RESUMEN
Objective:To investigate the expression of AQP4 during the development of presyrinx state of experimental syringomyelia in rabbits.Methods:The experimental syringomyelia models of rabbits were established by intra-cisternal injection of Kaolin.The expression of AQP4,AQP4mRNA and the water content of upper cervical spinal cord were measured with immunohistochemistry,Western blot,RT-PCR and dry-wet measurement on days 1,3,7,14,and 21 after operation,respectively.Results:Compared with animals of control group,the water content increased in those of Kaolin group from the 1st day(68.35%?0.70%),reached its peak on the 7th day(72.92%?0.86%),lasted to the 14th day(72.58%?0.55%),and then began to drop on the 21st day(70.03%?0.77%),while AQP-4 immunoreactive expression decreased on the 3st day[integral optical density(IOD)320.5?44.2],reached its minimum on the 7th day(IOD 258.7?26.5),lasted to the 14th day,and recovered partially on the 21th day approximately(IOD 321.5?46.1).RT-PCR found the decreasing of AQP4 mRNA coincided well with that of AQP4 immunoreactive expression in presyrinx state.The linear regression analysis indicated that expression of AQP4 and its mRNA in cervical cord had a negtive correlation with the change of spinal water content(r=-0.769,P