ObjectiveTo evaluate the protective effect of estrogen on survival of retinal ganglion cells (RGCs) after transient retinal ischemia-reperfusion (RIR) in rats.MethodsRIR was induced in 60 ovariectomized adult rats (OVX) by increasing intraocular pressure via an intracameral catheter. All of the rats were divided into two groups randomly: in experimental group, the rats underwent a subcutaneous injection with 17β-estrodiol（100 μg/kg） 2 hours before retinal ischemia; and in the control group, saline water was injected correspondingly. The number of RGCs and the thickness of the inner retinal layers were mesured by HE staining method before and 12, 24, 48, and 72 hours after reperfusion. TdT-mediated biotin-dUTP nick end labelling (TUNEL) staining technique was used to examine the apoptosis of RGCs.ResultsTwenty-four and 48 hours after reperfusion, the number of apoptotic cells in experimental group was obvious lower than that in the control group(Plt;0.05), and the number of RGCs in experimental group was higher than that in the control group(Plt;0.05).ConclusionEstrogen can protect retinal neurons from transient RIR in ovariectomized rats.(Chin J Ocul Fundus Dis, 2005,21:177-179)
ObjectiveTo observe the effect of Crocin on structure and the expression of tumor necrosis factor-alpha; (TNF-alpha;) and interleukin-1beta; (IL-1beta;) in rat retina after injury by ischemia-reperfusion. Methods A total of 80 Sprague-Dawley male rats at the age of 8 -10 weeks were divided into control group, model group, low-dose Crocin group and high-dose Crocin group, with 20 rats in each group. The rats of control group were not treated. The rats in model, low-dose Crocin and high-dose Crocin group were induced with normal saline by anterior chamber perfusion creating a retinal ischemia-reperfusion (RIR) model. The rats of the low-dose Crocin and highdose Crocin group received intraperitoneal injection with different doses of Crocin solution (5 mg/kg, or 50 mg/kg) 30 minutes prior to ischemic injury and one time per day after successful RIR. Optical microscopy was used to observe the retinal structure. Enzymelinked immunosorbent assay (ELISA) was used to measure the expression of TNF-alpha; and IL-1beta; 6, 12, 24 and 48 hours after RIR. ResultsThe retinal structure of control group was normal. Pathological changes were found in the RIR model and low-dose Crocin group, such as retinal edema, disorganized structure and loosely packed cells. The degree of pathological changes in lowdose Crocin group was less than the RIR model group. The retinal structure of high-dose Crocin group was similar to the control group. The expression of TNF-alpha; was the highest at 24 hours after modeling, while the expression of IL-1beta; was the highest at 12 and 48 hours after RIR modeling. Six, 12, 24 and 48 hours after RIR modeling, compared with the control group, the TNF-alpha; expression of model (t=5.42, 7.94, 9.32, 9.18;P＜0.05 ), low-dose Crocin (t=3.94, 4.12, 4.98, 3.84;P＜0.05) and high-dose Crocin group (t=2.13, 2.34, 2.96, 2.78;P＞0.05) were increased. Compared with the RIR model group, the TNF-alpha; expression of low-dose Crocin (t=3.95, 4.56, 4.01, 5.12) and high-dose Crocin group (t=5.23, 7.65, 7.74, 7.63) was decreased. Compared with the control group, the IL-1beta; expression of model (t=7.23, 7.87, 7.15, 15.60), low-dose Crocin (t=5.65, 5.10, 5.54, 6.87;P＜0.05) and high-dose Crocin group (t=4.38, 5.21, 4.56, 4.75) was increased (P＜0.05). Compared with the model group, the IL-1beta; expression of low.dose Crocin group was decreased significantly 48 hours after RIR modeling (t=7.56,P＜0.05); but it decreased significantly at each time point in high-dose Crocin group (t=6.94, 5.36, 6.05, 10.50;P＜0.05). Conclusion Crocin can improve the retinal pathologic changes, while down-regulating TNF-alpha; and IL-1beta; expression in RIR rats.
