）中使用耦合常微分方程网络（CODE），以计算方式构建了外周和中心组织的镶嵌模型，晶格的每个节点随机指定为心房细胞或SA结细胞（外周和中心比例正确）。镶嵌模型无法预测外周和中心之间动作电位速率和形状的特征差异，而现有的梯度模型可以做到。
SA结的镶嵌模型站不住脚，SA结可用梯度模型充分描述。
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