The (1)O2 quenching rate constants (kQ) of alpha-tocopherol (alpha-Toc) and carotenoids such as beta-carotene, astaxanthin, canthaxanthin, and lycopene in liposomes were determined in light of the localization of their active sites in membranes and the micropolarity of the membrane regions, and compared with those in ethanol solution. The activities of alpha-Toc and carotenoids in inhibiting (1)O2-dependent lipid peroxidation (reciprocal of the concentration required for 50% inhibition of lipid peroxidation: [IC50](-1)) were also measured in liposomes and ethanol solution and compared with their kQ values. The kQ and [IC50](-1) values were also compared in two photosensitizing systems containing Rose bengal (RB) and pyrenedodecanoic acid (PDA), respectively, which generate (1)O2 at different sites in membranes. The kQ values of alpha-Toc were 2.9 x 10(8) M(-1) s(-1) in ethanol solution and 1.4 x 10(7) M(-1) s(-1) (RB system) or 2.5 x 10(6) M(-1) s(-1) (PDA system) in liposomes. The relative [IC50](-1) value of alpha-Toc in liposomes was also five times higher in the RB system than in the PDA-system. In consideration of the local concentration of the OH-group of alpha-Toc in membranes, the kQ value of alpha-Toc in liposomes was recalculated as 3.3 x 10(6) M(-1) s(-1) in both the RB and PDA systems. The kQ values of all the carotenoids tested in two photosensitizing systems were almost the same. The kQ value of alpha-Toc in liposomes was 88 times less than in ethanol solution, but those of carotenoids in liposomes were 600-1200 times less than those in ethanol solution. The [IC50](-1) value of alpha-Toc in liposomes was 19 times less than that in ethanol solution, whereas those of carotenoids in liposomes were 60-170 times less those in ethanol solution. There were no great differences (less than twice) in the kQ and [IC50](-1) values of any carotenoids. The kQ values of all carotenoids were 40-80 times higher than that of alpha-Toc in ethanol solution but only six times higher that of alpha-Toc in liposomes. The [IC50](-1) values of carotenoid were also higher than that of alpha-Toc in ethanol solution than in liposomes, and these correlated well with the kQ values.

No abstract

Abstract. The stable isotopic compositions of nitrate dissolved in 49 brands of bottled drinking water collected worldwide were measured, to trace the fate of atmospheric nitrate (NO3− atm) that had been deposited into subaerial ecosystems, using the 17O anomalies (Δ17O) of nitrate as tracers. The use of bottled water enables collection of groundwater recharged at natural, background watersheds. The nitrate in groundwater had small Δ17O values ranging from −0.2‰ to +4.5‰ n = 49). The average Δ17O value and average mixing ratio of atmospheric nitrate to total nitrate in the groundwater samples were estimated to be 0.8‰ and 3.1%, respectively. These findings indicated that the majority of atmospheric nitrate had undergone biological processing before being exported from the surface ecosystem to the groundwater. Moreover, the concentrations of atmospheric nitrate were estimated to range from less than 0.1 μmol L−1 to 8.5 μmol L−1 with higher NO3−atm concentrations being obtained for those recharged in rocky, arid or elevated areas with little vegetation and lower NO3−atm concentrations being obtained for those recharged in forested areas with high levels of vegetation. Additionally, many of the NO3−atm-depleted samples were characterized by elevated δ15N values of more than +10‰. Uptake by plants and/or microbes in forested soils subsequent to deposition and the progress of denitrification within groundwater likely plays a significant role in the removal of NO3−atm.

Hemocytin, a multidomain protein from Bombyx mori L. (Lepidoptera: Bombycidae), is an ortholog of von Willebrand factor and is expected to be a major mediator of hemocyte aggregation. Antiserum was generated against hemocytin, and immune staining of hemocytes, hemolymph, and nodules was performed. Hemocytin was observed in steady-state hemocytes but not in plasma, even after bacterial injection. When hemolymph was smeared on glass slides, hemocytin-containing fibrous structures formed a cellular network mainly consisting of granulocytes and oenocytoids. Hemocytin was stained only in the granules of the granulocytes. When nodule-like aggregates formed 30 sec after bacterial injection, both granulocytes and bacterial cells were observed binding to hemocytin-containing fibrous structures. When nodule sections were stained with antiserum, hemocytin was seen in the matrix of the nodules surrounding the hemocytes. These data suggest that hemocytin plays a major role in nodule formation as a component of the sticky fibrous structure exocytosed from granulocytes.

