Dynamic changes of IL-1β in rat myocardium during hypoxia/ reoxygenation transition / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the expression profile of interleuki-1β (IL-1β) in rat myocardium at different time points during hypoxia/reoxygenation(H/R)transition.</p><p><b>METHODS</b>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-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.</p><p><b>RESULTS</b>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-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).</p><p><b>CONCLUSION</b>The high expression of IL-Iβ in myocardium after myocardial hypoxia /reoxygenation in rats might lead to. ischemia/reperfusion injury.</p>

Effect of Xuebijing Injection on TLR4-NF-κB-TNF-α pathway of rats' myocardial anoxia/reoxygenation / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To explore the role of Xuebijing Injection (XBJI) in inhibiting inflammatory factors associated with anoxia/reoxygenation myocardial inflammatory response of rats.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>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.</p>

Calcium-activated chloride channels are involved in two-phase hypoxic pulmonary vasoconstriction in rat pulmonary arteries / 生理学报

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 / 中国应用生理学杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>I/R induces excessive ERS in lung tissue, in which JNK pathway participates in apoptosis, leading to lung tissue injury.</p>

Effect of Xuebijing injection on TLR4--NF-kappaB--IL-1beta pathway of myocardial hypoxia/reoxygenation in rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSION</b>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.</p>

The effect of niflumic acid in hypoxic hypercapnia pulmonary vasoconstriction / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the effect of chloride channel blocker--niflumic acid (NFA) on the pathological process of hypoxia hypercapnia-induced pulmonary vasoconstriction in rats.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>(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).</p><p><b>CONCLUSION</b>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.</p>

Glybenclamide regulate ERK1/2 signal pathway during hypoxia hypercapnia pulmonary vasoconstriction in rats / 中国应用生理学杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSION</b>Gly may mediate HHPV via activating ERK1/2 signal transduction pathway.</p>

Ischemic postconditioning attenuates pneumocyte apoptosis after lung ischemia/reperfusion injury via inactivation of p38 MAPK / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To investigate the role of p38 MAPK on ischemic postconditioning (IPO) attenuating pneumocyte apoptosis after lung ischemia/reperfusion injury (LIRI).</p><p><b>METHODS</b>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).</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSION</b>IPO may attenuate pneumocyte apoptosis in LIRI by inactivation of p38 MAPK, up-regulating expression of Bcl-2/Bax ratio.</p>