To investigate changes of serum nitric oxide (NO) levels and therapeutic effects of sodium nitroprusside (SNP) in acute hemorrhagic necrotizing pancreatitis (AHNP) in rats, one hundred and twenty Wistar rats were divided into three groups randomly (forty in each group) animal models of AHNP group were produced by retrograde injection of 5% sodium taurocholate into pancreatobiliary duct.In the treatment group SNP (0.05mg/100g) was injected intraperitoneally after AHNP models established and then repeated three hours later. In the control group only retrograde injection of normal saline (0.5ml) into pancreatobiliary duct was performed. The results showed: compared with the treatment group, serum NO and SOD levels were significantly lower in AHNP group (Ｐ＜0.05); serum amylase levels and pancreatic indexes were markedly higher in AHNP (Ｐ＜0.01 and Ｐ＜0.05 respectively);the mortality in 24 hours was significantly higher and survival time was significantly shorter in AHNP group (Ｐ＜0.01).Pathologic changes of pancreas were significantly severe in AHNP group. From the above results we can draw the conclusion that NO plays an important role in the pathogenesis of AHNP and SNP has therapeutic effects on AHNP in rats.
Objective:To observe the inhibited effect and its mechani sm of estro gen on lightinduced apoptosis of retinal photoreceptor cells. Methods:Twenty female Sprague-Dawley rats were randomly divided into two groups: ovariectomized (OV) group and OV and estrogen (E2) replacement (OV+E2) group, with 10 rats in each group. All of the rats were exposed to the cyclic illumination under 12 hou r light and 12 hour dark condition with the light intensity of (600plusmn;35.4) lx ( a total of 14 times). All of the right eyes were extracted and the thickness of r etinal outer nuclear layer (ONL) was measured. Terminal deoxynucleotidyl Transfe rasemediated dUTP nick end labeling (TUNEL) method was used to evaluate positi v e apoptosis cells in ONL. The expression of nitric oxide synthase (NOS) in retin al cells was detected by immunohistochemistry with image analysis method. Results:The thickness of ONL in OV group was obviously thinner than that in the OV+ E2 group. The number of positive apoptosis of the cells was (0.0275plusmn;0.0069) c el ls/mu;m2 in OV group and (0.0162plusmn;0.0054) cells/mu;m2 in OV+E2group; the di fferen ce between the two groups was significant (t=4.1370，P=0.0012). The values o f in tegral optical density of NOS positively stained cells in retinal inner nuclear layer was (0.3675plusmn;0.0662) in the OV group and (0.2941plusmn;0.0350) in OV+E2 group ; the difference between the two groups was significant (t=3.4885, P=0.0031). Conclusion:Estrogen can protect retina from light injuries by regu lating NOS synthesis and inhibiting apoptosis of photoreceptor cells.