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Objective To investigate the effects of subthreshold micropulse yellow laser (577 nm) on vascular endothelial growth factor (VEGF),nerve growth factor (NGF) and Chemerin expressions in retina of early stage diabetic rats.Methods A total of 40 Brown Norway rats were treated with streptozocin (65 mg · kg-1) to establish the diabetic model.20 diabetic BN rats' right eyes were received subthreshold micropulse yellow laser (577 run) therapy after 2 weeks.The left eyes were used as control group.At 3 days,7 days,14 days,28 days after laser therapy,5 BN rats were randomly chosen to perform RT-PCR and Weston-blot.The expressions of mRNA and protein of VEGF,NGF and Chemerin were analyzed.Results The expression of VEGF mRNA and protein increased in control group at 3 days,7 days,14 days and 28 days (all P ＜ 0.05).Compared with the control group,VEGF mRNA and protein decreased in the subthreshold micropulse yellow laser (577 nm) group (all P ＜ 0.05).The expression of NGF mRNA and protein decreased in the control group at 3 days,7 days,14 days and 28 days (all P ＜ 0.05),however,the difference was not statistically significant between 3 days and 7 days(P ＞0.05).Compared with control group,NGF mRNA and protein increased in the subthreshold micropulse yellow laser (577 nm) group (all P ＜ 0.05),with maximum expression at 14 days.The expression of chemerin mRNA and protein increased at 3 days,7 days,14 days and 28 days in the control group (all P ＜0.05).Compared with the control group,chemerin mRNA and protein decreased in the subthreshold micropulse yellow laser (577 urn) group (all P ＜ 0.05).Conclusion Subthreshold micropulse yellow laser (577 urn) can suppress VEGF,Chemerin expression and upregulate NGF expression in early stage diabetic rats.
ABSTRACT
Background Intraorbital implantation of coralline porous hydroxyapatite (CHA) is a favorable cosmetic method after enucleation.However,the low degree of vascularizatiou in implant results in implant infection and exposure.Studies showed that a collagen composite sponge treated by basic fibroblast growth factor (bFGF/ collagen composite sponge) can promote angiogenesis.However,whether bFGF/collagen composite sponge improves the vascularization of CHA implants is unclear.Objective This study was to investigate the accelerating effect of bFGF collagen composite sponge on vascularization of orbital implant made of CHA using 99Tcm-methylene diphosphate (MDP) scan.Methods Forty-five New Zealand rabbits were randomly assigned to 3 groups.Evisceration of eyeball was performed on the left eyes of rabbits,and naked CHA,collagen composite sponge wrapped CHA and bFGF/collagen composite sponge wrapped CHA were implanted into the orbit respectively in 3 groups.99Tcm-MDP of 3 mCi was injected in the rabbits via ear vein in 2,4,6,8 and 12 weeks,and the vascular enhancement intensity on implants was observed 3 hours after injection.The ratio of average radioactive count from the area of interest with the same size between the left eyes and the right eyes was calculated.The implants were extracted for histopathological examination in the 12 weeks.Results As the lapse of postoperative time,the inflammation response gradually disappeared and no exposure of implants was seen during the 12-week duration.A similar vascular development strength was found in the area of interest among the 3 groups 2 weeks after surgery.However,the vascular development was significantly enhanced in the left eyes compared the right eyes from 4 to 6 weeks,with the highest intensity in the 8th week in the naked CHA group and collagen composite sponge wrapped CHA group.In the bFGF/ collagen composite sponge wrapped CHA group,the strongest image was in the 6th week after operation.The ratios of average radioactive count between the left eyes and the right eyes were significantly higher in the bFGF/collagen somposite sponge wrapped CHA group compared with the naked CHA group and collagen composite sponge wrapped CHA group (all at P＜0.05),and ratios of average radioactive count of the collagen composite sponge wrapped CHA group was significantly higher than that of the naked CHA group (all at P＜0.05).New blood vessels ingrowed toward the center of the implants through the coralline porous under the optical microscope.Conclusions Both bFGF (20 μg)/collagen composite sponge and collagen composite sponge can accelerate the ingrowth of vessel in the CHA,but the promoting effect of bFGF collagen composite sponge is prominent.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the effect of basic fibroblast growth factor (bFGF) treated collagen composite sponge on vascularization of HA orbital implants.</p><p><b>METHODS</b>New Zealand rabbits received three different orbital implants:naked implants, implants wrapped with collagen composite sponge and implants wrapped with bFGF treated collagen composite sponge.Implants were harvested 2, 4, 6, 8 and 12 weeks after surgery. The vascularization of implants was then assessed by light and electron microscopy.</p><p><b>RESULTS</b>At post-surgery weeks of 2, 4 and 6, bFGF treated collagen composite sponge induced the highest degree of vascularization of orbital implants. Collagen composite sponge alone resulted in higher extent of vascularization than naked implants. Complete vascularization of implants was observed at post-surgery 6 weeks by bFGF treated collagen composite sponge, which was not observed in the other two groups until post-surgery 8 weeks. There were significant differences in the average length of fibrovasculature and in the degree of vascularization among each group at post-surgery 2, 4 and 6 weeks (P<0.05), while no statistical difference was observed at post-surgery 8 and 12 weeks (P>0.05).</p><p><b>CONCLUSIONS</b>bFGF treated collagen composite sponge facilitates fibrovascularization of orbital implants, and shortens the time required for complete vascularization. Collagen composite sponge alone promotes early-stage fibrovascularization, but fails to facilitate complete vascularization of orbital implants.</p>