Expression of Hedgehog signaling molecules in rat livers after partial hepatectomy

AIM: To detect the expression of Hedgehog signaling molecules in rat livers after partial hepatectomy. METHODS: The model of rat partial hepatectomy was established by resecting the middle and left lobes of the liver. Eighteen male Sprague-Dawley rats were divided into 3 groups: sham operation group (group A), partial hepatectomy group 1 (group B) and partial hepatectomy group 2 (group C). Hepatic tissues were collected 24 h after the operation in group A and group B, and 48 h after the operation in group C. The expression of Ki-67,Sonic Hedgehog(Shh),Indian Hedgehog(Ihh) and Glioblastoma-2(Gli-2) in the hepatic tissues were detected by immunohistochemical staining and Western blotting. RESULTS: The edema and spotty necrosis in the hepatic tissues were observed in group B and group C by HE staining. The cells of different dividing stages were found in the hepatic tissues of group C. Compared with group A, the expression of Ki-67, Shh, Ihh and Gli-2 in group B (P<0.01) and group C (P<0.01) was significantly elevated, and the expression levels in group C were higher than those in group B (P<0.01). CONCLUSION: Hedgehog signaling in rat livers may be activated after partial hepatectomy and stimulate liver regeneration.     

Protective effects of aFGF compound solution on rat liver in hypothermic preservation

AIM: To investigate the protective effects of human acidic fibroblast growth factor (aFGF) on hypothermic preservation of rat liver. METHODS: Twenty-four Wistar rats were randomly divided into 2 groups (n=6): hypertonic citrate adenine (HCA) solution control group and experimental group (aFGF compound solution, containing 40 μg/L aFG_14-154 in HCA solution). The isolated livers were preserved in corresponding solution for 12 h or 24 h, and the content of malondialdehyde (MDA), the activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), and the changes of liver weight in the 2 groups were analyzed. The histopathological changes of the livers were also examined. RESULTS: Compared with HCA control group, the levels of ALT, AST and MDA and the changes of liver weight were significantly decreased in experimental group (24 h), and the changes of liver histopathology were obviously alleviated in experiment group. CONCLUSION: aFGF can reduce rat hepatic injury. The protective effects of aFGF may be related to attenuating cell swelling and improving the capacity of anti-oxidative damage in the liver.     

Pretreatment of hypertonic saline attenuates the hepatic ischemia reperfusion injury induced by neutrophils

AIM: To explore the effect of the pretreatment of hypertonic saline (HTS) in hepatic ischemia reperfusion (I/R) injury.METHODS: The rats were divided into sham group (sham group), ischemia reperfusion group (IR group) and pretreatment of hypertonic saline group (HTS group). Partial hepatic ischemia reperfusion model was used. The rats were sacrificed at the time of 1 h, 3 h, 6 h, 12 h and 24 h after reperfusion in each group, respectively. Blood samples were obtained to examine ALT. The expression of the CD11b/CD18 (Mac-1) on the neutrophils was analyzed by flow cytometry. RT-PCR and Western blotting were used to examine the expression of intercellular adhesion molecule-1 (ICAM-1) in livers and chromatometry was performed to detect the activity of myeloperoxidase (MPO) in livers. The morphology of hepatocytes and the structure of sinusoid were observed by histological examinations. RESULTS: ① HTS pretreatment decreased the level of ALT at the time points of 3 h, 6 h and 12 h after reperfusion (P<0.05). ② Mac-1 expression in HTS group was lower at 6 h and 12 h after reperfusion compared with IR group (P<0.05). ③ MPO activity in HTS group was lower at 6 h, 12 h and 24 h compared with IR group (P<0.05). ④ RT-PCR and Western blotting analysis indicated that the pretreatment of HTS inhibited the expression of ICAM-1 in livers after reperfusion. ⑤ Moderate hepatocyte swelling and few neutrophil infiltration were observed in HTS group.CONCLUSION: Pretreatment with HTS has the effect on hepatic ischemia reperfusion injury by inhibiting the expression of Mac-1 on circulating neutrophils and the expression of ICAM-1 in the liver.     

