The Application Of Neurotrophins(CNTF And BDNF) In Treatment Of Rats With Optic Nerve Leison

PURPOSE:To investigate in vivo the survival of retinal ganglion cells (RGCs) after optic nerve was crushed with vitreous cavity injection of neurotrophins(BDNF and CNTF).METHODS: 60 Sprague-Dawly(SD)healthy female rats were randomly divided into 4 groups: control group, BDNF group, CNTF group and neurotrophins(BDNF and CNTF)group. Each group is also divided three time groups: 7-day,14-day, 21-day, every of which contains 5 rats with right eye to be tested and left eye to be normal contrasted. RGCs of adult rats were labeled with fluorogold. Seven days later, the optic nerve was intraorbitally crushed and each group was injected different medicine to vitreous cavity in such order: NaCl(0.9%),CNTF,BDNF,and neurotrophins(CNTF and BDNF). According to different time points, the optic nerve crush rats were perfused. (1)During observation in fluoro-microscope, we randomly select four fields at a distance of 1mm from optic papilla. Then count the amount of FG-labeled survival RGCs in every field and calculate average number and remainder RGCs according to different medicine injected in vitreous cavity and different time. (2) we extract the whole optic nerve, dispose with electron microscope's method and use a computerized image analysis system from which we research varying rule of number of optic nerve fibers of normal rats and those with optic nerve lesion.RESULT:After optic nerve was crushed, each group's densities of RGCs decrease with time lapse. The numbers of RGCs in the three treatment groups, BDNF group, CNTF group and neurotrophins(BDNF and CNTF)group, are obvious more than that of control group at the points of 7-day,14-day and 21-day(P<0.001). The number of RGCs in neurotrophins(BDNF and CNTF)group is also more than those of BDNF group and CNTF group which only use one kind of neurotrophic factors (P<0.001).The result of anxon number of crushed optic nerve testifies that the number live anxon of all treatment group is more than that of control group(P<0.001)and the number of RGCs in neurotrophins(BDNF and CNTF)group is also more than those of BDNF group and CNTF group which only use one kind of neurotrophic factors (P<0.001). The two results, counting anxon number and RGCs number, are coherent.CONCLUTION:In the treatment of rats with optic nerve lesion, using neurotrophins(BDNF and CNTF) is superior than using one neurotrophic factors(CNTF or BDNF)alone.