AIMTo investigate the effect of taurine on nitric oxide synthase (NOS) activity and nitric oxide products (NO2 /NO3 ) content in myocardium and plasma during shock resuscitation.

METHODSTwenty-four rabbits were divided randomly into 3 groups (n=8): control group, shock group, taurine group. The model of hemorrhagic shock resuscitation was used. The activities of nitric oxide synthase (NOS), lactate dehydrogenase (LDH) and the contents of nitric oxide products (NO2- /NO3-) in plasma were observed before shock and shock 1.5 hours, after resuscitation 1 hour, 2 hours and 3 hours. The activities of NOS and the contents of NO2-/NO3- in myocardium homogenate were measured after resuscitation 3 hours. Meanwhile, pathologic samples treated routinely.

RESULTS(1) During resuscitation, the activities of NOS, LDH and the contents of NO2- /NO3- in plasma of shock group were significantly higher than that of before shock and shock 1.5 hours (P < 0.01). (2) After resuscitation 3 hours, the activity of NOS and the contents of NO2- / NO3 in myocardium of shock group were significantly higher than that of control group (P < 0.01). The cardiac myocyte appeared edema, fatty degeneration. (3) All the changes of above mentioned could be attenuated by intravenous injection taurine (40 mg/kg) (P < 0.01).

CONCLUSIONThese results suggest that the NOS activation and NO release may mediated myocardium injury induced by shock resuscitation, taurine can ameliorate the myocardium injury, which may be related to decreasing the generation of NO.

Animals ; Myocardium ; metabolism ; pathology ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase ; metabolism ; Plasma ; metabolism ; Rabbits ; Resuscitation ; Shock, Hemorrhagic ; blood ; metabolism ; Taurine ; pharmacology

OBJECTIVETo observe the effects of pravastatin on platelet-derived nitric oxide system in hypercholesterolemia (HC) and atherosclerosis (AS) in rabbits, and the relationship between these changes and atherosclerosis courses.

METHODSThirty male New Zealand white rabbits were randomly divided into three groups, 12 in group A, 12 in group B, and 6 in group C. All of them were fed daily with cholesterol-rich food during the first 12 weeks. In addition, in group A, pravastatin (10 mg) was orally administered daily. At the end of the 12th week, 6 in group A and B were killed randomly and their aortas were removed and the pathologic changes were observed. In the following 12 weeks, food enriched with cholesterol was substituted with normal food in all three groups. Pravastatin treatment was continued or started in the remaining members of group A and group B, but not in group C. At the end 24th week, all rabbits were killed and their aortas were examined for the fatty-streaks or atherosclerotic plaques. The expressions of endothelial NOS (eNOS) mRNA and inducible NOS (iNOS ) mRNA, NOS activity, NO production and the level of the serum lipids were measured at 0, 6th, 12th, 18th and 24th week.

RESULTSThe expression levels of platelet-derived NOS mRNA, eNOS mRNA ratio in group A had no difference at above time points, while in group B were reduced significantly at 6th week and 12th week compared with at 0 week (P <0.01), and increased at 18th week and 24th week compared with 12th week (P <0.05). The expression levels of eNOS mRNA in group C were reduced at 6th, 12th and 18th, 24th week compared with 0 week (P <0.05 and P <0.01, respectively), and were reduced in groups B and C compared with group A at 6th ,12th week (P < 0.05) and increased in group A and B compared with group C at 18th, 24th week (P <0.01). The expression levels of iNOS/mRNA among the three groups had no difference. Pathologic finding of the arteries: AS was not found in group A from the 12th to 24th week. While in group B, there were a lot of fatty-streaks on the entire intima of all large arteries at the 12th week. There were also fatty-streaks in the ascending aorta, but were improved at the 24th week. In group C, there were marked plaques in the entire aorta at the 24th week.

CONCLUSIONSThe expressions of platelet-derived eNOS mRNA, NOS activity, NO production are decreased in HC or AS rabbits. Pravastatin can up-regulate expressions of platelet-derived eNOS mRNA, NOS activity, leading to preventing or improving the pathological courses of AS.