The protection of the hepatic ischemic preconditioning is concerned with the NO/ET-1 system

AIM: To study the relationship between the disturbance of nitric oxide/endothelin-1(NO/ET-1) and hepatic ischemia/reperfusion(I/R) injury as well as the regulation of NO/ET-1 system by hepatic ischemic preconditioning(IPC). METHODS: The changes of NO/ET-1 system and their relationship with hepatic I/R injury were compared between I/R group and IPC+I/R group in a rat hepatic I/R model. Two hours after reperfusion, the liver tissues were detected by RT-PCR to see whether there was inducible nitric oxide synthase (iNOS) mRNA expression. RESULTS:In the acute phase of hepatic reperfusion, the ratio of NO/ET-1 was reduced, which was due to a significant reduction of NO₂^-/NO₃^- (the metabolic product of NO) and significant elevation of ET-1 in the blood plasma. The content of ALT, AST, LDH and TNF-α in blood plasma, and of MDA in liver tissue were increased but ATP in liver tissue was reduced, the hepatic damage was deteriorated. The protection of the hepatic IPC was concerned with the elevation of the ratio of NO/ET-1 caused by the elevation of NO₂^-/NO₃^-, and reduction of ET-1 as well. There was no iNOS mRNA detected in the liver tissues.CONCLUSION: Hepatic I/R injury is related to the disturbance of NO/ET-1. The protection of the hepatic IPC in the acute phase might be conducted by its regulation of NO/ET-1 system. The cNOS rather than the iNOS generated the NO in this situation.     

Endothelin-1 and eNOS expression in pulmonary aterioles of patients with congenital heart diseases with pulmonary hypertension

AIM: To clarify the role of eNOS and ET-1 in development of pulmonary hypertension (PH) associated with congenital heart diseases. METHODS: 40 patients were randomly divided into three groups: severe or moderate PH group (group A, 12 cases), slight PH group (group B, 14 cases) and normal group (group C, 14 cases). ET-1 and eNOS were examined by using the technique of immunohistochemistry. RESULTS: ① Plasma ET-1 concentration was significantly higher in group A and B than that in group C (P<0.01). Serum NO concentration in group A and B was significantly lower than that in group C (P<0.01). ② The proliferation of medial smooth muscle cells and collagenous fibers of pulmonary arteriole in patients with PH were observed by electron microscopy. ③ ET-1 in pulmonary arteriole was significantly higher in group A and group B than that in group C (P<0.01). eNOS in pulmonary arteriole was significantly lower in group A and group B than that in group C (P<0.01). CONCLUSION: ET-1 and eNOS may play an important role in the pathogenesis of PH.     

Effects of aminophylline used in the early stage of resuscitation on adenosine and vaso-active factors

AIM: To investigate the effects of aminophylline used early in resuscitation on achievement ratio of resuscitation, the concentrations of plasma norepinephrine (NE), adenosine and nitric oxide (NO), and the levels of cardiac tissue endothelin-1 (ET-1) and adenosine in rats with sudden cardiac arrest. METHODS: Sixty SD rats were randomly divided into three groups: operated control (group A), epinephrine treatment (group B), and epinephrine plus aminophylline treatment (group C). Each group had 20 rats. The concentrations of plasma NE, adenosine and NO, and the levels of cardiac tissue ET-1 and adenosine were examined in group A and 30 min after survived in group B and group C. RESULTS: The duration of circulation recovered in group C was less than that in group B, significantly (P＜0.05). The rate of return of spontaneous circulation and survival to 30 min was achieved in 75% and 70% in group C, while those were achieved in 60% and 55% in group B, respectively (P>0.05). The concentrations of plasma adenosine and NE, and the levels of cardiac tissue ET-1 and adenosine in group B and group C were higher than those in group A significantly (P<0.05). The concentration of NO in group B was also higher than that in group A (P<0.01). The levels of plasma NO and cardiac tissue ET-1 in group C was lower than those in group B significantly (P＜0.05). CONCLUSION: Aminophylline as adenosine receptor antagonist used early in resuscitation not only increases the achievement ratio of resuscitation, but also decreases the levels of ET-1 and NO, so improves after-resuscitation syndrome.     

