AIM: To investigate the activity and distribution of calcineurin (CaN) in different tissues of rat. METHODS: Using western blot and immunohistochemical staining methods to measure the amount and location of CnA?, isoform of catalytic subunit of CaN in different tissues of rat. CaN activity was measured by labelled substrate peptide. RESULTS: 1. Western blot showed that CnA? expression was detected in brain, heart, skeletal muscle and lung tissues. There was no detectable CnA? expression in kidney and aorta. 2. In immunohistochemical staining study, there was strong immunostaining of CnA? in brain. CnA? was located in cytoplasm of cardiac cell, macrophage and connective tissue of peribronchiolar in lung tissue, aorta adventitia, connective tissue around small vessels and outer wall of renal tube. 3. CaN activity was highest in brain, the following was skeletal muscle, myocardium and lung tissue. CaN activity was lowest in aorta and kidney tissue. CONCLUSION: CaN is widely distributed in rats and might be involved in functional regulation of various organs and tissues.

AIM: Metallothioneins (MTs) are cysteine-rich metal-binding proteins that exert cytoprotection during metal exposure and oxidative stress. The present study was designed to investigate whether MT can directly protect NTPase on nuclear envelope from damage induced by hydroxyl radical.METHODS: Isolated hepatic nuclei from rat liver were exposed to Fe 2+ /H 2O 2 with or without MT, and the NTPase activity on nuclei was assayed using ATP and GTP as substrate, respectively. RESULTS: Incubation of rat hepatic nuclei with the Fe 2+ /H 2O 2 (in ?mol?L -1 / ?mol?L -1 : 0 1/0 5, 0 5/2 5, 1/5, 5/25) resulted in a concentration-dependent decrease in nuclear NTPase activities ( P0 05 ). In addition, incubation of hepatic nuclei with only MT had no effect on nuclear NTPase activity. CONCLUSION: These data demonstrate that hydroxyl radical generated from Fe 2+ /H 2O 2 might attack nuclear NTPase. MT antagonistically reduces toxicity of Fe 2+ /H 2O 2 system to the NTPase.

AIM: To study alterations of nitric oxide synthase (NOS) in cardiac sarcop lasmic reticulum from rats with myocardial calcification, and to explore the mec hanism of inhibition of SR function in the rats with myocardial calcification. METHODS: The myocardial calcification rat models were prepared by vit amin D3 plus nicotine for 2 weeks and 6 weeks. Cardiac SR was separated by centrifugating. T he nitric oxide (NO) production, NOS activity and NOS protein expression in the SR were perfor med. RESULTS: Compared with control, myocardial calcium content in t he 6 weeks i ncreased by 408%(P

AIM: To observe whether metallothionein plays a role in cardiac protective effect of basic fibroblast growth factor on anoxic/reperfusion (A/R) injury in cultured cardiomyocytes and study the possible mechanism of cardiac protection by bFGF.METHODS: The present study made the model of myocyte A/R injury after having a 24 h incubation by bFGF(10 -10、10 -9、10 -8 mol/L) and bFGF(10 -9 mol/L)+PD 098059 respectively. We measured the levels of MT and MDA in myocytes, and the changes of LDH and protein in cultured medium. We also counted the number of viable cell in groups.RESULTS: The contents of myocardial MT were significantly increased after treatment by bFGF. The levels of MT in 10 -10 mol/L、10 -9 mol/L and 10 -8 mol/L bFGF treated groups increased 54%\, 62%\, 76% respectively, compared with the A/R group, and the number of viable cell were also greatly increased, LDH and protein leakage in cultured medium and MDA contents in myocyte were dramatically decreased in bFGF treated groups. All the protection were completely disappeared with the inhibition of MT production with PD 098059, the inhibitor of mitogen-activated protein kinase(MAPK).CONCLUSION: MT involves in the protection of bFGF in cultured cardiomyocytes. It might be related with activation of MAPKase.

AIM: To observe the effect of hydrogen sulfide (H_2S) on the rat cardiac function in vitro, to explorer the physiological regulation of endogenous H_2S on myocardial action. METHODS: H_2S concentration and production in the rat myocardial tissues were detected. The expression of CSE (a kind of key enzyme of endogenous H_2S production) mRNA in myocardial tissues was screened by RT-PCR. Langendorff apparatus was used to perfuse the rat heart in vitro. After 20 minutes of stabilization, NaHS (10~-6 -10~-3 mol/L) were added cumulatively in order to the perfusive fluid, and another group applied physiological concentration NaHS (4?10~-4 mol/L), continuously perfusion for 20 min, heart rate (HR), difference of left ventricular pressure (△LVP), left ventricular peak rate of contraction (+LV dp/dt_~max ), peak rate of relaxation (-LV dp/dt_~max ) and coronary perfusive flow (CPF) were measured at the times. Finally, glibenclamide was applied to block the K_~ATP channel of heart, to observe the effect of NaHS at physiological concentration on cardiac function. RESULTS: NaHS concentration-dependently inhibited left ventricular ?dp/dt_~max and △LVP (P

