气血并治方有效组分干预H/R损伤心肌细胞AMPK相关糖脂代谢通路的分析

目的:观察气血并治方有效组分对缺氧/复氧(H/R)损伤心肌细胞一磷酸腺苷酸活化蛋白激酶(AMPK)相关糖脂代谢通路的作用机制。方法:分离、提取、培养出生1~2 d SD乳鼠原代心肌细胞,于常规倒置相差显微镜下观察原代心肌细胞形态及生长状态,经α-横纹肌辅肌动蛋白(α-actinin)免疫荧光染色鉴定为心肌细胞后,进行缺氧3 h复氧2 h处理制作H/R损伤模型,随机分为正常组(正常氧),模型组(缺氧/复氧),曲美他嗪组(缺氧/复氧+100μmol·L-1盐酸曲美他嗪,TMZ),气血并治方有效组分组(缺氧/复氧+1 mmol·L-1气血并治方有效组分,CWQB)。采用实时荧光定量聚合酶链反应(Real-time PCR)和蛋白免疫印迹法(Western blot)测定AMPK代表性亚基心肌一磷酸腺苷酸活化蛋白激酶α(AMPKα),及其糖代谢通路中葡萄糖转运体4(GLUT4),磷酸果糖激酶2(PFK2),脂肪酸代谢通路中乙酰辅酶A羧化酶(ACC2),脂肪酸移位酶(FAT/CD36)的基因及蛋白表达情况。结果:与正常组比较,模型组,TMZ组,CWQB组的AMPKα,GLUT4,PFK2基因和蛋白表达上调,ACC2,FAT/CD36基因和蛋白表达下调(P0.05);与模型组比较,TMZ组,CWQB组AMPKα,GLUT4,PFK2,ACC2,FAT/CD36基因和蛋白表达均上调(P0.05),其中TMZ组上调AMPKα,FAT/CD36基因和蛋白,上调GLUT4,PFK2基因表达的效果更为显著(P0.05)。结论:气血并治方有效组分可以激活H/R损伤心肌细胞的AMPK信号通路,增强GLUT4介导的葡萄糖转送,PFK2参与的糖酵解,同时促进FAT/CD36调控的脂肪酸转运,上调ACC2抑制脂肪酸氧化过程,进而提高缺氧/复氧条件下心肌细胞对葡萄糖、脂肪酸等产能底物的利用能力,改善H/R损伤心肌细胞的能量代谢。     

Invertebrate muscles: thin and thick filament structure; molecular basis of contraction and its regulation, catch and asynchronous muscle

This is the second in a series of canonical reviews on invertebrate muscle. We cover here thin and thick filament structure, the molecular basis of force generation and its regulation, and two special properties of some invertebrate muscle, catch and asynchronous muscle. Invertebrate thin filaments resemble vertebrate thin filaments, although helix structure and tropomyosin arrangement show small differences. Invertebrate thick filaments, alternatively, are very different from vertebrate striated thick filaments and show great variation within invertebrates. Part of this diversity stems from variation in paramyosin content, which is greatly increased in very large diameter invertebrate thick filaments. Other of it arises from relatively small changes in filament backbone structure, which results in filaments with grossly similar myosin head placements (rotating crowns of heads every 14.5nm) but large changes in detail (distances between heads in azimuthal registration varying from three to thousands of crowns). The lever arm basis of force generation is common to both vertebrates and invertebrates, and in some invertebrates this process is understood on the near atomic level. Invertebrate actomyosin is both thin (tropomyosin:troponin) and thick (primarily via direct Ca(++) binding to myosin) filament regulated, and most invertebrate muscles are dually regulated. These mechanisms are well understood on the molecular level, but the behavioral utility of dual regulation is less so. The phosphorylation state of the thick filament associated giant protein, twitchin, has been recently shown to be the molecular basis of catch. The molecular basis of the stretch activation underlying asynchronous muscle activity, however, remains unresolved.     

Neurochemical pathways involved in the protective effects of nicotine and ethanol in preventing the development of Parkinson's disease: potential targets for the development of new therapeutic agents

In this short review, neurochemical targets are identified where nicotine, and possibly ethanol, may interact to prevent the occurrence of Parkinson's disease. These are (a) the nicotinic acetycholine receptors present in the nigrostriatal area or on the surface of microglia, (b) monoamine oxidases and (c) inducible nitric oxide synthase. If such induced changes can be verified in clinical studies, this may help in the design of new therapeutic drugs which may be of relevance to diminish the incidence and perhaps the progression of the debilitating condition of Parkinson's disease.     