Effects of peritoneal cooling on inflammation after cardiopulmonary resuscitation in rabbits

AIM:To explore the effects of different cooling methods on systemic inflammation after cardiopulmonary resuscitation(CPR) in New Zealand rabbits. METHODS:Ventricular fibrillation in 48 adult New Zealand rabbits was induced by alternating current and was resuscitated after cardiac arrest for 5 min. The rabbits were randomly divided into 4 groups according to the way of cooling methods:normothermia group(NT), peritoneal cooling group(PC), surface cooling group(SC) and local cooling group(LC). The plasma concentrations of tumor necrosis factor α(TNF-α) and interleukin-6(IL-6) were measured in each group at different time points after return of spontaneous circulation(ROSC). The liver tissues were removed 12 h after ROSC, and the levels of NF-κB p65 and NF-κB p50 were tested by Western blotting. The survival time was recorded and compared 96 h after ROSC. RESULTS:The plasma concentration of TNF-α in PC group was lower than that in NT group 4 h, 8 h and 12 h after ROSC, and was also lower than that in SC group and LC group 12 h after ROSC. The level of IL-6 in PC group was lower than that in NT group 2 h, 4 h, 8 h and 12 h after ROSC, while there was no difference between the other 2 groups. The levels of p65 and p50 in PC group were lower than those in other groups(P<0.05), while there was no difference between the other 3 groups. The cumulative survival rate after ROSC in PC group was higher than that in NT group, SC group and LC group. CONCLUSION:The novel peritoneal cooling rapidly induces and maintains mild hypothermia, and decreases the peritoneal temperature quickly, thus inhibiting liver NF-κB activation, reducing the releases of TNF-α and IL-6, subsequently relieving systemic inflammation after ROSC and prolonging rabbit survival.     

Effects of Ca2+on the releases of ET-1, NO and PGI2 from bovine coronary artery endothelial cells during hypoxia

AIM: To explore the mechanism of ET-1, NO and PGI² release from coronary artery endothelial cells(CAEC) induced by acute hypoxia. METHODS: Bovine coronary artery endothelial cells were cultured and [⁴⁵ Ca²⁺] was used to investigate the difference of calcium uptake between normoxia group and hypoxia group(3% O₂). The contents of ET-1, NO and PGI² in media of normoxia group, hypoxia group and hypoxia + verapamil group were measured 24 h after hypoxia. RESULTS: [ ⁴⁵ Ca²⁺] uptake by CAEC in hypoxia group was 1.9 times more than normoxia group(P< 0.01). Hypoxia + verapamil group released more PGI², ET-1 and less NO than hypoxia group(P< 0.05). CONCLUSION: Changes of ET-1, NO and PGI² releases during hypoxia may be caused by the inflow of Ca²⁺ into coronary artery endothelial cells.     

Effect of hydrogen sulfide on airway inflammation induced by ozone in mice

AIM: To investigate the effect of hydrogen sulfide (H₂S) on airway inflammation induced by ozone (O₃) exposure and its mechanisms.METHODS: C57BL/6 mice (n=32) were randomly divided into control group, O₃ group, NaHS+O₃ group and NaHS group. The mice in O₃ group and O₃+NaHS group were exposed to 2.14 mg/m³ O₃ for 3 h on days 1, 3 and 5, while the mice in control group and NaHS group were exposed to filtered air. NaHS (14 μmol/kg) was administered intraperitoneally to the mice in NaHS group and O₃+NaHS group 30 min before each exposure. After the last exposure for 24 h, the airway responsiveness was determined, and bronchoalveolar lavage fluid (BALF) was collected for counting inflammatory cells and measuring total protein concentration. The lung tissues were collected for observing the morphological changes with HE staining. The levels of interleukin-6 (IL-6), interleukin-8 (IL-8), malondialdehyde (MDA) and NF-κB p65 protein in the lungs were determined.RESULTS: Compared with control group, the airway responsiveness, inflammatory cells, protein concentration, inflammation score, levels of IL-6, IL-8, MDA and NF-κB p65 in O₃ group increased significantly, but these in NaHS+O₃ group decreased compared with O₃  group.CONCLUSION: The present findings suggest that H₂S attenuates O₃ induced airway inflammation by inhibiting NF-κB expression and preventing lipid peroxidation.     