Abstract. Temporal variations in the stable isotopic compositions of nitrate dissolved in stream water eluted from a cool-temperate forested watershed (8 ha) were measured to quantify the biogeochemical effects of clear-cutting of trees and subsequent strip-cutting of the understory vegetation, dwarf bamboo (Sasa senanensis), with special emphasis on changes in the fate of atmospheric nitrate that had been deposited onto the watershed based on 17 O values of nitrate. A significant increase in stream nitrate concentration to 15 µmol L −1 in spring of 2004 was correlated with a significant increase in the 17 O values of nitrate. Additionally, the high 17 O values of +14.3 ‰ suggest that the direct drainage of atmospheric nitrate accounted for more than 50 % of total nitrate exported from the forested watershed peaking in spring. Similar increases in both concentrations and 17 O values were also found in spring of 2005. Conversely, low 17 O values less than +1.5 ‰ were observed in other seasons, regardless of increases in stream nitrate concentration, indicating that the majority of nitrate exported from the forested watershed during seasons other than spring was remineralized nitrate: those retained in the forested ecosystem as either organic N or ammonium and then been converted to nitrate via microbial nitrification.When compared with the values prior to strip-cutting, the annual export of atmospheric nitrate and remineralized nitrate increased more than 16-fold and fourfold, respectively, in 2004, and more than 13-fold and fivefold, respectively, in 2005. The understory vegetation (Sasa) was particularly important to enhancing biological consumption of atmospheric nitrate.

No abstract

Saw palmetto extract (SPE) has been widely used for the treatment of lower urinary-tract symptoms secondary to benign prostatic hyperplasia. The mechanisms of pharmacological effects of SPE include the inhibition of 5a-reductase, antiandrogenic effects, anti-proliferative effects, and anti-inflammatory effects. Previously, we showed that SPE bound actively to a1-adrenergic, muscarinic and 1,4-dihydropyridine calcium channel (1,4-DHP) receptors in the prostate and bladder of rats, whereas its active constituents have not been fully clarified. The present investigation is aimed to identify the main active components contained in hexane and diethyl ether extracts of SPE with the use of column chromatography and preparative HPLC. Based on the binding activity with a1-adrenergic, muscarinic, and 1,4-DHP receptors, both isolated oleic and lauric acids were deduced to be active components. Authentic samples of oleic and lauric acids also exhibited similar binding activities to these receptors as the fatty acids isolated from SPE, consistent with our findings. In addition, oleic and lauric acids inhibited 5a-reductase, possibly leading to therapeutic effects against benign prostatic hyperplasia and related lower urinary-tract symptoms.

The rate constants (ks) of 1O2 scavenging for alpha-tocopherol (alpha-Toc) and beta-carotene (beta-Car) were measured in liposome membranes, and compared with those in EtOH solution. 1O2 was site-specifically generated by photoirradiation using two photosensitizers, water-soluble Rose bengal (RB) and lipid-soluble 12-(1-pyrene)-dodecanoic acid (PDA). The ks value for beta-Car in EtOH solution was 1.3 x 10(10) M-1 s-1, which was 36 times that for alpha-Toc (3.6 x 10(8) M-1 s-1), but there was no difference between their ks values in liposomes (1.8 x 10(7) M-1 s-1 for beta-Car and 1.2 x 10(7) M-1 s-1 for alpha-Toc). In the liposomes, the ks value for alpha-Toc was affected by the membrane site where 1O2 was generated, which depended on the localization of the photosensitizer, being high at the membrane surface in the RB-system and low in the inner region of the membrane in the PDA-system. In contrast, the ks value for beta-Car was not affected by the 1O2-generating site. These differences were supposed to be caused by differences in the relative concentrations of 1O2 and active sites of alpha-Toc and beta-Car in the membranes. alpha-Toc and beta-Car inhibited 1O2-dependent peroxidation of egg yolk phosphatidylcholine (egg PC). The concentrations of alpha-Toc required for 50% inhibition of lipid peroxidation (IC50) were higher than those of beta-Car, being more than 6 times higher in EtOH solution and less than 2 times higher in liposomes. The ratio of the antioxidant activity of beta-Car to that of alpha-Toc was more in EtOH solution than in liposomes, and was well correlated with the ratio of their 1O2 scavenging rate constants.