[Effects of Dexmedetomidine on the levels of proinflammatory mediators IL-1ßand TNF-α in pulmonary ischemia/reperfusion injury rats and the mechanisms].

OBJECTIVE: To evaluate the effects and mechanism of the Dexmedetomidine on the levels of proinflammatory mediators interleukin 1 beta (IL-1ß) and tumor necrosis factor-α(TNF-α) in ischemia/reperfusion(I/R)rats. METHODS: Fifty healthy SPF male SD rats, 250~310 g,8~12 weeks,were randomly divided into five groups(n=10):sham operation group(sham group),I/R group, dexmedetomidine group(Dex group), atipamezole group(Atip group), dexmedetomidine plus atipamezole(Dex+Atip group). The I/R model was established by clipping hilus of left lung for 30 min and then reperfusion for 2 h. Dex group, Atip group and Dex + Atip group were performed by intraperitoneal injection dexmedetomidine(20 µg/kg),atipamezole(250 µg/kg),Dexmedetomidine(20 µg/kg)+atipamezole(250 µg/kg)respectively 30 min in advance before hilus of left lung was clipped, the rest of the process was the same with I/R group. After the experiment the rats were killed and the left lung tissues to determine the lung wet/dry weight(W/D) and total lung water content(TLW); Ultra structure of lung tissues were observed under light microscope and electron microscope; IL-1ß and TNF-α levels were determined by using ELISA. RESULTS: Compared with the sham group, the W/D、TLW、IL-1ß and TNF-α in other groups were increased significantly (P<0.05). The structure damages of lung tissues observed under light microscope and electron microscope in other groups were more serious than that of sham group. Compared with I/R、Atip、Dex+Atip group, the levels of W/D、TLW,IL-1ß and TNF-α in Dex group were lower (P<0.05), the structure damages of lung tissues observed under light microscopy and electron microscope in Dex group were slighter. There was no significant difference of the above parameters among I/R、Atip、Dex+Atip group. CONCLUSIONS: Dexmedetomidine can alleviate ischemia/reperfusion injury in rat lung through lowering the level of proinflammatory mediators IL-1ß and TNF-α,the possible mechanism may be through stimulation of α2 adrenaline receptors.

[Effects of xuebijing injection on cardiac function and structure in rats with myocardial hypoxia/reoxygenation injury].

OBJECTIVE: To investigate the protective effects of xuebijing (XBJ, Traditional Chinese Medicine Complex) injection on cardiac function in rats with myocardial hypoxia/reoxygenation(H/R) injury. METHODS: The isolated langendorff perfused rat heart model was established. One hundred and thirty SD rats were randomly divided into sham group, hypoxia/reoxygenation group, low dose XBJ(XBJL) group, middle dose XBJ(XBJM) group and high dose XBJ(XBJH) group. All groups except sham group were divided into three subgroups according to reoxygenation time(0.5 h,1 h, 2 h) (n=10). In sham group, left ventricular development pressure(LVDP), maximal rates of increase/decrease of the left ventricular pressure(±dp/dtmax), left ventricular pressure (LVP), and heart rates (HR) were recorded after 20 minutes balance perfusion. The creatine kinase-MB (CK-MB) in myocardium was detected by ELISA. In other groups, after 20 minutes balance perfusion, we perfused ThomasⅡto stop the hearts from beating for 30 minutes, then reperfused the K-H until hearts recover beating. The microstructure of myocardium was observed under light microscopy. LVDP, ±dp/dtmax, LVP and HR were continuously recorded in other four groups and the concentrations of CK-MB in myocardium were measured by ELISA at different time points after reoxygenation. Microstructure of myocardium in each group were observed under light microscopy. RESULTS: LVDP, ±dp/dtmax, LVP and HR of other groups were significantly lower than those of sham group(P<0.05). The levels of CK-MB were higher than that of sham group(P<0.05). LVDP, ±dp/dtmax, LVP and HR of XBJL, XBJM and XBJH groups were higher than those of I/R group at corresponding time points after reoxygenation(P<0.05). The levels of CK-MB were lower than that of I/R group(P<0.05) and the cardiac function was improved. The middle dose of XBJ had the best protective effect. CONCLUSIONS: Xuebijing injection can effectively improve cardiac function and structure in rats with myocardial hypoxia/reoxygenation injury, and middle dose of XBJ is the best.