Inhibitory effect of hydrogen sulfide (H2S) on cultured rat aortic smooth muscle cells

AIM:To explore the effects of hydrogen sulfide (H₂S) on proliferation of vascular smooth muscle cells (VSMC) stimulated by endothelin (ET-1, 10^-7mol/L) and mitrogen-activated protein kinase (MAPK) activity in VSMCs.METHODS:Cultured VSMCs were divided into six groups: (1) control group, (2) serum group, (3) endothelin group, (4) NaHS groups, (5) serum+NaHS group, and (6) endothelin+NaHS group. VSMC proliferation was measured by[³H]-TdR incorporation and MAPK activity in VSMC was determined by radioactivity assay.RESULTS:ET-1 increased VSMC[³H]-TdR incorporation by 2.39 times (P＜0.01) and MAPK activity by 1.62 times(P＜0.01), as compared with control. H₂S (5×10^-5-5×10^-4mol/L) decreased VSMC[³H]-TdR incorporation and MAPK activity by 16.8%-37.4% and 7.4%-33.6%, respectively (P<0.05 or P＜0.01).CONCLUSION:This study demonstrates that H₂S inhibits ET-1-induced proliferation of VSMC, which might be mediated by the inhibition of MAPK.     

Intervention of Lipo-PGE1 on liver blood perfusion by different time and medication: a empirical study

AIM: To explore the effect and mechanism of liposome prostaglandin E₁(Lipo-PGE₁) on liver blood perfusion by different time and medication.METHODS: Twelve healthy adult dogs were injected with Lipo-PGE₁₁ μg/kg via left small saphenous vein at speed of 0.05 μg·kg^-1·min^-1.Liver computed tomography perfusion imaging (CTPI) was performed on 0,5,15 and 30 min,and the value of hepatic arterial perfusion (HAP),portal vein perfusion (PVP) and total liver perfusion (TLP) among groups were compared.The impacts of Lipo-PGE₁ on liver haemodynamics at different time were investigated.Twenty-four health dogs were randomly divided into four groups: control group,peripheral vein group,hepatic artery group and superior mesenteric artery group.Liver CTPI was performed at 5 min after 1 μg/kg Lipo-PGE₁ administration in those groups.The values of HAP,PVP and TLP were compared and effects of Lipo-PGE₁ on liver blood flow by different medication were observed.RESULTS: The values of liver perfusion (mL·min^-1·mL^-1) at 0,5,15 and 30 min after 1 μg/kg Lipo-PGE₁ administration via vein were as follows: HAP: 0.22 ±0.65,0.24±0.65,0.22±0.69,0.22±0.06;PVP: 1.22±0.40,1.88±0.59,1.55±0.55,1.29 ±0.57;TLP: 1.44±0.42,2.12±0.61,1.77±0.56,1.51±0.58,respectively.No significant difference in HAP among groups was observed,but in PVP and TLP,significant differences (F=3.812,P<0.05;F=3.805,P<0.05) among groups were found.The values of PVP and TLP were most obviously increased at 5 min,and the values of PVP and TLP were still on the high level at 15 min and 30 min.The values of liver perfusion (mL·min^-1·mL^-1) by different medication were as fellows: HAP: 0.22±0.06,0.24±0.06,0.31±0.07,0.26±0.05;PVP: 1.28±0.38,2.33±0.41,2.37±0.55,2.83±0.94;TLP: 1.50±0.40,2.57±0.42,2.67± 0.58,3.09±0.94,respectively.No significant difference in HAP among groups (F=2.248,P>0.05) was found,but in PVP and TLP group,significant differences (F=6.892,P<0.01;F=7.802,P<0.01) among groups were observed.In addition,superior mesenteric artery group showed higher value of PVP and TLP than other methods.CONCLUSION: Lipo-PGE₁ obviously increases liver blood perfusion,especially for portal vein perfusion.Interventional technology provides an effective pathway to improve hepatic perfusion.     

