Cardiac hypertrophy is the main cause of heart failure and sudden death in patients. But the pathogenesis is unclear. Angiotensin II may contribute to cardiac hypertrophy in response to pressure overload. In angiotensin II‐treated cardiomyocytes, there is a larger cross‐sectional area, more apoptosis cells, and a reduction of irisin expression. An increase in P62, an autophagy flux index, as well as LC3II, were observed in cardiomyocytes after angiotensin II‐induced injury. Surprisely, irisin supplementation increased LC3II expression and decreased P62 expression, consisted of results of RFP‐GFP‐LC3B adenovirus transfection, and reduced cardiomyocyte apoptosis, meanwhile, the protection of irisin was reversed by the autophagy inhibitor 3‐methyladenine. In animal experiments, overexpression of irisin reduced cardiomyocyte apoptosis and alleviated myocardial hypertrophy caused by pressure overload. The above results indicate that irisin‐induced protective autophagy and alleviated the apoptosis signaling pathway in cardiomyocytes, consequently reducing cardiomyocyte apoptosis after angiotensin II‐induced injury. Hence, increasing irisin expression may be a new way to improve cardiac function and quality of life in patients with cardiac hypertrophy.
Background and Purpose: Neuropathic pain is a major side-effect of paclitaxel (PTX) chemotherapy. Although the precise mechanisms responsible for this pain are unclear, the activation of neuroglia and upregulation of the TLR4/NF-κB pathway are known to be involved. In this study, we determined whether electroacupuncture (EA) could limit mechanical hypersensitivity resulting from the chemotherapeutic drug PTX in rats, and investigated the potential mechanisms involved. Methods: Rats intraperitoneally received a cumulative dose of 8 mg/kg PTX (2 mg/kg per day) or vehicle control on alternate days (day 0, 2, 4 and 6). EA treatment (10 Hz, 1 mA) was applied at bilateral ST36 acupoints in rats once every other day on days 0-14. For sham EA, needles were inserted at ST36 acupoints without electrical stimulation. Mechanical allodynia was measured by mechanical withdrawal latency (MWL) of paws to a mechanical stimulus every 2 days. Protein expression of TLR4 and NF-κB p65, as well as TMEM119 and GFAP (indicators of microglia and astrocytes, respectively) in spinal cord was quantified by Western blot analysis. Levels of inflammatory cytokines IL-1β and TNF-α in spinal cord and serum were detected by ELISA. Results: Mechanical allodynia induced by PTX in both paws (right and left) of rats was significantly attenuated by EA but not sham EA treatment. In addition, EA, but not sham EA, inhibited the activation of both microglia (TMEM119) and astrocytes (GFAP) in lumbar spinal cord. Moreover, Western blot analysis revealed that protein expression of TLR4 and NF-κB in spinal cord was suppressed by EA but not sham EA treatment. PTX significantly increased inflammatory cytokines in spinal cord and serum, which were ameliorated by EA treatment but not by sham EA. Conclusion: These results indicate that EA treatment attenuates PTX-induced mechanical allodynia. The putative mechanism corroborating this finding could be related to the suppression of activated microglia and astrocytes in spinal cord, as well as the inhibition of the activated TLR4/NF-κB signaling pathway by EA treatment.
BackgroundThe previous study showed that the cardiac arrhythmias induced by myocardial ischemia and reperfusion were attenuated by the pretreatment of acupuncture; however, the related mechanism is not understood. The present study was therefore designed to determine whether intracellular Ca2+ ([Ca2+]i) and connexin 43 (Cx43) are involved in the mediation of the anti-arrhythmic effect of electro-acupuncture (EA) pretreatment in the rats subjected to simulative global ischemia and reperfusion (SGIR).MethodsSGIR was made in the isolated heart by a low flow perfusion followed by a flow restoration. Four groups of animals are involved in the present study, including normal control group, SGIR group, EA group and EA plus 18 beta-glycyrrhetinic acid (EAG) group. For EA pretreatment, bilateral Neiguan acupoints (PC6) of the rats were stimulated for 30 min once a day in 3 consecutive days. Cx43 antagonist was given to the rats in EAG group 30 minutes before the EA pretreatment. The resting [Ca2+]i concentration, calcium oscillation, the contents of total Cx43 and non-phosphrylated Cx43 and arrhythmia score were compared among different groups.ResultsIn EA group, the arrhythmic score, the resting [Ca2+]i concentration and the number of [Ca2+]i oscillations were all significantly less than those in SGIR group (all P < 0.05), and interestingly, after EA pretreatment, the contents of nonphosphated Cx43 in the EA group were significantly lower than that in SGIR group respectively (P < 0.05). However, when the rats were treated with Cx43 antagonist prior to the EA pretreatment, the protection effects induced by EA pretreatment were reversed.ConclusionsThe results showed that EA pretreatment could produce anti-arrhythmic effect in the rats subjected to SGIR. The anti-arrhythmic effect of EA pretreatment may be due at least partially to the inhibition of SGIR-induced calcium overload and [Ca2+]i oscillations, reduction of non-phosphorylated Cx43 and the enhancement of the corresponding phosphorylated Cx43 in the cardiac cells.Electronic supplementary materialThe online version of this article (doi:10.1186/s12906-015-0521-y) contains supplementary material, which is available to authorized users.
In the traditional chemical vapor generation system of KBH 4 (or NaBH 4 )-Cd 21 -HCl in aqueous solution, volatile components containing cadmium species can be generated but with low efficiency. In this work, it was found for the first time that the efficiency for the generation of the cadmium-containing vapor was greatly improved when halogenate, i.e., NaBrO 3 or NaIO 3 , was added. The chemically generated vapor was separated from the reaction medium, and introduced into an atomic fluorescence spectrometer (AFS) with argon as the carrier gas, for the atomization and detection of cadmium. The experimental conditions for the efficient generation of the cadmium-containing vapor were optimized and the limit of detection (LOD, 3s) was then found to be 10 pg mL 21 . This modified chemical vapor generation system is potentially cleaner, and could have wide applications for sample introduction and/or matrix separation in analytical atomic spectrometries, such as flame atomic absorption spectrometry (FAAS), electrothermal atomic absorption spectrometry (ETAAS), inductively coupled plasma atomic emission spectrometry (ICP-AES), ICP-MS (mass spectrometry), microwave induced plasma atomic emission spectrometry (MIP-AES) and MIP-MS for the determination of ultratrace cadmium or some other elements.
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