Department of Physiology, Shiga University of Medical Science, Otsu, Shiga 520-2192, Japan.
J Histochem Cytochem. 2010 Jun;58(6):543-51. doi: 10.1369/jhc.2010.955245. Epub 2010 Mar 2.
The present study was designed to examine the postnatal developmental changes of atypically shaped cardiomyocytes (ACMs) prepared from the heart of newborn [postnatal day 1 (day-1)] through aged (12-month-old) mice. ACMs were identified as a novel type of self-beating cardiomyocyte with a peculiar morphology in mouse cardiac ventricles. The cell length of ACMs significantly increased during the first three postnatal months and further increased over the following 9 months. In contrast, the population of ACMs was significantly decreased within the first 5 weeks and reached a plateau in the adult stage. ACMs obtained from newborn and adult mice exhibited similar spontaneous action potentials. The expression of the fetal cardiac gene products atrial natriuretic peptide and voltage-gated T-type Ca(2+) channel Ca(V)3.2 was confirmed by immunostaining in ACMs obtained from both newborn and aged mice. These observations provide evidence that ACMs that exhibit spontaneous beating survive the long-term postnatal development of cardiac ventricles while preserving the expression of fetal cardiac genes. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials.
本研究旨在研究从新生（出生后 1 天（第 1 天））至老年（12 个月大）小鼠心脏中制备的非典型形状心肌细胞（ACMs）的出生后发育变化。ACMs 被鉴定为一种新型的具有独特形态的自搏动心肌细胞，存在于小鼠心室中。ACMs 的细胞长度在前三个月内显著增加，并在随后的 9 个月内进一步增加。相比之下，ACMs 的数量在前 5 周内显著减少，并在成年期达到稳定。从新生和成年小鼠获得的 ACMs 表现出相似的自发动作电位。通过免疫染色，在从新生和老年小鼠获得的 ACMs 中证实了胎儿心脏基因产物心钠肽和电压门控 T 型 Ca(2+)通道 Ca(V)3.2 的表达。这些观察结果提供了证据，表明表现出自发搏动的 ACMs 在心室的长期出生后发育过程中存活下来，同时保留了胎儿心脏基因的表达。本文包含在线补充材料，可在 http://www.jhc.org 访问。请在线访问本文以查看这些材料。
