Dynamic observation of morphologic change of sinoatrial node cells of rabbits after acute damages / 第三军医大学学报

ABSTRACT

Objective To explore the regularity of dynamic morphologic changes of the sinoatrial node (SAN) cells of rabbits after the constitution was damaged by formaldehyde wet dressing. Methods Sixty rabbits were randomly divided into 6 groups (n=10 in each group) the control group and 5 experimental groups observed at 2 h, 1, 2, 3, and 4 weeks respectively after the operation. The SAN constitution of rabbits was damaged by 20% formaldehyde wet dressing. The constitutions of SAN were cut quickly at 2 h after wet dressing in the control group and at the corresponding time points in other experimental groups respectively. The specimens were made for light microscopical and electron microscopical observations. The apoptosis of SAN cells was detected by TUNEL method. Results Compared with those in the control group, SAN cells in all experimental groups were damaged at various degrees observed by light microscopy and electron microscopy. Distinct cell tumefaction, soak of grain cells, cytoclasis, hyperplasia of collagen fibers, and other pathological changes were detected. Electron microscopical observation showed distinct pathological changes of the super-micro construction of cells. Apoptosis was not detected in the control group, but various degrees of apoptosis in all experiment groups. The apoptotic rates in all experimental groups were significant as compared with that in the control group (P