Objective To investigate the effects of different reperfusion sequence on hepatic warm ischemia-reperfusion injury and its related mechanisms. Methods Ninety-six healthy male Sprague Dawley rats were randomly divided into 6 groups by using random digits method (n=16, each)： Sham operation group, only shammed operation for negative control; the other 5 groups were all experimental groups, which were divided according to different reperfusion sequences of portal vein and hepatic artery: reperfusion first through the portal vein for 1 min with subsequent full reperfusion group, reperfusion first through the portal vein for 2 min with subsequent full reperfusion group, reperfusion first through the hepatic artery for 1 min with subsequent full reperfusion group, reperfusion first through the hepatic artery for 2 min with subsequent full reperfusion group, simultaneous reperfusion through the portal vein and hepatic artery group. Each group was further randomly divided into two subgroups (n=8, each) for sample collection at 2, 4 hours after reperfusion respectively. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST) and malondialdehyde (MDA), superoxide dismutase (SOD) and glutathion (GSH) in hepatic tissue were detected respectively. HE staining of histopathologic slides was used to observe the morphological changes of hepatic tissue. TUNEL method was used to assess the apoptosis index (AI) of hepatocytes. Results The liver of rat was approximately normal in the sham operation group with lower levels of ALT, AST, MDA and AI, and higher levels of SOD and GSH as compared with all the experimental groups (P＜0.01). Less hepatic ischemia-reperfusion injury was found in reperfusion first through the portal vein for 1 min with subsequent full reperfusion group, whose ALT, AST, MDA and AI levels were significantly lower than those of the other experimental groups (P＜0.05 or P＜0.01), and its SOD and GSH levels were higher than those of the other experimental groups (P＜0.05 or P＜0.01). HE staining also showed milder hepatic injury in reperfusion first through the portal vein for 1 min with subsequent full reperfusion group as compared with the other experimental groups. Conclusion Hepatic reperfusion first through portal vein for short time with subsequent full reperfusion could depress the synthesis of free oxygen radicals and suppress apoptosis of hepatocytes, thus relieving hepatic ischemia-reperfusion injury.
Abstract： Objective To investigating the variance of nuclear factorkappa B（NF-κB）,inflammatory factor and polymorphonuclear cells(PMNs) in lung， our study infer the role of PMNs infiltration and early activity of NF-κB in empirical study of lung injury in deep hypothermia and circulatory arrest. Our study also guess the possible mechanism of action in order to provide a more excellent program for lung protection. Methods Twelve immature pigs were randomly divided into two groups，there are six pigs in each group，one group was normothermic parallel circulation(control group)，the other was deep hypothermia and circulatory arrest(DHCA, experimental group)，we obtain lung tissue and venous blood from pigs to measure the variances of NF-κB by immunohistochemistry and inflammatory factor by enzymelinked immunosorbent assay(ELISA) at different time. Results The expression of NF-κB of the lung tissue specimen was negative before parallel circulation in both groups, there was no brown dyed cell nucleus and the variation was no statistically difference in two groups. The expression of NF-κB reached it‘s peak at half an hour of ischemia reperfusion, and most of the brown dyed cell nucleus were PMNs, then the expression of NF-κB decreased in the experimental group. The lung tissue specimens were all weakly negative at the time points after parallel circulation and there was no statistical difference among them. But the content of inflammatory factor increased gradually from half an hour of ischemia reperfusion to two hour of ischemia reperfusion， which reached their peak at two hour of ischemia reperfusion.There was significance variances at the content of tumor necrosis factor-α(TNF-α) at one hour of ischemia reperfusion， while at one and a half hour of ischemia reperfusion. There was significance variance at the content of interleukin-8 and interleukin-6 in the experimental group. While in the control group, there was statistically difference before and after parallel circulation, but there was no statistically difference among the time points after parallel circulation. Conclusion The early activity of NF-κB may have an important role in lung injury of DHCA，treatments aim directly at NF-κB may provide an important strategy for lung injury of DHCA.
