[Studies on flavonoid constituents from herbs of Artemisia ordosica II].

Objective: To study the chemical constituents of herbs of Artemisia ordosica.

Method: The chemical constituents were isolated and repeatedly purified on silica gel column and the structures were elucidated by the NMR spectra and physicochemical properties.

Result: Eight flavones were obtained and they were identified as isosakuranetin, 7, 4'-dimethylaro madendrin, acacetin, cirsimaritin, rhamnetin, eupatolin, 5, 7, 2', 4'-tetrahydroxy-6, 5'-dimethoxyflavone, hyperoside.

[Studies on chemical constituents of Acroptilon repens].

Objective: To investigate the chemical constituents of Acroptilon repens.

Method: The ethanol extract of A. repens was isolated and purified by means of chromatography.

[Calreticulin expression increases during delayed cardioprotection induced by hypoxic preconditioning].

Both in vivo and cultured cardiomyocyte experiments were performed to investigate the alteration of expression of calreticulin (CRT) during the delayed cardioprotection induced by hypoxic preconditioning (HPC) and the intracellular signal transduction mechanisms of the alteration. (1) Wistar rats were randomly divided into three groups: sham operation group (Sham), myocardial infarction (MI) group induced by left coronary artery ligation and HPC+MI group (4-hour HPC 24 h before MI). Twenty-four hours, 14 d and 28 d after left coronary artery ligation, myocardial function, infarction size and the area at risk were measured.

[Hypoxic preconditioning induces endoplasmic reticulum stress-related cardioprotection mediated by p38 mitogen-activated protein kinase].

Calreticulin (CRT), an important Ca(2+)-binding molecular chaperone in the endoplasmic reticulum (ER), and caspase-12, a pivotal molecule mediating ER-initiated apoptosis, are involved in the ER stress (ERS). Using primary cultured neonatal cardiomyocytes, CRT and caspase-12 expression and activation during hypoxic preconditioning (HPC) and hypoxia/reoxygenation (H/R) were studied to explore the role of ERS in cardioprotection by HPC. And by using SB203580 and SP600125 [the specific inhibitors of p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK)] separately, the role of p38 MAPK in HPC-induced ERS was also detected.

[Research on physiological and pathophysiological functions of calreticulin].

Calreticulin (CRT) is an essential Ca2+-binding /storage chaperone resident protein of endoplasmic reticulum or sarcoplasmic reticulum found across a diverse range of species. The protein is involved in the regulation of intracellular Ca2+ homeostasis and endoplasmic reticulum Ca2+ storage capacity, and is also an important molecular chaperone involved in "quality control" within secretory pathways. Playing an important role in apoptosis, cell adhesion, gene expression and autoimmunity, calreticulin is involved in the genesis, development and prognosis of many diseases.

Calreticulin induces delayed cardioprotection through mitogen-activated protein kinases.

Hypoxic preconditioning (HPC) attenuates tissue injury caused by ischemia/reperfusion. The protective mechanisms of HPC involve up-regulation of the protective proteins and mitigation of cellular calcium overload. Calreticulin (CRT), a Ca(2+)-binding chaperone, plays an important role in regulating calcium homeostasis and folding of proteins.

[Adeno-associated viral gene transfer of SERCA2a improves heart function in chronic congestive heart failure rats].

Objective: To study the therapy effect of adeno-associated viral gene transfer of sarcoplasmic reticulum Ca(2+)-ATPase 2a (SERCA2a) on chronic congestive heart failure (HF) in 30 days, and the possible mechanism of the therapy effect.

Methods: The rats were divided into four groups: control group, HF group, Group HF + EGFP, and Group HF + SERCA2a. HF rats were obtained by creating descending aortic constriction.

[Studies on flavonoids from herb of Artemisia ordosica].

Objective: To study the chemical constituents of Artemisia ordosica.

Method: The chemical constituents were isolated and repeatedly purified on silica gel column and the structures were elucidated by the NMR spectra and physico-chemical properties.

Result: Eight flavonoids were obtained and identified as 5-hydroxy-7, 4'-dimethoxyflavanone, 5-hydroxy-7, 4'-dimethoxyflavone, 5, 4'-dihydroxy-7-methoxyflavone, 5, 7-dihydroxy-6, 4'-dimethoxyflavone, 5, 4'-dihydroxy-7-methoxyflavanone, 5, 3', 4'-trihydroxy-7-methoxyflavanone, 5, 7-dihydroxy-3', 4'-dimethoxyflavone and 5, 3', 4'-trihydroxy-7-methoxyflavone.

Role of myofibrillogenesis regulator-1 in myocardial hypertrophy.

Myofibrillogenesis regulator-1 (MR-1) is a novel homologous gene, identified from a human skeletal muscle cDNA library, that interacts with contractile proteins and exists in human myocardial myofibrils. The present study investigated MR-1 protein expression in hypertrophied myocardium and MR-1 involvement in cardiac hypertrophy. Cardiac hypertrophy was induced by abdominal aortic stenosis (AAS) in Sprague-Dawley rats.

[Studies on chemical constituents in herb of Chondrilla piptocoma].

Objective: To study the chemical constituents of Chondrilla piptocoma.

Method: The chemical constituents were isolated and repeatedly purified on silica gel column and the structures were elucidated by the NMR spectra and physico-chemical properties.

