Objective To investigate the current situation and developing trend of antithrombotic function study of endothelium in vasculartissue engineering. Methods The effect of several elements onthe antithrombotic ability of endothelium, including the source of endothelium,the characteristic of the matrix materials, the cell culture methods, and the endothelium’s gene modification were analyzed. Results The normal antithrombotic function of tissue engineered vascular relied on the source ofendothelium, gene modification of seeding cells, the cell culture methods in vitro, and the characteristic of the scaffolds. Conclusion The establishment of an ideal antithrombotic functional tissue engineering vascular still requires further studies in various aspects including seeding cells, matrix materials, and cell culture methods. Gene modification of vascular endothelium, which improves the antithrombotic ability, deserves more attention.
OBJECTIVE: To explore the mechanism of microvascular spasm after limb ischemia-reperfusion. METHODS: The rabbit hindlimb normothermic tourniquet ischemia model was employed. The tendon on the dorsum of the foot was exposed for observation of microvessels. The responses of arterioles on tendon surface to topical application of 10(-6) mol/L noradrenaline (NE) (a vasoconstrictor), 10(-6) mol/l acetylcholine(Ach) (an endothelium-dependent vasodilator) and 10(-4) mol/L nitroglycerin(NTG) (an endothelium-independent vasodilator) were observed at the period of ischemia and following 30 minutes of reperfusion after 2 hours and 5 hours of ischemia by use of intravital microscopy. RESULTS: No significant changes in the responses of arterioles to NE, Ach and NTG were noted following 30 minutes of reperfusion after 2 hours of ischemia compared with pre-ischemia. The constrictor responses of arterioles to NE were still not significantly altered following 30 minutes of reperfusion after 5 hours of ischemia, however, the dilation responses to Ach and NTG were significantly decreased (to Ach P lt; 0.01; to NTG, P lt; 0.05). CONCLUSION: Reperfusion after 5 hours of ischemia significantly impairs both the endothelium-dependent and endothelium-independent vasodilation, meanwhile preserves constrictor responses to NE, these may contribute to the genesis of the vasospasm in ischemia reperfusion.
Objective To determine the effect of thiazolidinediones (TZDs) on early retinopathy in rats with experimental diabetes. Methods In 40 rats, diabetic models were set up in 36 by one-off intraperitoneal injection with streptozotocin (STZ), and other 4 were in the normal control group. Twenty-four diabetic rats with the disease-duration of more than 6 months underwent intravitreous injection (with rosiglitazone or pioglitazone in 10 rats, respectively), and the rest 4 rats werenprime;t injected with drugs as the diabetic positive control group. Immunohistochemical treptomycin-avidin-biotin-complex (SABC) method, in situ hybridization of retinal vascular endothelial growth factor (VEGF) mRNA, and TdT-dUTP terminal nick-end labelling (TUNEL) were performed on the ocular paraffin section to detect the cellular apoptosis. The difference of VEGF expression and cellular apoptosis between TZDs and control group was observed and analyzed. Results The results of immunohistochemical staining and hybridization in situ were negative in the normal control group. The positive expression rate of VEGF was lower in rosiglitazone and pioglitazone group than which in the diabetic positive control group, and there was no obvious differences of positive expression of VEGF mRNA and cellular apoptosis between the 2 groups. Conclusion TZDs (rosiglitazone and pioglitazone) may inhibit the positive expression of VEGF protein in retina of STZ-induced diabetic rats to some extent, but not affect the growth of VEGF in retina. (Chin J Ocul Fundus Dis, 2006, 22: 7-10)
