OBJECTIVETo explore the effect of ERK1/2 MAPK pathway on the expression of Kv1.5 channel, a voltage-gated potassium ion channel, in rat pulmonary artery smooth muscle cells (PASMCs) and its mechanisms during the process of hypoxia.

METHODSThe PASMCs derived from SD rats were cultivated primarily. The third to sixth generation of PASMCs were divided into 5 groups randomly: (1) Normal group (N); (2) Hypoxic group (H); (3) Demethy sulfoxide(DMSO) group (HD); (4) U0126 group (HU): 10 micromol/L U0126; (5) Anisomycin group (HA): 10 micromol/L anisomycin. There were three dishes of cells in each group. The cells in normal group were cultured in normoxic incubator (5% CO2, 37 degrees C), the cells in other groups were added to 0.05% DMSO in the hypoxic incubator (5% CO2, 2% O2, 37 degrees C), all cells were cultured for 60 h. RT-PCR and Western blot were used to detected the espressions of Kv1.5 mRNA and protein in PASMCs.

RESULTSCompared with N group, the expressions of Kv1.5 mRNA and protein in H, HD and HA groups were reduced significantly (P < 0.05); Compared with H group and HD groups, Kv1.5 mRNA and protein expressions in HU group were increased sharply (P < 0.05). Compared with the HU group, Kv1.5 mRNA and protein expressions in HA groups were significantly lower (P < 0.05).

CONCLUSIONLow oxygen reduced Kv1.5 mRNA and protein expressions, U0126 could resistant the Kv1.5 channel lower expression caused by hypoxia. Anisomycin had no significant effect on Kv1.5 channel expression under hypoxia, but the expression of Kv1.5 was still significantly lower than the normal oxygen group. These data suggest that hypoxia may cause hypoxic pulmonary hypertension by interfering ERK1/2 signaling pathway to inhibit Kv1.5

Animals ; Cell Hypoxia ; Hypertension, Pulmonary ; Kv1.5 Potassium Channel ; metabolism ; MAP Kinase Signaling System ; Mitogen-Activated Protein Kinase 1 ; metabolism ; Mitogen-Activated Protein Kinase 3 ; metabolism ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; metabolism ; Oxygen ; Pulmonary Artery ; cytology ; RNA, Messenger ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo investigate the role and significance of ATP-sensitive K+ channels in the pathological process of hypoxia hypercapnia-induced pulmonary vasoconstriction (HHPV) and the relationship with ERK1/2 signal pathway in rats.

METHODSWe made the third pulmonary artery rings of SD rats, used the model of pulmonary artery rings perfusion in vitro. Under acute hypoxia hypercapnia condition, and observed the effects of the three stages of HHPV incubated by glybenclamide(Gly) and the combined application of Gly and U0126. At the same time, the values of rings' tension changes were recorded via the method of hypoxia hypercapnia conditions reactivity.

RESULTSUnder the normoxia condition, the values of the third pulmonary artery rings tension were relatively stable, but under the hypoxia hypercapnia condition, we observed a biphasic pulmonary artery contractile response compared with N group (P < 0.05, P < 0.01). When the third pulmonary artery rings incubated by Gly, it's phase II persistent vasoconstriction was enhanced compared with the H group (P < 0.05, P < 0.01), and the phase I vasoconstriction was also heightened. Moreover, under the hypoxia hypercapnia condition, U0126 could significantly relieve the phase II persistent vasoconstriction compared with HD group (P < 0.05, P < 0.01) induced by Gly, but the phase I acute vasoconstriction and the phase I vasodilation had no changes (P > 0.05).

CONCLUSIONGly may mediate HHPV via activating ERK1/2 signal transduction pathway.

Animals ; Glyburide ; pharmacology ; Hypercapnia ; metabolism ; physiopathology ; Hypoxia ; metabolism ; physiopathology ; In Vitro Techniques ; MAP Kinase Signaling System ; physiology ; Male ; Pulmonary Artery ; drug effects ; metabolism ; physiology ; Rats ; Rats, Sprague-Dawley ; Vasoconstriction ; drug effects

OBJECTIVETo investigate the effect of chloride channel blocker--niflumic acid (NFA) on the pathological process of hypoxia hypercapnia-induced pulmonary vasoconstriction in rats.