Animals ; Atherosclerosis ; blood ; pathology ; Blood Platelets ; metabolism ; Disease Models, Animal ; Male ; Nitric Oxide ; blood ; genetics ; Nitric Oxide Synthase ; blood ; genetics ; Pravastatin ; pharmacology ; RNA, Messenger ; genetics ; Rabbits

BACKGROUND: To determine whether nitric oxide (NO) could inhibit activation of platelets stored in a cold or frozen state, we measured platelet P-selectin expression and platelet-bound fibrinogen in platelet-rich plasma (PRP) with S-nitrosoglutathione (GSNO) (Sigma, USA) by flow cytometry. METHODS: PRP was prepared by centrifuging venous blood collected in a 3.2% sodium citrate tube from 10 healthy donors. It was aliquotted into 4 groups (no cryoprotectant, GSNO, GSNO/dimethyl sulfoxide [DMSO] [Sigma], and DMSO), and stored at room, cold and freezing temperatures for 24 hrs. We performed a flow cytometric analysis of all specimens stained with FITC-fibrinogen and PE-CD62P monoclonal antibodies (Becton Dickinson, USA). The results were compared according to the storage temperature and agonist among 4 groups. RESULTS: GSNO inhibited significantly the activation of frozen platelets, but not in the presence of DMSO. GSNO was also shown to preserve the aggregability of frozen platelets because in the presence of GSNO the delta percent change of P-selectin expression and fibrinogen binding of frozen platelets increased significantly irrelevant to DMSO. CONCLUSIONS: GSNO inhibited the activation of frozen platelets and preserved the platelet aggregability; therefore, it may be used as a protectant for platelet cryopreservation.
Adult ; Blood Platelets/*drug effects/metabolism ; Cryopreservation/*methods ; Female ; Fibrinogen/metabolism ; Flow Cytometry ; Free Radical Scavengers/pharmacology ; Humans ; Male ; Nitric Oxide/metabolism ; Nitric Oxide Donors/*pharmacology ; P-Selectin/metabolism ; Platelet Aggregation/drug effects ; Platelet Aggregation Inhibitors/pharmacology ; S-Nitrosoglutathione/*pharmacology

An enhanced formation of nitric oxide(NO), due to the induction of inducible nitric oxide synthase(iNOS), has been implicated in the pathogenesis of shock and inflammation, but its role in acute pancreatitis still remains controversial. To clarify the role of NO in acute pancreatitis, the present experiment investigated the expression of iNOS and the effect of NOS inhibition on cerulein-induced pancreatitis in rats. Group I received intraperitoneal (ip) injection of normal saline. Group II received two ip injections of cerulein (20 microgram/kg). Group III received injections of N(G)-nitro-L-arginine methyl este(L-NAME) (30 mg/kg) with cerulein. Group IV received L-arginine(250 mg/kg) with cerulein and L-NAME. The expression of iNOS in the pancreas was examined by western blot analysis. The plasma concentration of NO metabolites was measured. The severity of pancreatitis was assessed by measuring serum amylase, pancreas water content and histopathological examination. Compared with controls, the cerulein group displayed significantly increased expression of iNOS and raised plasma NO metabolites. Treatment with L-NAME significantly decreased hyperamylasemia, plasma NO level, and the extent of pancreatic injury. Treatment with L-arginine reversed the effects of L-NAME. These findings suggest that an enhanced formation of NO by iNOS plays an important role in the development of acute pancreatitis, and inhibition of NO production has the beneficial effects in reducing pancreas injury.
Amylases/blood ; Animals ; Arginine/pharmacology ; Blotting, Western ; Caerulein/*pharmacology ; Enzyme Inhibitors/pharmacology ; Inflammation ; Male ; NG-Nitroarginine Methyl Ester/pharmacology ; Necrosis ; Nitric Oxide/metabolism/*physiology ; Nitric-Oxide Synthase/metabolism ; Pancreatitis/*chemically induced/*metabolism ; Rats ; Rats, Sprague-Dawley