[Dexmedetomidine prevents inflammatory responses in injured rat lung tissues induced by ischemia/reperfusion through inhibition of TLR4 expression].

OBJECTIVE: To investigate the effect of Dexmedetomidine (Dex) on Toll-like receptor 4(TLR4) expression in lung during lung ischemia/reperfusion(I/R) in rats and its possible protecting mechanisms. METHODS: In vivo I/R model in left lung of SD rats was estab-lished. Fifty adult healthy male SD rats were randomly divided into five groups (n=10):control group (Sham group), I/R group, Dex group, atipamezole group (Atip group) and Dex+Atip group. After the I/R experiment,rats were killed and the left lung tissues were harvest-ed to get the lung wet/dry weight(W/D); Ultrastructure of lung tissue were observed under light microscopy; The mRNA expression of TLR4 in lung tissues were determined by RT-PCR; The protein level of TLR4 in lung tissues was detected by Western blot. RESULTS: ①Compared with those in the Sham group, W/D and total lung water content (TLW) in other groups increased significantly (P<0.05), the mRNA and protein expression levels of TLR4 in lung tissues increased too. The structure damages of lung tissues observed under light microscopy in other groups were more than that of Sham group. ②Compared with those in the I/R group, W/D and TLW in the Dex group were lower (P<0.05, P<0.01), the mRNA and protein expression levels of TLR4 in lung tissues decreased (P<0.01), and reduced structure damages of lung tissues were observed under light microscopy in Dex group. ③Compared with those in the Dex group, W/D and TLW in the Dex+Atip group were higher (P<0.01), the mRNA and protein expression levels of TLR4 in lung tissues increased (P<0.01), and the structure damages of lung tissues observed under light microscopy were more serious. There was no significant difference of the above parameters among I/R、Atip、Dex+Atip groups. CONCLUSIONS: Lung ischemia/reperfusion caused high expression of TLR4 and finally induced damages of the lung. Dexmedetomidine could inhibit TLR4 expression and alleviate the lung ischemia/reperfusion injury, which was related to activation of α2-adreno receptor.

[Dynamic changes of IL-1ß in rat myocardium during hypoxia/ reoxygenation transition].

OBJECTIVE: To investigate the expression profile of interleuki-1ß (IL-1ß) in rat myocardium at different time points during hypoxia/reoxygenation(H/R)transition. METHODS: The 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-1ß(IL-lß) and creatine kinase-MB (CK-MB) in myocardium was measured by ELISA. The mRNA expression of IL-lß in myocardium was determined by RT-PCR. Microstructure of myocardium was observed under light microscopy. RESULTS: The 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-lß and CK-MB at protein level and the expression of IL-1ß 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-1ß and CK-MB, the mRNA expression of IL-1ß were higher in H/R 2 h group than that of other groups(P < 0.05). CONCLUSION: The high expression of IL-Iß in myocardium after myocardial hypoxia /reoxygenation in rats might lead to. ischemia/reperfusion injury.

[Ischemic postconditioning attenuates pneumocyte apoptosis after lung ischemia/reperfusion injury via inactivation of p38 MAPK].

OBJECTIVE: To investigate the role of p38 MAPK on ischemic postconditioning (IPO) attenuating pneumocyte apoptosis after lung ischemia/reperfusion injury (LIRI). METHODS: Forty adult male SD rats were randomly divided into 5 groups based upon the intervention (n = 8): control group (C), LIR group (I/R), LIR + IPO group (IPO), IPO + solution control group (D), IPO + SB203580 group (SB). Left lung tissue was isolated after the 2 hours of reperfusion, the ratio of wet lung weight to dry lung weight (W/D), and total lung water content (TLW) were measured. The histological structure of the left lung was observed under light and electron transmission microscopes, and scored by alveolar damage index of quantitative assessment (IQA). Apoptosis index (AI) of lung tissue was determined by terminal deoxynuleotidyl transferase mediated dUTP nick end and labeling (TUNEL) method. The mRNA expression and protein levels of and Bax were measured by RT-PCR and quantitative immunohistochemistry (IHC). RESULTS: Compared with C group, W/D, TLW, IQA, AI and the expression of Bax of I/R were significantly increased, the expression of Bcl-2 and Bcl-2/Bax were significantly decreased (P < 0.05, P < 0.01), and was obviously morphological abnormality in lung tissue. Compared with I/R group, all the indexes of IPO except for the expression of Bcl-2 and Bcl-2/ Bax were obviously reduced, the expression of Bcl-2 and Bcl-2/Bax were increased (P < 0.05, P < 0.01). All the indexes between D and IPO were little or not significant( P > 0.05). The expression of Bcl-2 and Bcl-2/Bax of SB were significantly increased and other indexes were reduced than those of IPO (P < 0.05, P < 0.01). CONCLUSION: IPO may attenuate pneumocyte apoptosis in LIRI by inactivation of p38 MAPK, up-regulating expression of Bcl-2/Bax ratio.