Effect of bitter melon on liver fibrosis induced by carbon tetrachloride

AIM: To investigate the effects of bitter melon (BM) on liver fibrosis induced by CCl₄ in Wistar rats. METHODS: Healthy male Wistar rats were randomly divided into 4 groups (with 8 each): olive oil control group (group C), olive oil CCl₄ model group (group M), CCl₄+BM at low concentration (BM 100 g/kg, group BM-L), CCl₄+ BM at high concentration (BM 200 g/kg, group BM-H). All rats except those in group C were subcutaneously injected with CCl₄ twice a week for 8 weeks to induce liver fibrosis. After injection of CCl₄ for 8 weeks, all rats were sacrificed and the samples of blood and livers were collected. The weight ratio of liver to body was measured. The serum level of MDA and the activity of SOD were tested. The contents of total protein and albumin, the activity of GSH-Px, the content of hydroxyproline and the activity of monoamine oxidase in the liver homogenate were determined. Hepatic inflammation and collagen deposition were observed under microscope with Masson staining. RESULTS: In the rats treated with BM, the weight ratio of liver to body, the serum level of MDA, the content of hydroxyproline and the activity of monoamine oxidase in the liver homogenate were lower than those in group M (P<0.01). The serum activity of SOD, the contents of total protein and albumin, and the activity of GSH-Px in the liver homogenate were enhanced (P<0.01). The livers of the model rats had remarkable inflammatory necrosis, collagen accumulation and fibrosis. The rats in BM-treated group showed slighter hepatic injury and collagen deposition, and the liver functions were much better than those in the model group. High dose of BM showed more obvious liver-protective effects. CONCLUSION: BM attenuates liver fibrosis by its antioxidant effect and the mechanisms of reducing hydroxyproline content and monoamine oxidase activity.     

The effects of 17β-estradiol on cardiomyocyte hypertrophy induced by endothelin

AIM:To investigate the effect of 17β-estradiol (E₂) on myocardial hypertrophy induced by endothelin-1(ET-1) and the related mechanism. METHODS:Myocardial cells from neonate rats were cultured in vitro and myocardial hypertrophy model was established with ET-1.The effects of 17β-estradiol on myocardial hypertrophy were observed. The role of ERK1/2 in the effects of 17β-estradiol was also detected. RESULTS:Compared with control group,ET-1 increased cell protein content,cell surface area and ［³H］^-Leucine ［³H］^-Leu) incorporation. Pretreatment with E₂ for 24 h could inhibit the increase in cell protein content,cell surface area and ［³H］^-Leu incorporation induced by ET-1.ET-1 significantly stimulated ERK1/2 activity,which was prevented by pretreatment with E₂.Tamoxifen,estradiol receptor antagonist,partially inhibited the effect of E₂. The ability of ET-1 to stimulate ［³H］^-Leu incorporation was significantly blocked by PD98059,which could enhance the inhibitory effect of E₂ on the increase of ［³H］^-Leu incorporation in cardiomyocytes induced by ET-1.CONCLUSION:E₂ can inhibit cardiomyocyte hypertrophy induced by ET-1. This effect is mediated by estrogen receptor. ERK1/2 signal pathway is closely correlated with the inhibitory effect of E₂ on cardiomyocyte hypertrophy induced by ET-1.     