The role of nitric oxide (NO) in the ocular surface remains unknown. We investigated the conditions leading to an increase of NO generation in tear and the main sources of NO in ocular surface tissue. We evaluated the dual action (cell survival or cell death) of NO depending on its amount. We measured the concentration of nitrite plus nitrate in the tears of ocular surface diseases and examined the main source of nitric oxide synthase (NOS). When cultured human corneal fibroblast were treated with NO producing donor with or without serum, the viabilities of cells was studied. We found that the main sources of NO in ocular surface tissue were corneal epithelium, fibroblast, endothelium, and inflammatory cells. Three forms of NOS (eNOS, bNOS, and iNOS) were expressed in experimentally induced inflammation. In the fibroblast culture system, the NO donor (SNAP, S-nitroso-N-acetyl-D, L-penicillamine) prevented the death of corneal fibroblast cells caused by serum deprivation in a dose dependent manner up to 500 micrometer SNAP, but a higher dose decreased cell viability. This study suggested that NO might act as a doubleedged sword in ocular surface diseases depending on the degree of inflammation related with NO concentration.
Animals ; Apoptosis/drug effects/physiology ; Aqueous Humor/metabolism ; Blood Proteins/pharmacology ; Cell Survival/drug effects/physiology ; Cells, Cultured ; Epithelium, Corneal/*cytology/*enzymology ; Fibroblasts/cytology/enzymology ; Humans ; Nitric Oxide/biosynthesis/*physiology ; Nitric Oxide Donors/pharmacology ; Nitric Oxide Synthase/metabolism ; Nitric Oxide Synthase Type I ; Nitric Oxide Synthase Type II ; Nitric Oxide Synthase Type III ; Penicillamine/*analogs & derivatives/pharmacology ; Peroxynitrous Acid/biosynthesis ; Rabbits ; Tears/metabolism ; Uveitis/metabolism

OBJECTIVETo examine the effect of H2S donor, sodium hydrosulfide (NaHS), on ET-1 level in plasma and aorta in rats with atherosclerosis (AS).

METHODThirty male rats, weighting 200-220 g, were randomly divided into AS, AS+NaHS and control groups, n = 10 in each group.Rats were given a single dose of vitamin D3 (700 000 U/kg) in the first three days and fed with a high-cholesterol diet for 8 weeks to induce AS. Rats in AS+NaHS group were intraperitoneally injected with an H2S donor NaHS, at a dose of 56 µmol/(kg·d) for 8 weeks. At the end of the experiment for 8 weeks, all the rats were sacrificed. The plasma was collected and the aorta and coronary tissues were isolated. The atherosclerotic lesions in both aorta and coronary arteries were detected using oil red O method. H2S concentration in plasma was determined with sulfide-sensitive electrode method. ET-1 levels in plasma and aorta were calculated by radioimmunoassay kit and the localization of ET-1 in the aorta was detected by immunohistochemistry. Plasma nitric oxide synthase (NOS), endothelial NOS (eNOS), inducible NOS (iNOS) were detected with colorimetry.

RESULTAS plaque area in root of aorta of rats in AS group, AS+NaHS group and control group were (11.6±3.3)%, (1.6±1.1)%, (0.0±0.1)% respectively. The difference in AS plaque area in root of aorta among the three groups was statistically significant (F=97.675, P < 0.05). AS plaque area in coronary artery of rats in AS group, AS+NaHS group and control group were (21.4±5.7)%, (4.8±2.5)%, (0.0±0.0)% respectively. The difference in AS plaque area in coronary artery among the three groups was statistically significant (F=97.519, P < 0.05). Plasma H2S level in rats of AS group ((22.0±3.1) µmol/L) was significantly lower than that of control group ((27.9±1.0) µmol/L) and AS+NaHS group ((33.3±6.2) µmol/L, all P < 0.05). Compared with control group ((70.0±10.7) ng/L), plasma ET-1 in rats of AS group ((89.6±14.2) ng/L) and AS+NaHS group ((93.1±15.5) ng/L, P both < 0.05) were increased. However, there was no significant difference in plasma ET-1 content in rats between AS+NaHS group and AS group (P > 0.05). Compared with control group ((3.8±1.2) ng/g), ET-1 content in aorta in rats of AS group ((11.9±4.9) ng/g) and AS+NaHS group ((8.2±2.5) ng/g, both P < 0.05) were increased, and ET-1 content in aorta in rats of AS+NaHS group was decreased compared with AS group (P < 0.05). Immunochemistry results showed that ET expression in cytoplasm in aortic endothelial cells in rats of AS group was strengthened, while ET expression in rats of control group and AS+NaHS group was weak. NOS activity of rats in control group, AS group and AS+NaHS group was (25.4±5.6), (51.8±10.0) and (27.6±6.5) U/ml, eNOS activity (15.3±6.2), (4.5±2.7) and (8.7±3.9) U/ml, and iNOS activity (9.9±4.0), (47.3±10.7) and (19.0±5.2) U/ml, respectively.Differences among the three groups were statistically significant (NOS activity: F=37.231, P < 0.05, eNOS activity: F=14.600, P < 0.05, and iNOS activity: F=72.131, P < 0.05).