[Glybenclamide regulate ERK1/2 signal pathway during hypoxia hypercapnia pulmonary vasoconstriction in rats].

OBJECTIVE: To 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. METHODS: We 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. RESULTS: Under 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). CONCLUSION: Gly may mediate HHPV via activating ERK1/2 signal transduction pathway.

[Calcium-activated chloride channels are involved in two-phase hypoxic pulmonary vasoconstriction in rat pulmonary arteries].

The aim of the present study was to investigate the roles of calcium-activated chloride channels (Cl(Ca)) in the two-phase hypoxic pulmonary vasoconstriction (HPV). The second pulmonary artery branches were dissected from male Sprague-Dawley rats, and the changes in vascular tone were measured by using routine blood vascular perfusion in vitro. The result showed that, under normoxic conditions, Cl(Ca) inhibitors (NFA and IAA-94) significantly relaxed second pulmonary artery contracted by norepinephrine (P < 0.01), but merely had effects on KCl-induced second pulmonary artery contractions. A biphasic contraction response was induced in second pulmonary artery ring pre-contracted with norepinephrine exposed to hypoxic conditions for at least one hour, but no biphasic contraction was observed in pulmonary rings pre-contracted with KCl. NFA and IAA-94 significantly attenuated phase II sustained hypoxic contraction (P < 0.01), and also attenuated phase I vasodilation, but had little effect on phase I contraction. These results suggest that Cl(Ca) is an important component forming phase II contraction in secondary pulmonary artery, but not involved in phase I contraction.

[Effect of siRNA silencing the role of JNK gene in excessive endoplasmic reticulum stress on lung ischemia/reperfusion injury].

OBJECTIVE: To 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. METHODS: Mouse 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. RESULTS: Compared 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. CONCLUSION: I/R induces excessive ERS in lung tissue, in which JNK pathway participates in apoptosis, leading to lung tissue injury.

[Effect of Xuebijing injection on TLR4--NF-kappaB--IL-1beta pathway of myocardial hypoxia/reoxygenation in rats].

OBJECTIVE: To investigate the role of Xuebijing injection(XBJI, traditional Chinese medicine), in inhibiting TLR4--NF-kappaB--IL-1beta pathway of myocardial hypoxia/reoxygenation in rats. METHODS: Thirty six male SD rats (280 +/- 30) g were randomly divided into six groups (n = 6): normal group (N group), balanced perfusion group (BP group), model group (M group), low dose XBJI group (XBJI(L) group), middle dose XBJI group (XBJI(M) group), high dose XBJI group (XBJI(H) group). By Langendorff isolated heart perfusion device to establish the model of myocardial hypoxia/reoxygenation in rats. ELISA was used to detect the concentration of interleukin-1beta (IL-1beta); Western blot was used to detect the expression of nuclear factor kappa B p65 (NF-kappaB p65) protein and toll like receptor 4 (TLR4) protein; and RT-PCR to determine the expression of NF-kappaB p65 mRNA and TLR4 mRNA;To observe microstructure changes of hypoxia/reoxygenation myocardial by light microscopy. RESULTS: Compared with M group, the IL-1beta concentration, NF-kappaB p65 and TLR4 protein,NF-kappaB p65 and TLR4 mRNA of XBJIL group, XBJI(M) group, XBJI(H) group expression decreased in varying degrees,and decreased most obviously all in XBJI(M) group (P < 0.05, P < 0.01); Myocardical structural damage was serious in M group, and improved after treatment XBJI, the most obvious was the XBJI(M). CONCLUSION: Different dose of XBJI can inhibit TLR4--NF-kappaB--IL-1beta signal transduction pathway and reduce several inflammatory reaction after myocardial hypoxia/reoxygenation injury, the 4 ml/100 ml of XBJI is the best.