Result: Seven compounds were obtained and they are identified as luteolin, 5,7,4'-trihydroxy-3'-methoxy flavone, luteolin-7-O-beta-D-glucoside, apigenin, beta-sitosterol, stigmasterol, ursolic acid.

[Studies on chemical constituents from Elsholtzia bodinieri Vaniot].

Objective: To study the chemical constituents from Elsholtza bodinieri Vaniot.

Method: The chemical constituents were isolated and repeatedly purified on silica gel column and the structures were elucidated by the NMR spectra and physico-chemical properties.

Results: Seven compounds were obtained and they are identified as 5,7-dihydroxyflavone, 5,7,3',4-tetrahydroxyflavone, 5,3',4'-trihydroxy-7-O-beta-D-glucoside, acacetin, oleanolic acid, beta-sitosterol, daucosterol.

[Role of hypoxia-inducible factor-1alpha in the prevention of cardiomyocyte injury induced by hypoxic preconditioning].

In order to understand the intracellular mechanism of preconditioning, we investigated the relationship among activities of extracellular signal-regulated protein kinases (ERKs), the expression of hypoxia-inducible factor -1alpha (HIF-1alpha) and the effect of hypoxic preconditioning (HPC) on cell injury induced by hypoxia-reoxygenation in cultured neonatal rat cardiomyocytes 24 h after brief hypoxia. Cultured cardiomyocytes of neonatal Sprague-Dawley rats were divided into four groups: hypoxia/reoxygenation (H/R), hypoxia preconditioning (HPC), hypoxia preconditioning + mitogen-activated protein kinase (MAPK) inhibitor PD98059 (HPC+PD98059), and control (C). We measured the survival rate and apoptosis rate of cardiomyocytes at 6 or 12 h after hypoxia/reoxygenation, activities of extracellular signal-regulated protein kinases (ERKs), and expression of hypoxia-inducible factor-1alpha (HIF-1alpha).

Characterization of MR-1, a novel myofibrillogenesis regulator in human muscle.

The actin-myosin contractile apparatus consists of several thick filament and thin filament proteins. Specific regulatory mechanisms are involved in this highly ordered process. In this paper, we reported the identification and characterization of a novel myofibrillogenesis regulator, MR-1.

[Effects of human urotensin II on pia mater microcirculation in rats].

Aim: To investigate the effects of human urotensin II (hUII) on in vivo pia mater microcirculation in rats.

Methods: Adult SD rats were randomly assigned to the following groups: control, sodium chloride injection (NS), UII(10(-6) mol/L), noradrenaline (NA, 10(-6) mol/L), and UII (10(-6) mol/L) + NA (10(-6) mol/L) groups. For recording of microcirculation images in pia mater, skull windows were performed and mounted on the stage of an intravital microscope equipped with a TV camera.

[The coordinated effect of the excessive protein and cholesterin intake on inducing rat myocardial fibrosis and its mechanism].

Aim: To investigate the coordinated role and its mechanism of the high protein and hypercholesterol intake on inducing rat myocardial fibrosis.

Methods: The tissue level of the collagen in left ventricule, the concentrations of the plasma and the cardiac tissue angiotensin II (Ang II) and Aldosterone (Ald), the serum concentration of nitrite (NO2-), in the Wistar rats on diet which adding 20% protein or/and 100 mg/d cholesterin in the rat standard foods for 8 weeks, were measured by the colorimetric analysis of the hydroxyproline, by the radioimmunoassay, and by the assay of Griess, respectively.

Results: 1.

Protective effects of ghrelin on ischemia/reperfusion injury in the isolated rat heart.

Ghrelin, an endogenous ligand of the growth hormone secretagogue receptor, has been reported to have beneficial effects on cardiac function. The authors used the Langendorff model of ischemia/reperfusion (I/R) injury in isolated rat heart to determine whether ghrelin exerts direct cardioprotective effects. Also, the capacity of ghrelin to bind to sarcolemmal membrane fractions before and after ischemia and reperfusion was examined.

Hypoxic preconditioning of cardiomyocytes and cardioprotection: phophorylation of HIF-1alpha induced by p42/p44 mitogen-activated protein kinases is involved.

OBJECTIVE: To elucidate the molecular mechanisms involved in hypoxic preconditioning (HPC) of neonatal rat cardiomyocytes against hypoxia/reoxygenation (H/R) injury. METHODS: Cardiomyocytes from neonatal Sprague-Dawley rats were randomly distributed into the following experimental groups: (1) HPC group: 20 min of hypoxia was performed to induce hypoxic preconditioning. Twenty four hours after HPC, cardiomyocytes were exposed to lethal hypoxia for 3 h followed by 3 h normoxia (reoxygenation).

Signaling pathway of cardioprotection induced by monophosphoryl lipid A in rabbit myocardium.

OBJECTIVE: To investigate the effect of monophosphoryl lipid A (MLA) on ischemia/reperfusion (I/R) injury in rabbit heart and its signal transduction pathway. METHODS: Eighteen rabbits were randomly assigned to three groups: (1) MLA-group: Six rabbits received injection of MLA (35 &mgr;g/kg, iv) 24 h prior to 45 min of ischemia followed by 60 min of reperfusion. (2) Control group: Six rabbits received an intravenous bolus injection of the same volume of vehicle.