Objective To investigate the expression of nuclear factor (NF)-κB and intercellular adhesion molecule (ICAM)-1 in rat′s retina injured by ischemia-reperfusion, and the effect of pyrrolidine dithiocarbamate (PDTC) on the expression of NF-κB and ICAM-1. Method The model of retinal ischemia-reperfusion was set up in 60 SD rats, which were divided into two groups with 30 rats in each: ischemia-reperfusion group and ischemia-reperfussion with injection of PDTC group. The left cephalic artery of each rat was ligated, and the right side was the control. Every group was subdivided into group 1 hour, 6, 12, 24, 48, and 72 hours after ischemia-reperfusion injury, and with 5 rats in each group. mRNA of NF-κB and ICAM-1 mRNA was measured by in situ hybridization (ISH) method in rat′s retina. Every rat underwent electroretinography (ERG) at the corresponding time before executed by neck breaking. Results In ischemia-reperfusion group, expression of NF-κB and ICAM-1 was detected at the 6th hour after ischemia-reperfusion, reached the highest level at the 24th hour, and weakened gradually later. In ischemia-reperfusion with injection of PDTC group, expression of NF-κB and ICAM-1 was detected at the 12th hour after ischemia-reperfusion, and reached the highest level at the 24th hour but lower than that in ischemia-reperfusion group. No expression of NF-κB and ICAM-1 was found in the control group. The relative recovery rate of ERG a and b wave amplitude in ischemia-reperfusion groups was lower than that in ischemia-reperfusion with injection of PDTC group at every stage(P＜0.01 ). The lowest relative recovery rate of ERG a and b wave amplitude in different stages in both of the 2 groups was at the 24th hour(P＜0.01). Conclusions NF-κB and ICAM-1 may play an important role in retinal ischemia-reperfusion injury, as the inhibitor of NF-κB, PDTC may relieve the retinal ischemia-reperfusion injury. (Chin J Ocul Fundus Dis，2004，20：175-178)
Objective To explore the effect of ischemia-reperfusion injury on the retinal functions of rats. Methods Seventy Wistar rats were selected, 20 of which were selected randomly and divided into two groups (control group and single-irrigated group). The rats were anesthetized and their anterior chambers of the right eyes were cannulated with a 7-gauge needle connected to a reservoir containing ringers balanced salt solution, which was maintained at the same level o f the eye for 1 hour. After that, ERG was recorded in both eyes of all rats. All the left rats were divided randomly into 10 groups and they were treated as the single-irrigated group. Retinal ischemia was induced by raising the reservoir to a height of 150 mm Hg. One hour later except the single ischemia group, all o f t he groups resumed perfusion after 3,6,12,and 24 hours and 3,5,7,14,and 21 days s eparately. ERG was recorded in both eyes of all rats.Results There was no difference in the results of ERG between left and right eyes in either the control group or the single-irrigated group. All the waves of ERG vanished in the single-ischemia group after 1 hour. In the ischemia-reperfusion groups, the waves of ERG partly recovered and the amplitude reduced persistently and progressively.Conclusion Ischemia-reperfusion injury may affect the function of the retina persistently and progressively. (Chin J Ocul Fundus Dis，2003，19：201-268)
Exosomes are nanovesicles actively secreted by cells, which selectively encapsulate biologically active molecules such as proteins, RNA, and cytokines. They play an important role in intercellular communication, immune regulation, and maintenance of homeostasis, which can also be used as carriers for targeted drug delivery. Retinal ischemia-reperfusion injury (RIRI) is a retinopathy that seriously threatens human vision. At present, the clinical treatment of these diseases are symptomatic treatments, and some patients have poor efficacy or even blindness. As extracellular vesicles rich in functional proteins and RNAs, exosomes can not only be used as drugs for the treatment of RIRI, but also be used as carriers for drug delivery to play synergistic therapeutic effects. In the future, with the deepening of the research on the molecular structure, contents and biological functions of exosomes, as well as the continuous development of ophthalmic biology and genetic engineering technology, exosomes are expected to exert their great potential as therapeutic drugs and carriers, and become an important means of treating RIRI.
Objective To study the protective effects of pre-storing glycogen on warm ischemia reperfusion injury during partial hepatectomy. Methods Thirty-eight patients were randomly divided into a trial group (n=19) and a control group (n=19). In the trial group, patients were given high concentration glucose intravenously during the 24 hours before the operation. The hepatic lesion was resected after portal triad clamping in the two groups. Liver function of all patients was measured before the operation and the first and fifth days after the operation. Normal hepatic tissue was biopsied to measured hepatic tissue glycogen contents before the operation and the change of superoxide dismutase (SOD) at the point of pre-ischemia, post-ischemia, and reperfusion 2 hour. Bcl-2 mRNA, a well known anti-apoptotic factor, was also detected using quantitative polymerase chain reaction. Results The hepatic tissue glycogen content of the trial group was significantly higher than that of the control group before the operation (Plt;0.01). Liver function of the trial group was significantly better than that of the control group on the first and fifth day after operation (Plt;0.05). There was significant difference in SOD activity between the two groups at the end of hepatic vascular occlusion and at the point of 2-hour reperfusion (Plt;0.05). Furthermore Bcl-2 mRNA expression of the trial group was notably up-regulated at the point of 2-hour reperfusion compared to the control group. Conclusion Pre-store storing glycogen might protect liver ischemia reperfusion injury caused by hepatic vascular occlusion during partial hepatectomy. The potential mechanism might be that pre-storing glycogen enhances Bcl-2 expression.
