Localization,cultivation and purification of sinoatrial nodes isolated from newborn rabbits / 中国组织工程研究

ABSTRACT

BACKGROUND: The method of culture purified sinoatrial node cell is important in investigating its ultrastructural characteristics and autorhythmic mechanisms.However,the corresponding method has not been standardized.OBJECTIVE: To summarize the localization,cultivation and purification of sinoatrial nodes isolated from newborn rabbits,and to study the morphological characters of primary cultured pacemaker cells.METHODS: Hearts of the newborn rabbits(within 24 hours)were embedded in paraffin for hematoxylin-eosin staining,The location of sinoatrial nodes was observed under an optical microscope,the morphology of sinoatrial nodes cells were observed by light microscope and electron microscope.RESULTS AND CONCLUSION: Sinoatrial nodes localized in the anterior wall of the superior vena cava and the posterior laterial wall of right atrium.There was about 0.32 mm between its lowest point and sulcus terminalis.Three distinct types of cells were observed among the cultured cells of sinoatrial nodes spindle,spider and polygon.The spindle cells occupied the greatest proportion of the cultured cells(59.6±7.3)%.The spontaneous contraction frequency of spindle cells was the highest among the constracting cells(145±9)times per minute.The ultrastructure observation showed that myofibrils and other organelles in spindle cells were sparse and significantly decreased in number compared with triangle cells.There was no significant difference between triangle cells isolated from sinoatrial nodes and from atrial muscle.Sinoatrial nodes could be harvested along the anterior root of the superior vena cava down to the posterolateral sulcus.Among the cultured cells from neonatal rabbit sinoatrial nodes,the spindle cells with small body and fast pulse frequency are pacemaker cells.