Physiological effects of melatonin: role of melatonin receptors and signal transduction pathways

Melatonin, an endogenous signal of darkness, is an important component of the body's internal time-keeping system. As such it regulates major physiological processes including the sleep wake cycle, pubertal development and seasonal adaptation. In addition to its relevant antioxidant activity, melatonin exerts many of its physiological actions by interacting with membrane MT1 and MT2 receptors and intracellular proteins such as quinone reductase 2, calmodulin, calreticulin and tubulin. Here we review the current knowledge about the properties and signaling of melatonin receptors as well as their potential role in health and some diseases. Melatonin MT1 and MT2 receptors are G protein coupled receptors which are expressed in various parts of the CNS (suprachiasmatic nuclei, hippocampus, cerebellar cortex, prefrontal cortex, basal ganglia, substantia nigra, ventral tegmental area, nucleus accumbens and retinal horizontal, amacrine and ganglion cells) and in peripheral organs (blood vessels, mammary gland, gastrointestinal tract, liver, kidney and bladder, ovary, testis, prostate, skin and the immune system). Melatonin receptors mediate a plethora of intracellular effects depending on the cellular milieu. These effects comprise changes in intracellular cyclic nucleotides (cAMP, cGMP) and calcium levels, activation of certain protein kinase C subtypes, intracellular localization of steroid hormone receptors and regulation of G protein signaling proteins. There are circadian variations in melatonin receptors and responses. Alterations in melatonin receptor expression as well as changes in endogenous melatonin production have been shown in circadian rhythm sleep disorders, Alzheimer's and Parkinson's diseases, glaucoma, depressive disorder, breast and prostate cancer, hepatoma and melanoma. This paper reviews the evidence concerning melatonin receptors and signal transduction pathways in various organs. It further considers their relevance to circadian physiology and pathogenesis of certain human diseases, with a focus on the brain, the cardiovascular and immune systems, and cancer.     

BM－_（13505）抗血小板聚集作用及机理

ＢＭ－_（１３５０５）体外给药对花生四烯酸（ＡＡ）诱导的血小板聚集有明显的抑制作用，半数抑制浓度（ＩＣ_（５０））为０．１７μｍｏｌ／Ｌ；对ＡＤＰ和胶原诱导的血小板聚集无明显影响。该药显著降低家兔血小板及小鼠血浆中ＴＸＢ_２水平，对血小板ｃＡＭＰ水平无明显影响。     

咪苯嗪酮对血小板聚集、血栓形成和血小板环磷酸腺苷含量的影响

本文观察了新型强心剂咪苯嗪酮(Cl-914)对血小板聚集、血栓形成和血小板cAMP含量的影响。用比浊法测定Cl-914体外抑制AA,ADP和胶原诱导兔血小板聚集的IC_(50),分别为2.6,8.9和15.8μM;大鼠iv Cl-914 1.25mg/kg能抑制实验性血栓形成,20 mg/kg能抑制上述三种诱导剂引起的血小板聚集。在体外,用竞争性蛋白结合法测定,CI-914可使洗涤兔血小板cAMP含量明显升高。CI-914能以剂量依赖方式协同PGE_1抑制血小板聚集和升高血小板cAMP的含量。提示CI-914升高血小板cAMP含量可能是其抑制血小板聚集和抗血栓形成的主要机理。     

Static magnetic fields decrease nocturnal pineal cAMP in the rat

Magnetosensitivity of the rat's pineal cyclic adenosine monophosphate (cAMP) system was investigated. During their dark phase, rats were exposed for one hour to a static magnetic field (MF) inverting the horizontal component of the natural MF. MF-exposed animals showed a 38% decrease in pineal cAMP content (1.21 pmol/pineal gland) compared to a non-exposed control group (1.96 pmol/pineal gland).     

Pacemaker activity of locus coeruleus neurons: whole-cell recordings in brain slices show dependence on cAMP and protein kinase A

Noradrenergic neurons of the rat locus coeruleus (LC) are endogenous pacemakers that exhibit slow, tonic firing even in the complete absence of synaptic inputs. In the present study a time-dependent decline in LC spontaneous firing activity was found on intracellular dialysis during whole-cell recording with low-resistance patch electrodes; this decline was accentuated by a specific inhibitor of cAMP-dependent protein kinase (PKI5-24). Conversely, the inclusion of cAMP, 8-Br-cAMP, or the catalytic subunit of cAMP-dependent protein kinase (PKAcat) in the patch pipettes dose-dependently increased firing rate; intracellular PKI5-24 blocked both 8-Br-cAMP and PKAcat-induced firing in LC neurons. These results indicate that endogenous cAMP, via a phosphorylation-dependent route, drives tonic pacemaker activity in LC neurons.     

Beneficial effects of thiamine on recognition memory and P300 in abstinent-cocaine dependent patients

The present study evaluated the effects of thiamine vs. placebo on memory task performance and event-related electroencephalographic potentials in eight abstinent cocaine-dependent patients. Patients orally ingested 5 g of thiamine and 5 g of a lactose placebo on two separate days scheduled approximately 1 week apart. The order of administration was randomized. Double-blind procedures were followed. Approximately 3 h after ingesting the capsules, patients completed Sternberg's (1975) memory scanning task during which performance and event-related potentials (P300) were recorded simultaneously. Thiamine was found to significantly improve recognition accuracy and P300 amplitude, at the midline parietal (Pz) electrode. The improvement was most reliable under conditions of increased memory load. These preliminary findings justify a further examination of the relation between thiamine's hypothesized effects on central nervous system cholinergic function, and the direct and indirect effects of cocaine abuse. ©1997 Elsevier Science Ireland Ltd.