RP-HPLC法测定胃安片中盐酸小檗碱的含量

目的：建立测定胃安片中盐酸小檗碱含量测定方法。方法色谱柱：C18柱（4．6 mm ×250 mm,5μm）;流动相：以乙腈—0．1％磷酸溶液（50∶50）（按1 g·L－1的量加入十二烷基磺酸钠）;检测波长为265 nm;流速：0．8 mL·min－1。结果盐酸小檗碱在0．25～3．00μg范围内与峰面积有很好的线性关系（r＝0．9999）,平均加样回收率为98．65％（RSD＝0．89％,n＝6）。结论该法操作简便,结果准确,可用于胃安片中盐酸小檗碱含量测定。     

Nutritional and nutraceutical characteristics of Sageretia theezans fruit

The fruit of Sageretia theezans is one of many underutilized edible fruits that grow along the southern seashores of East Asia. In this study, to evaluate the nutritional and nutraceutical values of S. theezans fruit, the composition of minerals, organic acids, and proximate and fatty acids, the total phenolic, total flavonoid, and total anthocyanin content, and the antioxidant and antidiabetic activities of S. theezans fruit were analyzed. The results indicate that S. theezans fruit could be classified as a potential potassium-, malic acid-, and linoleic/oleic acid-rich fruit. In addition, The ethyl acetate (EtOAc) fraction of the 70% ethanol (EtOH) crude extract exhibited strong antioxidant activities including free radical scavenging and reducing power activities compared with the same concentration of butylated hydroxytoluene. Furthermore, the EtOAc fraction showed significant inhibition of α-glucosidase activity. The analysis of the total phenolic and flavonoid content suggested that the remarkable antioxidant and antidiabetic activities of the EtOAc fraction are due to the presence of high levels of polyphenolic compounds.     

Functional Connections of the Vestibulo-spino-adrenal Axis in the Control of Blood Pressure Via the Vestibulosympathetic Reflex in Conscious Rats

Significant evidence supports the role of the vestibular system in the regulation of blood pressure during postural movements. In the present study, the role of the vestibulo-spino-adrenal (VSA) axis in the modulation of blood pressure via the vestibulosympathetic reflex was clarified by immunohistochemical and enzyme immunoassay methods in conscious rats with sinoaortic denervation. Expression of c-Fos protein in the intermediolateral cell column of the middle thoracic spinal regions and blood epinephrine levels were investigated, following microinjection of glutamate receptor agonists or antagonists into the medial vestibular nucleus (MVN) and/or sodium nitroprusside (SNP)-induced hypotension. Both microinjection of glutamate receptor agonists (NMDA and AMPA) into the MVN or rostral ventrolateral medullary nucleus (RVLM) and SNP-induced hypotension led to increased number of c-Fos positive neurons in the intermediolateral cell column of the middle thoracic spinal regions and increased blood epinephrine levels. Pretreatment with microinjection of glutamate receptor antagonists (MK-801 and CNQX) into the MVN or RVLM prevented the increased number of c-Fos positive neurons resulting from SNP-induced hypotension, and reversed the increased blood epinephrine levels. These results indicate that the VSA axis may be a key component of the pathway used by the vestibulosympathetic reflex to maintain blood pressure during postural movements.     

Myeloid-specific SIRT1 Deletion Aggravates Hepatic Inflammation and Steatosis in High-fat Diet-fed Mice

Sirtuin 1 (SIRT1) is a mammalian NAD⁺-dependent protein deacetylase that regulates cellular metabolism and inflammatory response. The organ-specific deletion of SIRT1 induces local inflammation and insulin resistance in dietary and genetic obesity. Macrophage-mediated inflammation contributes to insulin resistance and metabolic syndrome, however, the macrophage-specific SIRT1 function in the context of obesity is largely unknown. C57/BL6 wild type (WT) or myeloid-specific SIRT1 knockout (KO) mice were fed a high-fat diet (HFD) or normal diet (ND) for 12 weeks. Metabolic parameters and markers of hepatic steatosis and inflammation in liver were compared in WT and KO mice. SIRT1 deletion enhanced HFD-induced changes on body and liver weight gain, and increased glucose and insulin resistance. In liver, SIRT1 deletion increased the acetylation, and enhanced HFD-induced nuclear translocation of nuclear factor kappa B (NF-κB), hepatic inflammation and macrophage infiltration. HFD-fed KO mice showed severe hepatic steatosis by activating lipogenic pathway through sterol regulatory element-binding protein 1 (SREBP-1), and hepatic fibrogenesis, as indicated by induction of connective tissue growth factor (CTGF), alpha-smooth muscle actin (α-SMA), and collagen secretion. Myeloid-specific deletion of SIRT1 stimulates obesity-induced inflammation and increases the risk of hepatic fibrosis. Targeted induction of macrophage SIRT1 may be a good therapy for alleviating inflammation-associated metabolic syndrome.     