Effect of heme oxygenase-1/endogenous carbon monoxide system on restenosis of rabbit carotid artery after balloon injury

AIM: To investigate the effect of heme oxygenase-1 (HO-1)/carbon monoxide (CO) system on restenosis of carotid artery after balloon angioplasty.METHODS: Fifty rabbits were randomly divided into 5 groups: control group given normal chow (C group), sham group(Sh group), 1.5% cholesterol diet group (Ch group), 1.5% cholesterol diet plus hemin group(Hm group)and zinc protoporphyrin IX group(Zn group).The experiment lasted for 10 weeks. At the beginning of the 3rd week, the animals in Ch group, Hm group and Zn group underwent balloon injury at one side of common carotid artery.RESULTS: Compared with those in C group, the production of arterial nitric oxide (NO) and activity of constructive nitric oxide synthase (cNOS) were significantly decreased, while CO production and HO-1 expression were significantly increased (all P<0.01) in Ch group. Compared with those in Ch group, the arterial CO production and HO-1 expression in Hm group were markedly increased, while the expression of endothelin-1 (ET-1), the intimal area and the ratio of intimal area/medial area(I/M) were distinctly reduced. Compared with those in Ch group, the arterial CO production and HO-1 expression in Zn group were obviously decreased, while the expression of ET-1, the intima area and the ratio of I/M were significantly increased.CONCLUSION: The HO-1/CO system improves the endothelium function and restrains neointimal proliferation by compensating and regulating NOS/NO system and lowering ET-1 expression so as to inhibit the restenosis.     

Role of injury and phenotype shift of liver sinusoidal endothelial cells in the development of portal hypertension of cirrhosis in rats

AIM: To study the role of injury and phenotype shift of liver sinusoidal endothelial cells in the development of portal hypertension of liver cirrhosis in rats. METHODS: The rat liver cirrhosis model was established by peritoneal injection of dimethylnitrosamine (DMN) (at a dose of 10 mg·kg^-1, 3 times a week, for 4 weeks). The dynamic changes of liver cirrhosis were observed at different time points (1 day, 2 days, 3 days, 1 week, 2 weeks, 4 weeks, 6 weeks and 8 weeks). The pressure of portal vein (Ppv), the expression of CD44, von Willebrand factor (vWF), endothelin-1 (ET-1) mRNA and endothelial nitric oxide synthase (eNOS) mRNA, the serum hyaluronic acid (HA) content and liver ET-1 content were measured. RESULTS: Compared with the normal control rats, CD44 positive staining was weak in the 1 day model rats, and the numbers of fenestrae of sinusoidal endothelial cells (SECs) rapidly decreased, but serum HA content rapidly increased (P<0.05). vWF positive staining in the 2-day model rats was stronger than that in normal control rats (P<0.05). There was a positive correlation between the Ppv and the vWF expression, serum HA content in the DMN-induced liver cirrhosis rats (P<0.05). Compared with the normal control rats, ET-1 mRNA expression increased in the 2-day and 3-day model rats, and ET-1 content lightly increased. eNOS mRNA expression was stronger in the 1-day, 2-day and 3-day model rats than that in normal control rats, meanwhile eNOS always expressed at a low level. CONCLUSION: The injury and phenotype shift of SECs is a pathological basis in the development of portal hypertension of DMN-induced liver cirrhosis in rats. Imbalance of ET-1 and NO production increases intrahepatic resistance, which plays an important role in the development of portal hypertension.     

Effect of non-invasive ischemic preconditioning on nitric oxide/endothelin-1 imbalance and gas exchange impairment following limb ischemia reperfusion: a clinical study