METHODSWe used the model of hypoxia hypercapnia-induced pulmonary vasoconstriction rats, and divided the second, third branch pulmonary artery rings randomly into four groups (n = 8): control group (N group), hypoxia hypercapnia group (H group), DMSO incubation group (HD group), niflumic acid group (NFA group). Under acute hypoxia hypercapnia conditions, we observed the effects of the three stages of hypoxia hypercapnia-induced pulmonary vasoconstriction (HHPV) incubated by NFA in the second, third brach pulmonary artery rings. At the same time, the values of rings' tension changings were recorded via the method of hypoxia hypercapnia conditions reactivity. And investigated the effect of NFA to HHPV.

RESULTS(1) Under the hypoxia hypercapnia condition, we observed a biphasic pulmonary artery contractile (the phase I rapid contraction and vasodilation; the phase II sustained contraction) response in both the second and the third branch pulmonary artery rings compared with the control group (P < 0.05 , P < 0.01); (2) The second and third pulmonary artery rings incubated by NFA which phase II persistent vasoconstriction were significantly attenuated compared with the H group (P < 0.05 , P < 0.01).

CONCLUSIONThe blocker of the chloride channels attenuates the second and third branch pulmonary artery rings constriction in rat, especially the phase II persistent vasoconstriction, so then have an antagonistic effect on HHPV.

Animals ; Chloride Channels ; antagonists & inhibitors ; Hypercapnia ; physiopathology ; Hypoxia ; physiopathology ; Niflumic Acid ; pharmacology ; Pulmonary Artery ; physiopathology ; Pulmonary Circulation ; Rats ; Vasoconstriction ; drug effects

Diabetic rats were induced by intraperitoneal injection of streptozotocin.TUNEL and immunohistochemistry results showed that the renal tubular cell apoptosis index(AI)and Bax protein expression were significantly reduced,and the Bcl-2 protein expression in glomeruli was significantly increased in diabetic rats with stable hyperglycemia treated by benazepril compared with diabetic rats with stable hyperglycemia treated by vehicle(all P

AIMTo investigate the role of oxygen free radicals (OFR) in hepatic ischemia and reperfusion injury (HI/RI) and effect of propofol on them.

METHODSThe rabbits were randomly divided into three groups (n=10), sham operated group (Control), HIR group(I/R) and HIR + propofol group (PRO). Changes of several parameters which included malondialdehyde (MDA), superoxide dismutase (SOD), xanthine oxidase (XO) and alanine aminotransferase(ALT) were measured before ischemia, 45 minutes after ischemia and 45 minutes after reperfusion in plasma. Meanwhile MDA concentration, SOD, XO activities and ALT value in liver tissue were measured, and the ultrastructure changes in liver tissue were observed under electron microscope at 45 minutes after reperfusion.

RESULTSAs compared with group control, XO, MDA and ALT increased and SOD decreased during HI/RI (P < 0.05 and P < 0.01) in plasma, and XO, MDA increased as well as SOD decreased at 45 minutes after reperfusion (P < 0.05 and P < 0.01) in liver tissue and there were abnormal changes of the hepatic ultrastructure at 45 minutes after reperfusion. Propofol reversed the results of mentioned indices as above markedly (P < 0.05 and P < 0.01).

CONCLUSIONOFR is an important factor during HI/RI, propofol may attenuate hepatic ischemia-reperfusion injury by dropping OFR level (raising SOD activity and dropping XO activity) and antagonizing lipid pe-reoxidation (reducing MDA content).

Alanine Transaminase ; metabolism ; Animals ; Free Radical Scavengers ; metabolism ; Liver ; blood supply ; ultrastructure ; Malondialdehyde ; metabolism ; Oxidation-Reduction ; drug effects ; Propofol ; pharmacology ; therapeutic use ; Rabbits ; Reactive Oxygen Species ; metabolism ; Reperfusion Injury ; drug therapy ; metabolism ; Superoxide Dismutase ; metabolism ; Xanthine Oxidase ; metabolism

OBJECTIVETo investigate the effect of siRNA silencing the role of C-Jun N-terminal Kinase (JNK) gene in excessive endoplasmic reticulum stress on lung ischemia/reperfusion injury.