Characteristics of K+ Outward Currents in the Cochlear Outer Hair Cells of Circling Mice within the First Postnatal Week

K⁺ outward currents in the outer hair cells (OHCs) of circling mice (homozygous (cir/cir) mice), an animal model for human deafness (DFNB6 type), were investigated using a whole cell patch clamp technique. Littermate heterozygous (+/cir) mice of the same age (postnatal day (P) 0 -P6) were used as controls. Similar slow rising K⁺ currents were observed in both genotypes, but their biophysical and pharmacological properties were quite different. The values of V_half for activation were significantly different in the heterozygous (+/cir) and homozygous (cir/cir) mice (-8.1±2.2 mV, heterozygous (+/cir) mice (n=7) and -17.2±4.2 mV, homozygous (cir/cir) mice (n=5)). The inactivation curve was expressed by a single first order Boltzmann equation in the homozygous (cir/cir) mice, while it was expressed by a sum of two first order Boltzmann equations in the heterozygous (+/cir) mice. The K⁺ current of homozygous (cir/cir) mice was more sensitive to TEA in the 1 to 10 mM range, while the 4-AP sensitivities were not different between the two genotypes. Removal of external Ca²⁺ did not affect the K⁺ currents in either genotype, indicating that the higher sensitivity of K⁺ current to TEA in the homozygous (cir/cir) mice was not due to an early expression of Ca²⁺ activated K⁺ channels. Our results suggest that the K⁺ outward current of developing homozygous (cir/cir) mice OHCs is different in both biophysical and pharmacological aspects than that of heterozygous (+/cir) mice.     

Short-term Treatment of Daumone Improves Hepatic Inflammation in Aged Mice

Chronic inflammation has been proposed as one of the main molecular mechanisms of aging and age-related diseases. Although evidence in humans is limited, short-term calorie restriction (CR) has been shown to have anti-inflammatory effects in aged experimental animals. We reported on the long-term treatment of daumone, a synthetic pheromone secreted by Caenorhabditis elegans in an energy deficient environment, extends the life-span and attenuates liver injury in aged mice. The present study examined whether late onset short-term treatment of daumone exerts anti-inflammatory effects in the livers of aged mice. Daumone was administered orally at doses of 2 or 20 mg/kg/day for 5 weeks to 24-month-old male C57BL/6J mice. Increased liver macrophage infiltration and gene expression of proinflammatory cytokines in aged mice were significantly attenuated by daumone treatment, suggesting that short-term oral administration of daumone may have hepatoprotective effects. Daumone also dose-dependently suppressed tumor necrosis factor-α (TNF-α)-induced nuclear factor-κB (NF-κB) phosphorylation in HepG2 cells. The present data demonstrated that short-term treatment of daumone has anti-inflammatory effects in aged mouse livers possibly through suppression of NF-κB signaling and suggest that daumone may become a lead compound targeting aging and age-associated diseases.     

Extremely Low Frequency Magnetic Field Modulates the Level of Neurotransmitters

This study was aimed to observe that extremely low frequency magnetic field (ELF-MF) may be relevant to changes of major neurotransmitters in rat brain. After the exposure to ELF-MF (60 Hz, 2.0 mT) for 2 or 5 days, we measured the levels of biogenic amines and their metabolites, amino acid neurotransmitters and nitric oxide (NO) in the cortex, striatum, thalamus, cerebellum and hippocampus. The exposure of ELF-MF for 2 or 5 days produced significant differences in norepinephrine and vanillyl mandelic acid in the striatum, thalamus, cerebellum and hippocampus. Significant increases in the levels of serotonin and 5-hydroxyindoleacetic acid were also observed in the striatum, thalamus or hippocampus. ELF-MF significantly increased the concentration of dopamine in the thalamus. ELF-MF tended to increase the levels of amino acid neurotransmitters such as glutamine, glycine and γ -aminobutyric acid in the striatum and thalamus, whereas it decreased the levels in the cortex, cerebellum and hippocampus. ELF-MF significantly increased NO concentration in the striatum, thalamus and hippocampus. The present study has demonstrated that exposure to ELF-MFs may evoke the changes in the levels of biogenic amines, amino acid and NO in the brain although the extent and property vary with the brain areas. However, the mechanisms remain further to be characterized.