| Retinal detachment (RD) is a common cause of human visual impairment. With the development of basic research and operational technique, detachmental retina is almost recovered its anatomic position. However, visual function is not well. Outer-segment degeneration, photoreceptor apoptosis and their imperfect regeneration were considered the most likely cause of continued visual deficits after successful reattachment. Nerve growth factor (NGF) not only promote neurotrophy and synaptogenesis, but also control the growth, development, differentiation, regeneration and functional expression of neuron. In pathological conditions, NGF also prevents the neuron's apoptosis and enhances its survival ability in the pathological environment.Objective: To study whether NGF have the ability to protectphotoreceptor or not in this experiment, RD models were made in right eye of each rabbit and divided into NGF treated group, NS model group. The dynamic changes of the retinal structure and function were observed systematically, which provide a theoretical and experimental evidence for clinic treatment.Methods: The study was divided into three steps to perform. We choose healthy adult bluish purple-colored rabbits of 2.5-3.5kg. A. Biochemical test group: 54 rabbits were divided into 3 groups: normal control group, NGF treated group and NS model group. Each group had 18 rabbits, which divided into three sub-groups: 3-,7- and 14-day group. Each sub-group had 6 rabbits. An experimental model of RD was induced in right eye of each rabbit in NGF treated and NS model group. O.lml NGF(lmg/ml) was injected under conjunctiva twice a day in NGF treated group and NS O.lml in NS model group. In order to evaluate the level changes of biochemical signs after NGF administrated, the rabbits were sacrificed at 3 , 7 and 14 days after RD. The levels of glutamate (GLU) in vitreous were measured by high performance liquid chromatography (HPLC) and the retinal levels of nitric oxide (NO) and malonyldialolehyde (MDA) were also measured. B. light and electron microscope group: 26 rabbits were divided into 3 groups at random: normal control group, NGF treated group and NS model group. Both NGF treated group and NS model grouphave 6 rabbits and the other group has 2 rabbits respectively. The experimental method was above mentioned. The rabbits were sacrificed at 3 ,7 and 14 days after RD. The morphologic changes of retina were observed by light and electron microscope. The terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNED technique was applied to assess the photoreceptor apoptosis in 3-day group. C. 14-day light microscope group: 18 rabbits were divided into 3 groups at random: normal control group, NGF treated group and NS model group. Each group had 6 rabbits. The experimental method was above mentioned. The rabbits were sacrificed at 14 days after RD. The thickness and the number of photoreceptor were measured by light microscope, which was taken as the injure sign of retinal structure after administration.Results : (1) Biochemical test group Excitatory amino acid-GLU : The GLU level of vitreous in the 3-,7-day, NGF treated group (9.35 ± 1.17; 19.39 ± 4.88) umol/L was less than those in the 3-,7-day, NS model group (15.18±1.87; 29.04± 4.25 ) umol/L, which has an obvious difference respectively between two groups (P <0.01; P <0.05 ) . There was no significant difference of GLU level in vitreous between the 14-day, NGF treated group (14.58 ± 2.65) umol/L and the 14-day, NS model group (15.44 ± 3.91) umol/L. Retinal NO level Retinal NOlevel in the 3-day, NGF treated group (23.90 ± 7.64) mol/gpr was less than those in the 3- day, NS model group (45.19±11.61) jimol/gpr, which had a significant difference (P<0.05). Retinal MDA level There had no obvious difference of retinal MDA level among the 3-,7- and 14- day NGF treated group (159.71 ± 23.09; 216.72±12.15; 151.71±29.38) nmol/mgpr and the NS model group (165.58 ± 26.19; 219.46±15.44; 154.57 ± 23.39) nmol/mgpr (P>0.05). (2) Light and...
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