PROPAGATION OF IMPULSES ACROSS PURKINJE FIBER-MUSCLE JUNCTIONS IN DOG HEART
PROPAGATION OF IMPULSES ACROSS PURKINJE FIBER-MUSCLE JUNCTIONS IN DOG HEART
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DOI：
10.1161/01.res.26.2.135
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发表时间：
1970-01-01
影响因子：
20.1
通讯作者：
URGUIAGA, X
中科院分区：
文献类型：
--
作者：
MENDEZ, C;MUELLER, WJ;URGUIAGA, X
在犬浦肯野纤维-乳头肌制剂中，直接表明电紧张传播可以发生在浦肯野纤维和普通肌纤维之间的连接处（P-M 连接处）。在任何给定的准备过程中，顺向传播期间记录的 P-M 延迟变化很大。外部 K+ 浓度的适度增加（高达 6 mM）持续降低 P-M 延迟；当外部K+浓度增加到8 mM时，P-M延迟增加。当 K+ 浓度较高（10 至 11 mM）时，会发生从末端浦肯野纤维到肌肉的完全传导阻滞；在相同条件下，从肌肉到浦肯野纤维的逆向传播仍然是可能的。通过假设穿过 P-M 连接的传播是电的，并且功能性合胞体的几何形状从末端浦肯野纤维水平的电缆状系统逐渐变化为心肌块主体处的二维或三维不规则合胞体，可以令人满意地解释结果。
In canine Purkinje fiber-papillary muscle preparations it was shown directly that electrotonic spread can take place across the junctions between Purkinje fibers and ordinary muscle fibers (P-M junctions). The P-M delay recorded during orthodromic propagation varied considerably within any given preparation. Moderate increases in the external concentration of K+(up to 6 mM) consistently decreased the P-M delay; when the concentration of external K+was increased to 8 mMthe P-M delay increased. With larger concentrations of K+(10 to 11 mM), total conduction block from the terminal Purkinje fibers to the muscle occurred; under the same conditions antidromic propagation from muscle to Purkinje fiber was still possible. The results can be explained satisfactorily by assuming that propagation across the P-M junction is electrical and that the geometry of the functional syncytium changes progressively from a cable-like system at the level of the terminal Purkinje fibers to a two- or three-dimensional irregular syncytium at the bulk of the myocardial mass.