AIM: To investigate the effects of non-invasive ischemic preconditioning on nitric oxide (NO)/endothelin-1 (ET-1) imbalance and gas exchange impairment following limb ischemia reperfusion in patients undergoing unilateral lower extremity surgery with tourniquet. METHODS: Twenty-seven patients aged 25-65 years, whose tourniquets duration varied from 1 h to 1.5 h and matched American Society of Anesthesiologists Physical Status Ⅰ-Ⅱ, were randomized into two groups: a control group (n=14) and a ischemic preconditioning group (IPC group, n=13) in which patients received three cycles of 5 min of ischemia/5 min of reperfusion before tourniquet inflation. Radial arterial blood gas, plasma malondialdehyde (MDA) and NO, serum ET-1 and interleukin-6 (IL-6) were measured just before tourniquet inflation(T0), 1 h after inflation(T1), and 0.5 h(T2), 2 h(T3), 6 h(T4), 24 h(T5) after tourniquet deflation. Meanwhile NO/ET-1 ratio, alveolar-arterial oxygen gradient (PA-aDO2) and intrapulmonary shunt (Qs/Qt) were calculated. RESULTS: In control group, arterial partial pressure of oxygen (PaO2) were decreased, while PA-aDO2 and Qs/Qt were increased significantly at T4 compared to the baselines at T0 (P<0.01). Plasma NO levels and NO/ET-1 ratios decreased gradually after tourniquets deflation and statistical significances were observed at T3 (P<0.01) with a valley at T4 (P<0.01) and recovered to baselines at T5. Serum ET-1, IL-6 and plasma MDA began to increase remarkably after T3 (P<0.05 or P<0.01), peaked at T4 and dropped slightly at T5. The changes above-mentioned could be well attenuated by the application of IPC (P<0.05 or P<0.01) except PaO2 (P>0.05). CONCLUSION: Clinical application of unilateral tourniquet within safe time limit (1.5 h) may lead to limb ischemia reperfusion and further pulmonary gas exchange impairment, which could be partially attenuated by the application of IPC via alleviating NO/ET-1 imbalance.     

Preventive effects of anti-IGFBPrP1 antibody on hepatic fibrosis in mice

AIM: To investigate the preventive effect and mechanism of anti-insulin-like growth factor binding protein related protein 1(IGFBPrP1) antibody on hepatic fibrosis induced by thioacetamide (TAA) in mice.METHODS: Twenty-four male C57BL/6 wild-type mice were randomly divided into 3 groups (n= 8 in each group): normal control group, TAA group (4 weeks) and TAA+anti-IGFBPrP1 antibody group (4 weeks). The morphological changes of liver tissues were observed. The expression levels of α-smooth muscle actin (α-SMA), transforming growth factor beta 1 (TGF-β₁), Smad3, phosphorylated Smad2/3 (p-Smad2/3), fibronectin (FN), collagen I, collagen Ⅲ and IGFBPrP1 were detected by the methods of immunohistochemistry and Western blotting.RESULTS: In TAA group (4 weeks), obvious injury of liver was observed, and the expression levels of α-SMA, TGF-β₁, Smad3, p-Smad2/3, FN, collagen Ⅰ, collagen Ⅲ and IGFBPrP1 were significantly increased as compared with normal control group (P<0.01). Compared with TAA group (4 weeks), the injury of the liver was alleviated and the expression levels of the proteins above were decreased in TAA+anti-IGFBPrP1 antibody group (4 weeks, P<0.01). IGFBPrP1 was positively correlated with TGF-β₁, Smad3, p-Smad2/3, FN and collagen I (P<0.01). CONCLUSION: Anti-IGFBPrP1 antibody prevents TAA-induced hepatic fibrosis in mice by inhibiting the activation of hepatic stellate cells, reducing the expression of p-Smad2/3 and inhibiting the TGF-β₁/ Smad3 signal transduction, thereby depressing the deposition of extracellular matrix in liver tissues.     

Effect of exogenous hydrogen sulfide on lipophagy in mouse primary hepatocytes

AIM: To evaluate the effect of exogenous hydrogen sulfide (H₂S) from GYY4137 on lipophagy in mouse primary hepatocytes. METHODS: The C57BL/6 mouse primary hepatocytes isolated and cultured by 2-step in situ perfusion method were divided into 4 groups: the cells in control group were incubated with normal medium; the cells in model group were incubated with 1.2 mmol/L oleic acid (OA) for 48 h; the cells in H₂S group or propargylglycine (PAG) group were incubated with 1.2 mmol/L OA for 48 h followed by serum-free phenol red-free RPMI-1640 medium which contained 1 mmol/L GYY4137 or 200 μmol/L PAG for 6 h. The cells were collected to conduct immunofluorescence staining of LC3 and photography under fluorescence microscope, phase-contrast microscope or transmission electron microscope. The protein expression of LC3-Ⅰ/Ⅱ in the hepatocytes was determined by Western blot. RESULTS: In contrast with the model group, the fluorescent particles of LC3, the protein expression of LC3, the number of autophagic lysosome and vacuoles in hepatocytes in H₂S group increased. CONCLUSION: In steatosis hepatocytes, exogenous H₂S promotes the lipophagy.     