AIM: To observe whether metallothionein plays a role in cardiac protective effect of basic fibroblast growth factor on anoxic/reperfusion (A/R) injury in cultured cardiomyocytes and study the possible mechanism of cardiac protection by bFGF.METHODS: The present study made the model of myocyte A/R injury after having a 24 h incubation by bFGF( 10-10、10-9、10-s mol/L) and bFGF( 10-9 mol/L) + PD098059 respectively. We measured the levels of MT and MDA in myocytes, and the changes of LDH and protein in cultured medium. We also counted the number of viable cell in groups. RESULTS: The contents of myocardial MT were significantly increased after treatment by bFGF. The levels of MT in I0-l0 mol/L、10-9 mol/L and 10-8 mol/L bFGF treated groups increased 54 %、 62%、 76% respectively, compared with the A/R group, and the number of viable cell were also greatly increased, LDH and protein leakage in cultured medium and MDA contents in myocyte were dramatically decreased in bFGF treated groups. All the protection were completely disappeared with the inhibition of MT production with PD098059, theinhibitor of mitogen- activated protein kinase(MAPK). CONCLUSION: MT involves in the protection of bFGF in cultured cardiomyocytes. It might be related with activation of MAPKase.

Objective: To determine the role of cross-talk between calcineurin-dependent signal transduction pathway and protein kinase C (PKC), mitogen-activated protein kinase (MAPK) and protein kinase A (PKA) in airway remodeling in asthma. Methods: Male guinea pigs were sensitized with intraperitoneal injections of ovabumin (OVA), then treated with cyclosporin A (CsA,5 mg/kg), an inhibitor of calcineurin, then inhaled OVA for 2 weeks 14 days later. Activities of calcineurin, PKC, MAPK, and PKA were was analyzed by phosphorylation and dephosphorylation. In primary cultures of rat airway smooth muscle cells (ASMC), activities of calcineurin, PKC, MAPK, and cross-talk induced by urotensin Ⅱ (UⅡ), a recently identified strong mitogen, were measured. Results: (1) The activities of calcineurin, MAPK and PKC increased by 19% (P0.05). (4) CsA 10 -6 mol/L inhibited UⅡ-stimulated PKC activity by 14% (P0.05). Conclusion:The signal transduction pathways between calcineurin and other protein kinases such as PKC, MAPK and PKA have cross-talk in airway remodeling in asthma.

Objective:To analyze the relationship between plasma level of cortistatin(CST) and coronary heart disease(CHD) and the factors that influence the level of CST.Methods: Plasma levels of CST were measured using ELISA method.The clinical data and the levels of CST of 40 healthy subjects and 39 CHD patients before and 1 d after percutaneous coronary intervention(PCI) were compared.And the factors that influenced the CST level were analyzed.Results: The CST levels of CHD group before or 1 d after PCI were significantly higher than those of the control group(1.97?1.12 and 2.01?0.77 vs 1.21?0.27,P0.05);There was no correlation between CST levels and fasting blood glucose(FBG),high sensitivity C-reactive protein(hsCRP),left ventricular ejection fraction(LVEF),severity of lesions of coronary arteries or history of hypertension;The levels of triglyceride(TG) and total cholesterol(TCHOL) negatively correlated with CST levels(?=-2.594,P

AIM: To investigate the effect of basic fibroblast growth factor (bFGF) on C-type natriuretic peptide (CNP) production, release and mRNA expression. METHODS: Human endothelial cell cultured; CNP was measured by radioimmunoassay method;CNP mRNA expression was determined by RT-PCR technique. RESULTS: bFGF could augment CNP synthesis in human endothelial cells. Compared with control group,25 ng, 50 ng, 100 ng bFGF increased CNP contents in endothelial cells by 88% (P

AIM: To observe the effect of adrenomedullin(ADM)on proliferation of vascular smooth muscle cells(VSMC) induced by urotensin Ⅱ(UⅡ). METHODS: DNA synthesis of cultured rat aortic VSMC was measured by -TdR incorporation. The activities of mitogen activated protein kinase(MAPK) were determined by isotope tagged with [?- 32 P]-ATP. RESULTS: UⅡ(10 -8 mol/L) significantly increased -TdR incorporation of VSMC and MAPK activities by 38%( P0.05 ), 32%( P0.05 ), 32%( P