Obiective lt;brgt;To investigate the change of the activity of proliferation in cultivated Muuml;ller cells treated by advanced glycation endoproducts (AGEs), and the effect of these changes on expression of occludin in bovine retinal vascular endothelial cells (BREC). lt;brgt;Methods lt;brgt;The cultivated Muuml;ller cells were devided into normal growth group and cultured with AGEs group. The cultured BREC were devided into 4 groups:group 1, without any medium; group 2, with normal growth Muuml;ller cell medium (MCM); group 3,MCM treated by AGEs; group 4, without cell as the control. Enzyme-linked immuno sorbent assay was used to detect the content of occludin in the medium in the 4 groups. lt;brgt;Results lt;brgt;The content of expression of occludin was the most in group 2, less in group 1, and the least in group 3. lt;brgt;Conclusion lt;brgt;AGEs may promote the abnormal proliferation of Muuml;ller cells and inhibit the expression of occludin in BREC. lt;brgt;(Chin J Ocul Fundus Dis, 2006, 22: 28-30)
Objective To investigate the effect of batroxobin on the blood-retinal barrier (BRB) and vascular endothelial growth factors (VEGF) in diabetic rats. Methods Sixty Sprague-Dawley rats were used to establish diabetic models by intraperitoneal injecting with streptozotocin (60 mg/kg), and were divided into 3 groups: diabetic group (n=20), batroxobin (40 mg/kg) group (n=20) and batroxobin (20 mg/kg) group (n=20). Twenty-five else rats were in control group. All of the rats were executed 7 days later. The function of BRB was observed by Evans blue method. Results concentration of VEGF protein was detected by enzyme-linked immunoabsorbert assay (ELISA). The results of each group were compared. Results The content of BRB leaked into retina was obvious lower in the control group than which in the other 3 diabetic groups（Plt;0.01）. There was no significant difference of the content of Evans blue between the two groups with different dosage of batroxobin (P＞0.05). The content of Evans blue was lower in the 2 diabetic groups with different dosage of batroxobin than which in the control group (Plt;0.05). The content of VEGF in retina was obviously lower in control group and 2 diabetic groups with different dosage of batroxobin than which in the diabetic group (Plt;0.01), and obviously lower in batroxobin (40 mg/kg) diabetic group than which in the control group (P＝0.01). The content of VEGF in control group and batroxobin (20 mg/kg) diabetic group (P＝0.06) didnprime;t differ much, which occurred similarly in batroxobin diabetic groups with different dosage (P＝0.78). Conclusions Batroxobin may alleviate the damage of function of BRB in diabetic rats and reduce the expression of VEGF, which suggests that batroxobin can protect the function of BRB to a certain extent. (Chin J Ocul Fundus Dis, 2006, 22: 16-19)
Objective To observe the expression of vascular endothelial growth factor (VEGF) in aqueous humor and vitreous body in eyes with proliferative vitreo-retinal diseases, and to investigate the role of VEGF plays in the pathoge nesis of proliferative vitreo-retinal diseases. Methods The concentration of VEGF in aqueous humor and vitreous body in eyes with proliferative vitreoretinopathy (PVR), retinal vein occlusion (RVO), proliferative diabetic retinopathy (PDR), and neovascular glaucoma (NVG) were measured by double antibodies sandwich enzyme-linked immunosorbent assay (ELISA). Results The concentration of VEGF in aqueous humor and vitreous body in eyes with PVR, RVO, PDR and NVG were obviously higher than that in the control group (Plt;0.05), respectively. Among all of the diseases, the concentration of VEGF in aqueous humor and vitreous body decreased orderly in NVG, PDR, RVO and PVR (Plt;0.05). The concentration of VEGF in vitreous body in eyes with PVR, RVO, PDR and in the control group were much higher than that in aqueous humor in corresponding groups (Plt;0.05). There was a negative correlation between the disease history and content of VEGF in aqueous humor and vitreous body in patients with PVR (r=－0.819, －0.823；Plt;0.05). The disease history positi vely correlated with the concentration of VEGF in aqueous humor and vitreous body in patients with RVO (r=0.913, 0.929；Plt;0.05), and the time of vitreous hemorrhage positively correlated with the concentration of VEGF in aqueous humor and vitreous body in patients with PDR (r=0.905, 0.920；Plt;0.05). Conclusion The concentration of VEGF in aqueous humor and vitreous body in patients with proliferative vitreo-retinal diseases significantly increases, and VEGF may play an important role in the pathoge nesis of proliferative vitreo-retinal diseases. (Chin J Ocul Fundus Dis, 2006, 22: 313-316)