Effects of IGFBPrP1 and thioacetamide on liver tissues in mice

AIM: To investigate the effects of insulin-like growth factor binding protein related protein 1(IGFBPrP1) and thioacetamide (TAA) on the liver tissues, and to identify the role of IGFBPrP1 in liver fibrosis. METHODS: Thirty-two male C57BL/6 wild-type mice were randomly divided into 4 groups (n=8 in each group): control group, recombinant murine IGFBPrP1(rmIGFBPrP1) 4 weeks group, TAA 2 weeks group and TAA 4 weeks group. The methods of hematoxylin-eosin (HE) staining, picric acid-Sirius red staining, immunohistochemistry and Western blotting were performed. RESULTS: The extensive fatty degeneration of liver cells in rmIGFBPrP1 4 weeks group was observed. The collagen deposition was found in TAA 2 weeks group. In TAA 4 weeks group, the degree of hepatic fibrosis was more serious than that in TAA 2 weeks group. The expression levels of IGFBPrP1, transforming growth factor beta 1(TGF-β₁), Smad3, p-Smad2/3, collagen Ⅲ, collagenⅠand fibronectin (FN) in liver tissues were higher in rmIGFBPrP1 4 weeks group, TAA 2 weeks group and TAA 4 weeks group than those in control group. No significant difference of the expression levels of IGFBPrP1, collagen I and FN between rmIGFBPrP1 4 weeks group and TAA 2 weeks group was observed. CONCLUSION: IGFBPrP1 plays an important role in the process of thioacetamide-induced liver fibrosis. Meanwhile, IGFBPrP1 induces excessive deposition of extracellular matrix through TGF-β₁/Smad3 pathway.     

Effects of remifentanil on monophasic action potential and transmural dispersion of repolarization in rabbit myocardium

AIM: To study the effect of remifentanil on monophasic action potential and transmural dispersion of repolarization (TDR) in the 3-layer myocardium of isolated rabbit hearts. METHODS: Adult rabbits (n=18, 2.0 ~ 2.5 kg) were used to isolate the hearts for preparing Langendorff perfusion model. The hearts were randomly divided into 3 groups after perfusion with K-H solution for 15 min: the perfusion in control group (C group) continued for 60 min; the hearts in remifentanil group (R group) were perfused with 12 μg/L remifentanil K-H solution for 60 min; the hearts in remifentanil+aminophylline group (RA group) were given 60-min perfusion of 12 μg/L K-H remifentanil+30 mg/L aminophylline. The HR and 3 layers of myocardial monophasic action potential (MAP) in the left ventricular anterior wall were recorded at time points after balanced infusion for 15 min (T₀), and continued perfusion for 15 min (T₁), 30 min (T₂) and 60 min (T₃). The monophasic action potential duration of repolarization at 90% (MAPD₉₀) and the transmural dispersion of repolarization (TDR) were calculated. The early afterdepolarization, delay afterdepolarization and arrhythmia were also observed. RESULTS: In R group, slower HR and prolonger MAPD₉₀ and TDR at T₁~T₃ were observed as compared with those at T₀ (P<0.05). R group showed slower HR and longer MAPD₉₀ and TDR than C group and RA group (P<0.05). CONCLUSION: Remifentanil slows the HR, extends the MAPD₉₀ and increases the TDR, thus being prone to induce reentry. Aminophylline makes HR faster and MAPD₉₀ shorter, thereby reducing the TDR.