Objective To investigate the effect of inducible nitric oxide synth ase (iNOS) or cyclooxygenase－2 (COX－2) on retinal neovascularization and its possible mechanism in oxygen－induced retinopathy （OIR） mouse model. Methods Retinal neovascularization was induced by oxygen with different concentration. The expression of iNOS, COX－2, matrix metalloproteinases 2 (MMP－2) and vascular end othelial growth factor (VEGF) in the retinae of experimental animals were analyzed by immunohistochemistry, realtime polymerase chain reaction and western blotting technologies. Results The inhibition of COX－2 or iNOS obviously attenuated retinal neovascularization and decreased the expression of VEGF and MMP－2. The iNOS inhibition decreased COX－2 expression, and vice versa. Conclusions COX－2 and iNOS may play a role in retinal neovascularization in OIR mouse model, which may act by regulating the expression of VEGF and MMP－2.
【Abstract】Objective To investigate the expression of inducible nitric oxide synthase (iNOS) and p53 protein in hepatocellular carcinoma (HCC) and their relationship with angiogenesis. Methods Immunohistochemical method and image analysis technique were used to detect the expression of iNOS and p53 protein in tumor tissue sections of 59 HCC patients. Microvessel density (MVD) was counted by immunohistochemical staining with anti-CD34 antibody.Results ①The expression rates of iNOS and p53 were 81.4%(48/59), 64.4%(38/59) in HCC patients, respectively. The expression intensities of iNOS and p53 were 5 635±1 287, 3 352±873 in HCC patients, respectively. ②MVD was 32.5±2.73 in the tumor tissue of HCC patients. ③The expression of iNOS was correlated with the expression of p53 and MVD in HCC patients (P＜0.05); The expression of p53 was also correlated with the MVD in HCC patients (P＜0.05). Conclusion iNOS and p53 are highly expressed in HCC and may play a key role in angiogenesis of HCC.
Objective To observe the expression of matrix metalloproteinase-9 (MMP-9), its tissue inhibitor of matrix metalloproteinase (TIMP-1), inducible nitric oxide synthase (iNOS) and contents of nitric oxide (NO) in the ocular tissues of Sprague-Dawley (SD) rats with endotoxin induced uveitis（EIU）. Methods Ninety SD rats were randomly divided into experimental (81 rats) and control group (9 rats). The model of EIU was induced in rats in experimental group by injecting with lipoplysaccharide (LPS) 200 μl into the hind feet pads, while the rats in the control group were not injected. Nine rats were executed 0, 6, 12, 18, 24, 48, 72, 96 hours and 7 days, respectively, after injecting with LPS; the NO content and concentration of protein in the aqueous humor in blood plasma, aqueous humor, and uveal tissues were detected. The expressions of MMP-9, TIMP-1 and iNOS in the ocular tissues were detected by immunohistochemistry, and the average absorbance (A) value was evaluated by computer medical image analysis system. Results iNOS, MMP-9 and TIMP-1 expressed in the epithelial cells of iris and ciliary body and exudated inflammatory cells of rats. The concentration of protein in the aqueous humor, the contents of NO in blood plasma, aqueous humor, and uveal tissues, and A value of MMP-9 had obvious relativity with the inflammatory extent, while no positive correlation was found between the inflammatory extent and the A value of iNOS and TIMP-1. Expression of iNOS was found 6 hours after injection, reached the peak after 12 hours, and then dropped gradually. The expression of TIMP-1 could be seen 24 hours after injection, and reached its peak after 72 hours. Conclusion The content of NO and expressions of iNOS, MMP-9 and TIMP-1 changes from the beginning and during the development of EIU, which suggests that NO, iNOS, MMP-9 and TIMP-1 are involved in the pathologic process of EIU. (Chin J Ocul Fundus Dis, 2005, 21: 371-374)
OBJECTIVE To study the protective effects of Schwann cell derived neurotrophic factor (SDNF) on motoneurons of spinal anterior horn from spinal root avulsion induced cell death. METHODS Twenty SD rats were made the animal model of C6.7 spinal root avulsion induced motoneuron degeneration, and SDNF was applied at the lesion site of spinal cord once a week. After three weeks, the C6.7 spinal region was dissected out for motoneuron count, morphological analysis and nitric oxide synthase (NOS) enzyme histochemistry. RESULTS 68.6% motoneurons of spinal anterior horn death were occurred after 3 weeks following surgery, the size of survivors was significantly atrophy and NOS positive neurons increased. However, in animals which received SDNF treatment, the death of motoneurons was significantly decreased, the atrophy of surviving motoneurons was prevented, and expression of NOS was inhibited. CONCLUSION SDNF can prevent the death of motoneurons following spinal root avulsion. Nitric oxide may play a role in these injury induced motoneuron death.
