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Objective:To explore the mechanism of modified Tianwang Buxindan on oxidative damage of Trx system in parachlorophenylalanine (PCPA) insomnia model rats. Method:Sixty male SD rats were randomly divided into blank group and model group. Insomnia model was prepared through intraperitoneal injection with PCPA (150 mg·kg-1). The discontinuous injection lasted for 7 d. After successful modeling, the rats were divided into model group (the same volume of normal saline), low, medium, high-dose Tianwang Buxindan groups (8.8, 17.6, 35.2 g·kg-1·d-1) and estazolam group (0.1mg·kg-1·d-1), with 10 in each group. Autonomous activity video was used to detect circadian activity rhythm. Transmission electron microscopy (TEM) was used to observe supra chiasmatic nucleus (SCN) morphology and Organelle integrity. Enzyme-linked immunosorbent assay (ELISA) was used to detect the expressions of superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) in serum. Expressions of Trx2, TrxR2 in SCN cells were detected by immunofluorescence (IF) and Western blot. Result:Compared with blank group, the activity rhythm of model group was irregular, the activity time increased (PPPPPPPPConclusion:The effect of modified Tianwang Buxindan on insomnia model rats is related to the regulation of Trx2 and TrxR2 protein expressions in Trx system.
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Objective To investigate the role of c-Jun NH2-terminal kinase (c-JNK) signaling pathway on voltage-gated potassium channel (Kv) remodeling in left ventricular myocytes of diabetic rats,and explore the intrinsic regulatory mechanism.Methods Forty-five SD rats were randomly divided into DM group (n=25,modeling with streptozotocin induction) and control group (n=20,fed with normal diet).Transient outward potassium current (Ito) of rats' ventricular myocytes in DM group and control group was recorded by whole-cell patch-clamp method.The c-Jun activity was detected using a non-radioactive JNK kinase assay kit (Cell Signaling Technology).JNK inhibitor SP600125 was used to incubate the cardiomyocytes of diabetes rats in vitro,and then the changes of I,o in cardiomyocytes were observed.Thioredoxin reductase (TrxR) inhibitor--auranofin (AF) was used to treat the rats' cardiomyocytes incubated with SP600125,and then the changes of Ito in cardiomyocytes were observed.The content of Kv4.2 was tested using anti-Kv4.2 antibody,and the results were analyzed using a UVP bioimaging system.Results The JNK activity in DM group rose more than 1 times compared with control group,while the density of Ito decreased significantly (Control:30.2 ± 3.3pA/pF,n=16;DM:15.3 ± 2.1pA/pF,n=17;P＜0.05).The ventricular myocytes of DM rats were treated with SP600125 (10μmol/Lol/L) for 4 hours,then the Ito density increased to control group level (DM+SP600125:32.3 ± 3.7pA/pF,n=18;Control:30.2 ± 3.3pA/pF,n=16;P＜0.05).There was no significant difference in the maximum Ito density between the treated with SP600125 (Control+SP600125:31.6 ± 3.4pA/pF,n=18) and untreated control groups.The Ito density in DM myocardial cells significantly increased after treatment with the membrane permeable protein inhibitor JNKI-1 (10μmol/L),and no changes were found in control group after the same treatment.The augmentation effect of SP600125 on Ito current in DM myocytes was significantly inhibited by TrxR inhibitor auranofin (lμmol/L) (DM+SP600125+AF:15.7 ± 3.3pA/pF,n=15),while AF did not change the Ito density in control group.The expression of Kv4.2 protein was significantly increased in DM rats after administration of SP600125,which was consistent with the changes of Ito current observed in the myocardium of DM rats,although not fully restored to the level of control group myocardium.JNK inhibitor did not markedly alter the expression of Kv4.2 protein in control group myocardium.Conclusions Kv channel remodeling in DM rat's myocardium is redox-regulated,and the Ito remodeling might be assisted with the persistent activation of c-JNK signaling pathway.It has showed that c-JNK activity is significantly increased in DM rat heart and the current density of Kv channels is reduced.The inhibition of JNK signaling pathway can markedly improve Kv channel reconstruction and the process may be regulated by thioredoxin system.
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Light, besides initiating primary photochemical processes, alters the redox state of soluble components in chloroplast. The present review attempts to cover the mechanism of reductive photoactivation of enzymes of photosynthetic carbon reduction cycle using key enzymes as examples. The reduced soluble components — ferredoxin, thioredoxin and NADPH, in turn, cause the reduction of disulphides to dithiols of chloroplastic enzymes. NADP-malate dehydrogenase is subject to activation by light through changes in NADPH/NADP. The key enzyme of C4 photosynthesis-PEP carboxylase, though cytosolic, has been shown to be activated by disulphide/sulphhydryl interconversion by reductants generated in light through chloroplast electron transport flow. Pyruvate Pi dikinase activity is controlled by the adenylate energy charge. It remains unclear how light controls the activation of cytosolic enzymes.