rough the ultramicroscopic observation on muscle and microcirculation, Group A,where a largeamount of DXM combined with heporin was given svstematically and locally into the femoral artery of the severed limb before replantation, and in Group B only heporin was given, and Group C and D ascontrol.The results showed that if the hormone and heparin were administred in large dosage, it wasadvantageous to reduce the tissues from reperfusion injury during delayed replantation.
OBJECTIVE To determine the role of endogenous carbon monoxide(CO) in oxidant-mediated organ injury following limb ischemia-reperfusion (I/R) in rats. METHODS: Sixty-four SD rats were divided into 4 groups: Sham group, Sham + zinc protoporphyrin (ZnPP, an inhibitor of heme oxygenase activity), 2-hour ischemia followed by 4-hour reperfusion (I/R) group and I/R + ZnPP group. Carboxyhemoglobin (COHb) level in the artery blood, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in the lung, heart, liver and kidney were detected. The 24-hour survival rate of rats was studied. RESULTS: Compared with the sham group, the COHb level and MDA content significantly increased, while the SOD activity and the survival rate significantly decreased in I/R group (P lt; 0.05). Compared with the I/R group, MDA content significantly increased, while the SOD activity, the 24-hour survival rate and COHb level significantly decreased in I/R + ZnPP group (P lt; 0.05, respectively). CONCLUSION: Limb I/R could lead to the oxidant-mediated multiple organ injury accompanied by the increase of CO level which play an important role in the defense against I/R-induced remote multiple organ injury in rats.
ObjectiveTo study the relationship between hepatocellular apoptosis and glycogen contents during hepatic cold preservationreperfusion and its mechanism.MethodsBased on the model of four groups of rabbit livers with different hepatocellular glycogen contents, hepatocellular apoptosis and bax gene expression were observed during hepatic cold preservationreperfusion.ResultsApoptotic hepatocytes were obviously found in 60 minute reperfusing livers subsequent to 9 hour cold storage, and there was significant difference in the numbers of apoptotic hepatocytes among all the groups. In the same time, there was the close relationship between the levels of bax gene expression and the glycogen contents of hepatocytes.ConclusionIntracellular abundant glycogen may significantly depress the hepatocellular apoptosis during hepatic cold preservationreperfusion by decreasing hepatocellular bax gene expression.
Objective To observe the effects of basic fibroblast growth factor (bFGF) on the expression of heat shock protein 70 (HSP70) in ratrs retina after iscbemia/reperfusion injury.Methods The rat model of experimental retinal ischemia/reperfusion injury was made by increasing the intraocular pressure. Tweenty-four Wistar rats were divided into normal (3 rats) and operation group (21 rats) randomly. The latter group was subdivided into group 0 hour, 4, 8, 12, 24, 48 and 72 hours after reperfusion, in which the left eyes of the rats were in the ischemia/reperfusion groups and the right ones were in the treatment groups (bFGF 2 t~g intracameral injection). The expression of HSP70 was observed by strept avidin-biotin complex (SABC) immunohistochemistry. Results No HSP70 positive cells were found in normal group; a few of HSP70 positive cells were found 0 hour after reperfusion [20.8±4. 5) cells/mm2], and increased gradually until reached the peak 24 hours later [(111.2±4.4) cells/mm2] and then decreased gradually. Few HSP70 positive cells were found 72 hours after reperfusion. The amount of HSP70 positive cells increased in treatment group at all time courses, and the peak time was earlier and longer than that in ischemia group. HSP70 positive cells distributed extensively in retinal ganglion cell layer and inner nucleous layer. The difference of the amount of HSP70 positive cells between the two groups was significant (Plt;0.05) 8, 12, 24, 48 and 72 hours after reperfusion.Conclusion bFGF can enhance the expression of HSP70 in rat’s retina after retinal ischemia/reperfusion injury.(Chin J Ocul Fundus Dis，2004，20：37-39)
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)
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)
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.
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)
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.
ObjectiveTo investigate the effect of basic fibroblast growth factor (bFGF) on expression of apoptosisrelated genes in retinal ischemiareperfusion injury (RIRI).MethodsTwentyeight rats were divided into normal, ischemia and treatment group randomly; and the latter two groups were subdivided into 6 subgroups according to different time points: 1 hour, 6, 12, 24, 48, and 72 hours after reperfusion. The rats′ model of experimental RIRI was established. After intravitreously injected with bFGF (treatment group) or balanced saline solution (ischemia group), the expressions of wide type p53 (WTp53)，c-fos, and c-jun in each subgroups were detected by streptavidinbiotin complex of immunohistochemistry.ResultIn ischemia group, the expression of WTp53,c-fos and c-jun was found 6 hours after reperfusion, reached the peak at the 24th hour after reperfusion, kept expressing bly at the 48th hour, and decreased obviously at the 72nd hour. In treatment group, the rule of changes of expression of WTp53, c-fos and c-jun was similar to which in ischemia group, except that the expression amount was obvious decreased. There was statistical significance of the expression of WTp53, c-fos and c-jun between the ischemia and treatment group 6-48 hours after reperfusion (P＜0.05）. ConclusionThe expression of WTp53,c-fos,and c-jun in retinal ganglion cell layer and inner nuclear layer may increase led by RIRI；WTp53,c-fos,and c-jun may be involved in the generant mechanisms of RIRI by playing parts in apoptosis；bFGF can inhibit the increase of expression of WTp53,c-fos,and c-jun in RIRI.Thus, which may has therapeutic effect on RIRI.( Chin J Ocul Fundus Dis,2005,21:310-313)