METHODSMouse model of pulmonary ischemia reperfusion injury (PIRI) in situ was established with unilateral lung in vivo. Seventy experimental mice were randomly allocated into seven groups (n = 10): Sham group (Sham group), ischemia reperfusion group (I/R), PBS+ Lipofectamine2000TM transfection reagent group (I/R + PBS+ Lipo group), negative control group (I/R+ SCR group), JNK-siRNA group (I/R + siRNA(JNK1), siRNA(JNK2), siRNA(JNK3)). Mice were euthanized after experimental time out, and left lung tissue was extracted. Wet/dry lung weight ratio (W/D) and total lung water content (TLW) were tested. Light microscope, alveolar damage quantitative evaluation index (IQA) and electron microscope were observed. The expression levels of JNK and glucose regulatex protein(GRP78) were detected by RT-PCR and Western blot. Apoptosis of lung tissue was determined by TUNEL.

RESULTSCompared with Sham group, all indicators above of I/R + PBS + Lipo group and I/R + SCR group were significantly increased (P < 0.01), and compared with I/R group, those indicators of the three groups all had no notable difference; those indicators were not statistically different between I/R + PBS + Lipo group and I/R + SCR group, and compared to the three groups, the above indicators in JNK-siRNA group were lower (P < 0.05, P < 0.01) except that the expression levels of GRP78 was not statistically different.

CONCLUSIONI/R induces excessive ERS in lung tissue, in which JNK pathway participates in apoptosis, leading to lung tissue injury.

Animals ; Apoptosis ; Endoplasmic Reticulum Stress ; Heat-Shock Proteins ; metabolism ; JNK Mitogen-Activated Protein Kinases ; genetics ; Lung ; physiopathology ; Lung Injury ; genetics ; MAP Kinase Signaling System ; Mice ; RNA, Small Interfering ; Reperfusion Injury ; genetics

Objective To investigate the effect of L-arginine on expression of protein kinase C(PKC)mRNA during pulmonary ischemia and reperfusion injury(PIRI)in the rabbits.Methods Single lung ischemia and reperfusion animal model was used in vivo.The rabbits were randomly divided into three groups(n=9,in each),sham operated group (Sham),PIR group(I-R)and PIR+L-arginine group(L-Arg).Changes of several rariables including malondialdehyde (MDA),superoxide dismutase(SOD),malandialde hyde(MDA),nitril oxide(NO),wet to dry ratio of lung tissue weight(W/D)and index of quantitative assessment(IQA)of histolngic lung injury were recorded at 60 minutes after reperfusion in lung tissue.Meanwhile the location and expression of PKC mRNA were observed.Lung tissue was prepared for light microscopic and electron microscopic observation at 60 minutes after reperfusion.Results In comparison with group I-R,PKC mRNA strongly expressed in intima and extima of small pulmonary artery as well as thin-waU vessels (mostly small pulmonary veins).The average optical density values of PKC-?,?and?mRNA in small pulmonary veins in L-Arg group had significance(all P＜0.01);SOD increased while MDA,W/D and IQA decreased at 60 minutes after reperfusion in lung tissue(P＜0.01 and P＜0.05).A morphologically abnormal changes of the lung tissue,were lessen markedly in L-Arg group.Conclusion L-arginine possess notably protective effects on PIRI in rabbits by activating PKC-?,?and?mRNA expression in lung tissue,raising NO level,dropping oxygen free radical level and decreasing lipid peroxidation.

AIMTo explore the role of ligustrazin on dynamic changes of lipid peroxidation in hepatic ischemia/reperfusion injury (HIRI) and its mechanism.

METHODSThe HIRI model was used. Twenty rabbits were randomly divided into control group (n = 10) and ligustrazin group (n = 10). The xanthine oxidase (XO) activity, superoxide dismutase (SOD) activity,malondialdehyde (MDA) content and glutamic pyruvic transaminase (GPT) activity in plasma were observed before ischemia and at ischemia 25 min, reperfusion 25 min, reperfusion 60 min and reperfusion 120 min.

RESULTSThe XO activity, SOD activity, MDA content and GPT activity of ligustrazin group, as compared with control group, showed significant differences (P < 0.05 or P < 0.01) at total time points of reperfusion.