CONCLUSIONH2S donor NaHS reduced the AS plaque in AS rats. The mechanisms might involve the protective effect of H2S on the vascular endothelial cell, decreasing ET-1 production in aortal endothelium of atherosclerotic rats.

Animals ; Aorta ; metabolism ; pathology ; Atherosclerosis ; metabolism ; pathology ; Coronary Vessels ; pathology ; Disease Models, Animal ; Endothelin-1 ; blood ; metabolism ; Hydrogen Sulfide ; pharmacology ; Male ; Nitric Oxide Synthase Type II ; metabolism ; Nitric Oxide Synthase Type III ; metabolism ; Random Allocation ; Rats ; Sulfides ; pharmacology

AIMTo detect the changes of inducible nitric oxide synthase (iNOS) expression in liver following ischemia/reperfusion (I/R) of hindlimbs and to elucidate their significance.

METHODSI/R was established using the occlusion of the femoral arteries for 4 h and reopening for 2-24 h in rats. The expression of iNOS mRNA, and iNOS protein and the nitrotyrosine (NT), a marker of peroxynitrite (ONOO-), in liver tissue were detected with reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemical technique, respectively. The liver superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents were spectrophotometrically measured. The observation of pathologic changes of liver was made following the inhibition of iNOS by aminoguanidine (AG).

RESULTSCompared with control groups, the relative expression level of iNOS mRNA significantly increased in I/R group. There were more iNOS positive hepatocytes and more NT positive hepatocytes in I/R group than control groups. The contents of MDA markedly increased, while the activity of SOD significantly decreased in I/R group, compared with those in the control groups. The pathologic changes of rat liver became milder in I/R group following the inhibition of iNOS by AG.

CONCLUSIONThe expressions of iNOS mRNA and protein in liver are significantly upregulated, excess induction of iNOS-NO is contributed to the liver injury during the I/R of hindlimbs.

Animals ; Guanidines ; pharmacology ; Hindlimb ; blood supply ; Liver ; blood supply ; metabolism ; Male ; Malondialdehyde ; analysis ; Nitric Oxide ; metabolism ; Nitric Oxide Synthase Type II ; metabolism ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; metabolism ; Superoxide Dismutase ; analysis

Blood Platelets ; enzymology ; Diabetes Mellitus, Type 2 ; enzymology ; Enzyme Activation ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; pharmacology ; Nitric Oxide Synthase ; metabolism ; Nitric Oxide Synthase Type III ; Phosphorylation ; Pravastatin ; pharmacology ; Serine ; metabolism

OBJECTIVETo investigate the expressions of sphingosine-1-phosphate receptors 1-3 (S1P1- 3) in the corpus cavernosum of castrated male rats and its relationship with the NOS/NO/cGMP and RhoA/Rho kinase signaling pathways.

METHODSWe equally randomized 18 eight-week-old healthy male SD rats into a sham-operation control, a castration, and a testosterone replacement (TR) group and harvested the bilateral testes and epididymides from the rats in the latter two groups, followed by 4 weeks of subcutaneous injection of testosterone propionate at 3 mg per kilogram of the body weight per day for those in the TR group and that of plant oil for those in the control and castration groups. At the age of 12 weeks, we measured the serum testosterone (T) level and maximum intracavernous pressure/mean arterial pressure (ICPmax/MAP) of the animals and determined the expressions of SlP1-3, eNOS, P-eNOS, ROCK1, and ROCK2 in the corpus cavernosum by Western blot and immunohistochemistry.

