McCallister L P, Liedtke A J, Hughes H C
J Thorac Cardiovasc Surg. 1979 May;77(5):647-61.
The conducting system was studied in an in situ perfused swine heart preparation with reduced coronary flow (ischemia) using perfusate containing high and low levels of glucose (26.6 versus 8.6mM) with and without insulin. Coronary flow was maintained at normal levels for 60 minutes in control hearts. In ischemic hearts flow was reduced to about 50 percent of control levels for 30 minutes. Ultrastructural studies documented only subtle modifications of Purkinje fibers in ischemic hearts. Glycogen depletion and disruption of cell junctions were observed in some fibers. One consistent finding was the activation of the lysosomal system. The outer membranes of primary lysosomes appeared herniated and in some cases disrupted, and small vesicles containing hydrolytic enzymes were seen in association with the Golgi apparatus and larger primary lysosomes. Specimens prepared for the demonstration of acid phosphatase indicated a redistribution of hydrolytic enzymes in Purkinje fibers with a depostion of acid hydrolases in smaller lysosomal vesicles, the transverse and side-to-side junctions between cells, and occasionally in the sarcoplasmic reticulum. Enriched perfusate containing high levels of glucose with insulin appeared to have no therapeutic effects in terms of the structure of the Purkinje fibers. The results suggest that alterations in the lysosomal system may be one of the earliest structural changes which occur in oxygen-deficient hearts.
在一个原位灌注猪心脏标本中，利用含高、低水平葡萄糖（26.6 对 8.6 mM）且添加或不添加胰岛素的灌注液，研究了冠状动脉血流减少（缺血）情况下的传导系统。对照心脏的冠状动脉血流维持在正常水平 60 分钟。缺血心脏的血流在 30 分钟内降至对照水平的约 50%。超微结构研究记录了缺血心脏中浦肯野纤维仅有细微改变。在一些纤维中观察到糖原耗竭和细胞连接的破坏。一个一致的发现是溶酶体系统的激活。初级溶酶体的外膜出现疝出，在某些情况下破裂，并且可见含有水解酶的小泡与高尔基体和较大的初级溶酶体相关联。为显示酸性磷酸酶而制备的标本表明，浦肯野纤维中水解酶重新分布，酸性水解酶沉积在较小的溶酶体小泡、细胞间的横向和侧向连接处，偶尔也沉积在肌浆网中。含高水平葡萄糖并添加胰岛素的富集灌注液在浦肯野纤维结构方面似乎没有治疗作用。结果表明，溶酶体系统的改变可能是缺氧心脏中最早出现的结构变化之一。