【Abstract】ObjectiveTo investigate the protective effect of melatonin on renal injury induced by bile duct ligation in rats. MethodsSixtyfour rats were randomly divided into four experimental groups (n=16 rats per group): the control group (CN), sham operative group (SO), bile duct ligation group (BDL) and bile duct ligation melatonin treatment group (BDL+Mel). Obstructive jaundice was induced by common bile duct ligation. Plasma level of nitric oxide (NO), total bilirubin (TB), direct bilirubin (DB), alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea nitrogen (BUN) and creatinine (Cr) were measured 4 d and 8 d after operation. NO and inducible nitric oxide synthase (iNOS) in renal tissue were detected at the same time point, too. Histopathological changes of kidneys were examined by HE staining. ResultsIn BDL group, the plasma levels of NO, TB, DB, ALT, AST, BUN and Cr were higher than those of SO group (P＜0.01）, and the level of NO and activities of iNOS in renal tissue were significantly increased (P＜0.01）. However, in BDL+Mel group, the plasma levels of NO, ALT, AST, BUN and Cr were lower than those of the BDL group (P＜0.01）, and the level of NO and activities of iNOS in renal tissue were significantly suppressed (P＜0.01）; histopathological changes of kidneys were improved.ConclusionAugmentation of iNOS activities and increasing of NO production in local tissue contributed to renal injury induced by bile duct ligation, and the mode of melatonin’s protective actions, at least in part, relates to interference with no pathways.
ObjectiveTo detect the induction of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) production in immunostimulated retinal pigment epithelial (RPE) cells to seek for the supplying of the arginine, a substrate for NOS; as well as the effects of produced NO on the tight junction of RPE-J cells. MethodsRat′s RPE-J cells were treated with interferon-γ(INF-γ), tumor necrosis factor-α(TNF-α) and lipopolysaccharide (LPS), and Northern and Western blotting were applied to analyze the expression of the citrulline-NO cycle enzymes and related enzymes and the effect of dexamethasone and cyclic adenosine monophosphate (camp) on the expression of iNOS. Immunocytochemistry reaction and Western blotting were used to evaluate the effect of produced NO on the tight junctions of RPE-J cells.ResultsiNOS and argininosuccinate synthetase (AS) were highly induced at both mRNA and protection levels in immunostimulated RPE cells while arginiosuccinate lyase (AL) was not induced. NO was produced by cells after stimulation with TNFα, IFNγ and LPS. The induction of iNOS mRNA and the production of NO by these immunostimulated cells was further enhanced by cAMP. NO was produced from citrulline as well as from arginine. And the produced NO impaired the tight junction of RPE-J cells, decreased the production of tight junction related protein ZO-1.ConclusionIn activated RPE-J cells, citrullinearginine recycling is important for NO production, and the produced NO weakened the function of tight junction of RPE-J cells.(Chin J Ocul Fundus Dis, 2005,21:32-36)
Objective To analyse the changes of nitric oxide and nitric oxide synthase in rat retina under acute high ocular pressure and study the effect of nitric oxide in rat retinal damage under hypertension. Methods Sixty Wistar rats were divided randomly into five groups:Ocular hypertension 30 min,60 min,90 min and 12 h,24 h after reperfusion．Elevation of the ocular pressure in the anterior chamber of the rat eye ca used retina ischemic damage．The changes of retinal nitric oxide content were ob served indirectly by measuring NO2－/NO3－ content in retina.The distribution and changes of neuronal constitutive nitric oxide synthase (ncNOS)were studied by immunocytochemical localization of ncNOS. Results ncNOS positive neurons were distributed in the inner nuclear layer (INL),ganglion cell layer (GCL) and the inner plexiform layer of the normal and ischemic rat retina.During acute high IOP 30 min,60 min and 90 min,NO content decreased gradually and ncNOS immune activity weakens.During reperfusion,NO content increased remarkably (Plt;0.05) as compared with the groups of hypertension 90 min and decreased remarkably as compared with the normal rat retina.But ncNOS positive neurons continue to decrease compared with the groups of hypertension 90 min. Conclusion NO participates the rat retinal injury by acute elevated intraocular pressure, and nitric oxide synthetized by ncNOS may play an important role in protecting the retina from ischemic and post-ischemic injury.
Objective To investigate the long effect of nonpulsatile flow on changes of structure and function in pulmonary microcirculation and to identify the pulmonary reconstruction under this blood perfusion. Methods Canine models with nonpulsatile flow in the right lung was established, and sacrificed 6 months later. Compare endothelial nitric oxide synthase (eNOS) in vascular endothelium, apoptosis in smooth muscle cell with immunohistochemistry by streptavidinbioepidermmultienzyme complex methodes, and observe structural changes in pulmonary arterioles with optical microscope. Results The expression of eNOS in the right nonpulsatile flow perfusing lung was weaker as compared to the left lung （10 846.7±177.8 vs. 13 136.1±189.6;t＝2.240, P=0.040）, the fas was ber as compared to the left lung（14 254.1±217.1 vs. 11 976.7±195.7; t＝2.160, P=0.040）. The ratio of wall thichness/vessel diameter in the right lung（13.64%±12.80% vs. 14.96%±13.10%） and wall area/vessel area(46.40%±11.70% vs. 47.80%±12.20%) was lower as compared to the left lung(Plt;0.05). Conclusion Longterm nonpulsatile flow can decrease the expression of eNOS, contract the muscles in capillary net, and increase pulmonary vascular resistance. Moreover it canincrease the arteriole apoptosis, leading to vascular structure remodeling.