CONCLUSIONLigustrazin has notable anti-lipid peroxidation effect on HIRI, which is due to its inhibiting the generation of oxygen free radicals and its strengthening scavenging of oxygen free radicals.

Alanine Transaminase ; metabolism ; Animals ; Female ; Lipid Peroxidation ; drug effects ; Liver ; drug effects ; metabolism ; Male ; Malondialdehyde ; blood ; Pyrazines ; pharmacology ; Rabbits ; Reperfusion Injury ; metabolism ; Superoxide Dismutase ; metabolism ; Xanthine Oxidase ; metabolism

AIMTo explore the effect of ligustrazine injection on the expression of heme oxygenase-1 (HO-1) in rabbits with pulmonary ischemia/reperfusion injury after.

METHODSSingle lung ischemia/reperfusion injury animal model was used in vivo. Twenty rabbits were randomly divided into two groups( n = 10, in each), pulmonary ischemia/reperfusion injury (I/R) group and I/R + ligustrazine injection (LGT) group. The tissue slides were stained by immunohistochemistry (IHC) and in situ hybridization (ISH) for HO-1 to detect the expression of HO-1 in lung and to analyze the absorbance, wet to dry ratio of lung tissue weight (W/D) and the injured alveoli rate (IAR) were measured at 180 minutes after lung reperfusion. Meanwhile the lung tissue slide was prepared for electron microscopic observation at 180 minutes after reperfusion.

RESULTSHO-1 expression was upregulated in two groups in the pulmonary endothelial cells, part of pulmonary vascular smooth muscle cells, extima of vessels and epithelial cells of airway, the absorbance was 0.168 +/- 0.016 (0.148 +/- 0.013), 0.186 +/- 0.014 (0.158 +/- 0.012) respectively.The LGTI group showed higher absorbance than those of the I/R group (P < 0.01), lower W/D and IAR values than those of the I/R group (P < 0.01) significantly and lighter abnormal changes of the lung tissue in morphology than those of the I/R group.

CONCLUSIONLigustrazine injection possesses notable protective effects on I/R in rabbits by increasing the expression of HO-1 in lung.

Animals ; Disease Models, Animal ; Heme Oxygenase-1 ; metabolism ; Lung ; blood supply ; metabolism ; Pyrazines ; pharmacology ; Rabbits ; Reperfusion Injury ; metabolism

OBJECTIVETo investigate the expression profile of interleuki-1β (IL-1β) in rat myocardium at different time points during hypoxia/reoxygenation(H/R)transition.

METHODSThe isolated Langendorff perfused rat heart model was established.Forty SD rats were randomly divided into sham group (A group) and hypoxia/reoxygenation group (H/R group). The H/R group rats were subdivided into H/R 0.5 h group(B group), H/R 1 h group(C group), H/R 2 h group(D group)according to reoxygenation time. The left ventricular development pressure(LVDP), maximal rates of increase/decrease of the left ventricular pressure(±dp/dtmax) were continuously recorded. The concentration of interleukin-1β(IL-lβ) and creatine kinase-MB (CK-MB) in myocardium was measured by ELISA. The mRNA expression of IL-lβ in myocardium was determined by RT-PCR. Microstructure of myocardium was observed under light microscopy.

RESULTSThe value of LVDP and ±dp/dtmax in hypoxia/reoxygenation group rat were significantly lower than that in sham group(P < 0.05). The expression of IL-lβ and CK-MB at protein level and the expression of IL-1β at mRNA level in hypoxia /reoxygenation group were higher than that in sham group(P < 0. 05). There were significant differences of the above parameters among H/R 0.5 h, 1 h, 2 h group(P <0.05). The concentration of IL-1β and CK-MB, the mRNA expression of IL-1β were higher in H/R 2 h group than that of other groups(P < 0.05).

CONCLUSIONThe high expression of IL-Iβ in myocardium after myocardial hypoxia /reoxygenation in rats might lead to. ischemia/reperfusion injury.

Animals ; Creatine Kinase, MB Form ; metabolism ; Disease Models, Animal ; Hypoxia ; metabolism ; pathology ; Interleukin-1beta ; metabolism ; Myocardial Ischemia ; metabolism ; Myocardium ; metabolism ; pathology ; Rats ; Rats, Sprague-Dawley