[The effect of niflumic acid in hypoxic hypercapnia pulmonary vasoconstriction].

OBJECTIVE: To investigate the effect of chloride channel blocker--niflumic acid (NFA) on the pathological process of hypoxia hypercapnia-induced pulmonary vasoconstriction in rats. METHODS: We 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). CONCLUSION: The 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.

[Effect of Xuebijing Injection on TLR4-NF-κB-TNF-α pathway of rats' myocardial anoxia/reoxygenation].

OBJECTIVE: To explore the role of Xuebijing Injection (XBJI) in inhibiting inflammatory factors associated with anoxia/reoxygenation myocardial inflammatory response of rats. METHODS: Totally 36 healthy male Sprague-Dawley rats, 280 ± 30 g were randomly divided into six groups, i.e., the normal control group (N group), the balanced perfusion group (BP group),the model group (M group),the low dose XBJI group (XBJI(L) group), the middle dose XBJI group (XBJI(M) group),and the high dose XBJI group (XBJI(H) group), 6 in each group. The myocardial anoxia/reoxygenation rat model was established by Langendorff isolated heart perfusion. The concentration of TNF-α in the myocardial tissue was detected by ELISA. The expression of nuclear factor kappa B p65 (NF-κB p65) protein and Toll like receptor 4 (TLR4) protein were detected using Western blot. The expression of NF-κB p65 mRNA and TLR4 mRNA was detected by RT-PCR. Ultrastructural changes of anoxia-reoxygenation rats' heart muscle were observed under transmission electron microscope. RESULTS: Compared with the M group,the TNF-α concentration, expression levels of NF-κB p65 protein and mRNA, TLR4 protein and mRNA decreased to various degrees in the XBJI(L) group, the XBJI(M) group, and the XBJI(H) group. The TNF-α expression level decreased most significantly in the XBJI(L), group (P < 0.01), while other indices decreased most obviously in the XBJI(M) group (P < 0.01, P < 0.05). Expression levels of NF-κB p65 and TLR4 protein were obviously lower in the XBJI(M) group than in the XBJI(L) group (P < 0.05). There was no statistical difference in other indices among the three XBJI groups (P > 0.05). Myocardial fibers were loose and broken with disappearance of transverse striation, and mitochondrial cristae was dissolved and severely damaged in the M group. The aforesaid condition was improved after treated by XBJI, with the most obvious effect obtained in the XBJI(M) group. CONCLUSIONS: Different doses of XBJI could attenuate inflammatory reactions after myocardial anoxia/reoxygenation rats' heart muscle through inhibiting TLR4-NF-κB-TNF-α signal transduction pathway. The best effect could be obtained by 4 mL/100 mL XBJI.

Deficits in early-stage face perception in excessive internet users.

Excessive Internet use is associated with a limited ability to communicate effectively socially, which depends largely on the capacity for perception of the human face. We used a passive visual detection paradigm to compare the early stages of the processing of face-related information in young excessive Internet users (EIUs) and healthy normal subjects by analyzing event-related potentials (ERPs) elicited by faces and by nonface stimuli (tables), each presented in the upright and inverted position. The P1 and N170 components of the spectrum of ERPs elicited at occipital-temporal sites by the viewing of faces were larger and peaked sooner than the same ERP components elicited by tables, and inverted faces significantly enhanced and delayed the N170 component. EIUs had a generally smaller P1 component than did normal subjects, whether elicited by faces or by tables, and the N170 effect, or difference in amplitude of the N170 component for faces versus tables, was significantly smaller in the EIUs than in normal subjects. However, the N170 inversion effect, or difference in amplitude of the N170 component elicited by upright versus inverted faces, was similar in the EIUs and normal subjects. These data indicate that EIUs have deficits in the early stage of face-perception processing but may have intact holistic/configural processing of faces. Whether some deeper processes of face perception, such as face memory and face identification, are affected in EIUs needs to be investigated further with more specific procedures.