Objective To cultivate human retinal capillary endothelial cells (HRECs) and establish two-dimensional model of human retinal vessels in vitro. Methods In a fibronectincoated raising pound, HRECs were cultured by non-serum human-endothelial-cells substrate and two-dimensional model of human retinal vessels was established. Horseradish peroxidase was used to detect the permeability. Some of the vascular models were cultivated with 5 ng/ml vascular endothelial growth factor (VEGF), whose changes of permeability was compared with which of the models without cultivation with VEGF. The effect of VEGF on vascular permeability was observed. Results Meshy vascular structure came into being due to the confluent HRECs after 2 to 4 days. Comparatively complete two-dimensional vascular model after about 6 days. VEGF increased vascular permeability and promoted the formation of blood vessels. Conclusion HRECs can be cultivated successfully with human-endothelial-cells substrate; standard retinal two-dimensional vascular model in vitro can be established by using cellular raising pound and non-serum human-endothelial-cells substrate. (Chin J Ocul Fundus Dis, 2006, 22: 110-112)
Objective To detect the apoptosis of vascular endothelial cells and retinal pigment epithelial (RPE) cells in vitro induced by verteporfin-photodynamic therapy. Methods Cultured vascular endothelial cells and human RPE cells were incubated with verteporfin at a concentration of 1.0 mu;g/ml which was equivalent to the initial plasma level of verteporfin in clinical therapy. Each kind of cells were divided into 6 groups according to different time of incubation: 0, 5, 15, 30, 60, and 120 minutes group. After incubated, the cells were illuminated by the laser light with the maximum wavelength of absorption of verteporfin (wavelength: 689 nm, power density: 600 mW/cm2) with the power of 2.4 J/cm 2for 83 seconds. The percentage of cellular apoptosis was measured by flow cytometry 3 hours after PDT, and the measurement was repeated thrice. Results The proportion of cellular apoptosis 3 hours after PDT were 0.01plusmn;0.01, 0.25plusmn;0.02, 0.32plusmn;0.02, 0.41plusmn;0.04, 0.49plusmn;0.03 and 0.61plusmn;0.02, respectively in 0-120 minutes group of vascular endothelial cells; and 0.02plusmn;0.01, 0.22plusmn;0.01, 0.31plusmn;0.02, 0.38plusmn;0.03, 0.47plusmn;0.05 and 0.58plusmn;0.03 respectively in 0-120 minutes group of RPE cells. The proportion of cellular apoptosis of both kinds of the cells increased as the incubation time was prolonged. There was no significant difference of the percentage of cellular apoptosis between the accordant time groups in the two kinds of cells (P＞0.05). Conclusions Cellular apoptosis can be quickly induced by verteporfin-PDT both in human vascular endothelial cells and RPE cells; under the same condition in vitro, PDT has no obvious selection for the apoptosis of the two kinds of cells. (Chin J Ocul Fundus Dis, 2006, 22: 253-255)
Objective To investigate the impact of photodynamic therapy (PDT) with verteporfin on the expression of pigment epithelial derivative factor (PEDF) mRNA and vascular endothelial growth factor (VEGF) mRNA in adult retinal pigment epithelial (RPE) cells in vitro. Methods The changes of cellular viability before and after PDT were assessed by methyl thiazolyl tetrazolum (MTT) colorimetric assay. Semiquantitative reverse transcription-polymerase chain reaction (RT-PCR) was conducted to detect the expression of PEDF and VEGF mRNA in RPE cells before and after PDT. Results PDT caused the death of RPE cells. The cellular mortality was positively correlated with the power of photocoagulation and the concentration of verteporfin. Conclusion PDT could downregulate the expression of PEDF and VEGF mRNA in adult RPE cells in vitro, which may relate to the cure or relapse of subfoveal choroidal neovascular membrane after PDT. (Chin J Ocul Fundus Dis, 2006, 22: 256-260)