Armiger L C, Knell C M
Department of Pathology, University of Auckland, School of Medicine, New Zealand.
Exp Pathol. 1989;36(2):105-12. doi: 10.1016/s0232-1513(89)80125-2.
The sinus node of the dog was examined, using a large-specimen resin-embedding method for combined light and electron microscopy, after 30-240 min of total in vitro ischaemia and after 15-180 min of reduced blood flow in hearts with 2:1 AV block. Although progressive fine structural alteration was observed in the in vitro series, not all cells developed changes at the same rate. Complete loss of glycogen stores and swelling of organelles could be seen in many after only 30 min, whilst others retained their glycogen and showed minimal alteration even after 90 min. Despite relatively severe alteration throughout the node after 120 or more min, some groups of cells showed more extreme degrees of swelling and surface bleb formation than others. In the partially ischaemic in vivo series focal alteration, consisting chiefly of mitochondrial swelling and/or gross dilatation of sarcoplasmic reticulum vesicles, was detectable after 20 min and increased little in extent or degree during longer periods of reduced blood flow. This non-uniform response of sinus nodal cells to ischaemic injury parallels that of contractile atrial muscle cells.
采用大标本树脂包埋法进行光镜和电镜联合检查，对犬的窦房结进行观察。实验对象为完全体外缺血30 - 240分钟后的心脏，以及存在2:1房室传导阻滞且血流减少15 - 180分钟后的心脏。尽管在体外实验系列中观察到了渐进性的细微结构改变，但并非所有细胞都以相同的速率发生变化。仅30分钟后，许多细胞就可见糖原储备完全丧失和细胞器肿胀，而其他细胞即使在90分钟后仍保留糖原且变化极小。尽管120分钟及更长时间后整个窦房结发生了相对严重的改变，但某些细胞群比其他细胞群表现出更严重的肿胀程度和表面气泡形成。在部分缺血的体内实验系列中，主要由线粒体肿胀和/或肌浆网小泡明显扩张组成的局灶性改变，在血流减少20分钟后即可检测到，且在更长时间的血流减少过程中，其范围或程度增加很少。窦房结细胞对缺血损伤的这种不均匀反应与收缩性心房肌细胞的反应相似。