RESULTSThe serum T level was significantly decreased in the rats of the castration group as compared with those of the control and TR groups ([0.41 ± 0.04] vs [16.01 ± 1.02] and [15.84 ± 1.32] nmol/L, P < 0.01), with no statistically significant difference between the latter two groups. The ICPmax/MAP at 0 V, 3 V, and 5 V electric stimulation was remarkably lower in the rats of the castration group (0.088 ± 0.014, 0.323 ± 0.014, and 0.432 ± 0.012) than in those of the control group (0.155 ± 0.011, 0.711 ± 0. 010, and 0.819 ± 0.024) and TR group (0.153 ± 0.012, 0.696 ± 0.017, and 0.763 ± 0.027) (P < 0.01), with no significant difference between the latter two groups. With GAPDH as internal control, the animals of the castration group showed markedly reduced expressions of S1P1 ([49.99 ± 3.39]%), eNOS ([46.82 ± 3.81]%) , and P-eNOS ([45.42 ± 4.35]%) in comparison with those in the control group ([72.57 ± 3.06], [89.76 ± 3.98], and [82.53 ± 8.92] and TR group ([71.77 ± 4.43], [87.19 ± 4.23], and [79.82 ± 7.38]%) (P < 0.01) , while the expressions of S1P2, S1P3, ROCK1, and ROCK2 were significantly upregulated in the castration group ([82.35 ± 4.13], [61.03 ± 5.14], [74.50 ± 4.02], and [69.83 ± 5.75]%) as compared with those in the control group ([41.67 ± 1.68], [31.66 ± 2.67], [35.69 ± 5.56], and [39.85 ± 7.17]%) and TR group ([42.80 ± 3.87], [32.25 ± 4.22], 38.06 ± 5.21], and [42.36 ± 4.44]%) (P < 0.01).

CONCLUSIONAndrogen deficiency induces significant reduction of ICPmax/ MAP in male rats, which is possibly associated with the decline of S1P1 in the corpus cavernosum, inhibition of the eNOS/NO/cGMP signaling pathway, increased expressions of S1P2 and S1P3, and activation of the RhoA/Rho kinase signaling pathway.

Animals ; Male ; Nitric Oxide Synthase Type III ; metabolism ; Orchiectomy ; Penis ; metabolism ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Receptors, Lysosphingolipid ; metabolism ; Testosterone ; blood ; pharmacology ; rho-Associated Kinases ; metabolism

AIMTo investigate the changes of the brain NSE, S100 and ultrastructure and effect of ligustrazine in rats of chronic hypoxia and hypercapnia.

METHODSThirty rats were randomly divided into three groups: control group (A), hypoxia hypercapnia group (B), hypoxia hypercapnia added ligustrazine group (C). The brain NSE, S100 and ultrastructure were observed in rats using the technique of immunohistochemistry and electronic microscope.

RESULTS(1) The mPAP was significantly higher in rats of group B than that of group A and it was much lower in rats of group C than that of group B. Differences of mCAP were not significant in three groups. (2) Serum NO of group B was significantly lower than that of group A, Serum NO of group C was higher than that of group B. (3) Immunohistochemistry showed the average value of integral light density (LD) of NSE and S100 was significantly much lower in rats of group B than that of group A and it was higher in rats of group C than that of group B. (4) The neuron and astrocyte of group B showed vacuolar degeneration and the myelin sheath showed separate. Damage of neuron is alleviated in rats of group C.

CONCLUSIONThe hypoxia hypercapnia could induce damage of neuron and astrocyte in rats. The ligustrazine may be useful in protecting against hypoxia hypercapnia brain damage.

Animals ; Brain ; drug effects ; metabolism ; pathology ; Hypercapnia ; metabolism ; Hypoxia, Brain ; metabolism ; physiopathology ; Male ; Nitric Oxide ; blood ; Pyrazines ; pharmacology ; Rats ; Rats, Sprague-Dawley ; S100 Proteins ; metabolism