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A rapid and reproducible assay for the determination of neprilysin activity is reported. This method is based on fluorimetric detection of a dansylated dipeptide, 5-dimethylaminonaphthalene-1-sulfonyl- d-Ala-Gly, enzymatically formed from the substrate 5-dimethylaminonaphthalene-1-sulfonyl- d-Ala-Gly-Phe( pNO)-Gly after separation by high-performance liquid chromatography using a C-18 reversed-phase column by isocratic elution. The detection limit of this method is at a level as low as 0.2 nmol mL, it yields highly reproducible results and the time consumed for analysis is less than 6.8 min per sample for separation and quantification. By using this assay, the stimulatory effect of (+)MK-801 (dizocilpine maleate)-a noncompetitive N-methyl-[ d]-aspartate receptor antagonist-on this enzyme activity was observed in rat brain regions 3 days after the treatment. This new method would be useful for clarification of the physiological role of this enzyme. [ABSTRACT FROM AUTHOR]

Axonal transport of neprilysin, a putative neuropeptide degrading-enzyme, was examined in the proximal, middle, and distal segments of rat sciatic nerves using a double ligation technique. Neprilysin activity was significantly increased not only in the proximal segment but also in the distal segment 12-120 h after ligation, and the maximal neprilysin activity was found in the proximal and distal segments at 96 and 72 h, respectively. Western blot analysis of neprilysin showed that its immunoreactivities in the proximal and distal segments were 2.8- and 2.4-fold higher than that in the middle segment, indicating that neprilysin is transported by anterograde and retrograde axonal flow. These observations suggest that neprilysin may be involved in the metabolism of neuropeptides in nerve terminals or synaptic clefts. [ABSTRACT FROM AUTHOR]

The physiological function of interleukin-6 within the central nervous system (CNS) is complex; interleukin-6 exerts neurotrophic and neuroprotective effects and yet can also function as a mediator of inflammation, demyelination, and astrogliosis depending on the cellular context. However, the roles of interleukin-6 in astrocytes are poorly understood. In the present study, we investigated the effect of the pro-inflammatory cytokine interleukin-6 on the production of the inflammatory mediator prostaglandin E2 in mouse astrocytes. Interleukin-6 stimulated prostaglandin E2 production in a time-dependent fashion via a rapid and transient induction of cyclooxygenase-2 messneger RNA, followed by cyclooxygenase-2 protein synthesis. Interleukin-6 may act on the nervous system by interacting with its specific soluble interleukin-6 receptor and the signal transducer 130-kDa glycoprotein. Simultaneous treatment of astrocytes with interleukin-6 and soluble interleukin-6 receptor caused marked induction of prostaglandin E2 synthesis, and this effect was suppressed by adding a neutralizing antibody against soluble interleukin-6 receptor. Furthermore, the mouse 130-kDa glycoprotein antibody suppressed prostaglandin E2 formation induced by interleukin-6, as well as interleukin-6/soluble interleukin-6 receptor complexes, in a dose-dependent manner. These results indicate that interleukin-6/soluble interleukin-6 receptor complexes and the signal transducer 130-kDa glycoprotein play an important role in the regulation of cyclooxygenase-2 expression and subsequent prostaglandin E2 formation in mouse astrocytes and that interleukin-6 is an important regulator of immune and inflammatory processes in the CNS. [ABSTRACT FROM AUTHOR]

Th effect of monensin, which inhibits trans-Golgi function, on the levels of tachykinins and their processing enzyme activity was examined in organ-cultured rat dorsal root ganglia (DRG). Using an enzyme immunoassay method, we measured neurokinin A and substance P immunoreactivity in the DRG cultured for 72 h with and without 0.1 μM monensin. Both tachykinins were reduced in the DRG treated with monensin. Treatment with monensin also reduced the activity of carboxypeptidase E, which is one of the proteolytic processing enzymes of neuropeptides. These data suggest that proteolytic processing enzymes may in part modulate the biological activity of neuropeptides within a trans-Golgi apparatus. [Copyright &y& Elsevier]

BACKGROUND Expanded vermiculite is widely used in many fields, especially as an ameliorant in agriculture. Although it is known as a cation-exchanger, in a search for a new cesium adsorbent for environmental conservation, the ion-exchange behaviour of cesium on vermiculite in various grain sizes was investigated. The adsorption of cesium from artificial seawater was also investigated. RESULTS The effect of the vermiculite grain size was clearly identified. The preferred gain size for general use was found to be 500 µm. The amount of adsorption was low in these artificial seawater samples, however, almost similar ion-exchange behaviour was observed in both of the pure water and artificial seawater samples. CONCLUSION Adjustment of grain size according to the end use enables unlimited availability for application as an adsorbent of cesium. The results showed that vermiculite is a promising material for the recovery of cesium from contaminated seawater. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: We previously reported that interleukin-6 (IL-6) was locally produced in the early period after intraperitoneal (i.p.) or subcutaneous carbon tetrachloride (CCl4) administration, but not after oral (p.o.) administration. In the present study, we focused on the up-regulation of stress-inducible proteins induced by IL-6 after i.p. CCl4 administration. The expression of heme oxygenase-1 (HO-1) (EC 1.14.99.3) mRNA and protein were induced more in rats administered CCl4 via the i.p. route, compared with the p.o. route; however, expression of heat shock protein (HSP) 72 and HSP90 mRNA were increased to similar extents in both experimental groups. The induction of HO-1 mRNA and protein after i.p. CCl4 administration were significantly reduced after pretreatment with anti-rat IL-6 antibody. Activation of the signal transducer and activator of transcription factor 3 (STAT3), which promotes HO-1 expression, peaked together with plasma levels of IL-6 after i.p. CCl4 administration, suggesting that hepatic HO-1 expression was increased by IL-6 via the Janus kinase/STAT3 pathway. The present data indicate that hepatic HO-1 is up-regulated by endogenously produced IL-6, in addition to its up-regulation by heme derived from cytochrome P450 which has already been reported in rats administered i.p. CCl4. The up-regulation of hepatic HO-1 expression may reduce the tissue injury to livers caused by CCl4. [Copyright &y& Elsevier]

Abstract: IL-6 induction depending on the mode of carbon tetrachloride (CCl4) administration was investigated in rats. After the intraperitoneal (i.p.) administration of CCl4 in 50% corn oil at 1.0ml/kg body weight, IL-6 level markedly increased in plasma and peaked at 4h. TNF-α and IL-1β levels gradually increased, reaching the maximum at 24h. IL-10 level transiently peaked at 4h and then decreased, but later further increased, reaching the second peak at 24h. Plasma alanine aminotransferase (ALT) and sorbitol dehydrogenase (SDH) activities peaked at 24h. As the vehicle-to-CCl4 ratio increased, the level of IL-6 decreased and the activities of ALT and SDH increased. After oral CCl4 administration, IL-6 was not significantly detected. IL-6 level in peritoneal exudate fluid (PEF) increased simultaneously with plasma IL-6 level after i.p. CCl4 administration, but the total amount of PEF IL-6 was 37-fold as much as that of plasma IL-6, in contrast to the result that the total amount of plasma IL-6 was 19-fold as much as that of PEF IL-6 after i.p. lipopolysaccharide administration. These results suggest that i.p. administration of CCl4 dissolved in a small amount of vehicle selectively induces a high production of IL-6 in the peritoneal cavity early after the administration. Since IL-6 is a protective cytokine against hepatotoxicity, its induction should be taken into consideration during analysis of data obtained using the CCl4-induced liver injury model. [Copyright &y& Elsevier]