Objective To observe the effect of melatonin (MT) on retinal apoptosis in rats with ischemia-reperfusion injury (RIRI). Methods A total of 54 male healthy Sprague-Dawley adult rats were randomly divided into the normal control (CON) group (6 rats), RIRI group (24 rats) and MT group (24 rats). The rats of RIRI and MT group were induced using suture-occluded methods to establish RIRI model. The rats of MT group were injected with MT in the left carotid artery 30 minutes after RIRI, and RIRI group was injected with the same amount of saline. On 6, 24 hours and 3, 7 days after RIRI, the morphological changes of retina were evaluated by hematoxylin and eosin (HE) staining; the effects of MT on retinal cell apoptosis and Nrf2, HO-1 proteins were examined by immunohistochemistry staining. The correlation between active Caspase-3 and Nrf2 protein, active Caspase-3 and HO-1 protein in MT group were analyzed by linear regression analysis. Results HE staining results showed that the morphology of retinal cells was regular and retinal cells were well arranged in the CON and MT group. In the RIRI group, both the thickness of inner retinal layer and the number of retinal ganglion cells (RGC) were decreased. On 6, 24 hours and 3, 7 days after RIRI, the thickness of inner retinal layer (F=16.710, 62.303, 68.389, 57.132; P＜0.01) and RGC number (F=24.250, 11.624, 14.155, 32.442; P＜0.05) in MT group were more than those in RIRI group. Immunohistochemistry staining results showed that less active Caspase-3+ cells were observed in MT group as compared with those in RIRI group at each time points (F=49.118, 134.173, 76.225, 18.385; P＜0.01). There were more Nrf2+ (F=11.041, 31.480, 59.246, 6.740; P＜0.05) and HO-1+ cells (F=128.993, 21.606, 51.349, 8.244; P＜0.05) in MT group as compared with those in RIRI group at each time points. Linear regression analysis results showed that the difference of active Caspase-3+ cells were all linearly correlated with the Nrf2+ cells and HO-1+cells in the MT group (r2=0.810, 0.730; P＜0.01). Conclusion MT could reduce retinal cell apoptosis in RIRI rats, and its mechanism may be associated with increased Nrf2 and HO-1 expression, reduced active Caspase-3 expression.
Objctive To explore the relationship between the expression of Fas/FasL and the apoptosis occurs in retinal ischemia/reperfusion injury of rats , as well as the therapeutic effects of bFGF on the ischemic retina.Methods Th emodels of retinal ischemia/reperfusion injury was made by transient elevating introcular pressure. A total of 28 rats were divided into normal and operation group.The latter were subdivided into 1 hour, 6, 12, 24, 48 and 72 hours after reperfusion group, in which the left eyes of the rats were in the ischemia/reper fusion groups and the right ones were in the treatment groups (bFGF intracameral injection). Apoptosis was assessed by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labelling (TUNEL) method, and the expression of Fas and Fas ligand was studied by strept avidin-biotin complex （SABC）immunohistochemistry. Results No positive cells were observed in the normal rats′retinae, but there was a significant number of TUNEL positive cells in 6-24 hours after transient ischemia followed by a decrease at the 48th hour. The number of TUNEL positive cells reached a maximum at the 24th hour after ischemia. The expression of Fas gradually increased as early as when it was at the 6th hour, reached a peak at the 24th hour, and then decreased at the 48th hour. Similarly, the expression of Fas ligand was at peak in 24-48 hours in GCL and INL of retina. Conclusions Retinal ischemia-reperfusion after transient elevated IOP induced apoptosis of cells in the retina. Fas/FasL may play an important role in the early events of the apoptotic pathways. bFGF can rescue RGCs from retinal ischemia/reperfusion injury through downregulation of the expression of Fas/FasL and may represent an important mechanism for therapeutic neuroprotection. (Chin J Ocul Fundus Dis，2003，19：160-163)