Effects of radiation-ecological conditions and experimental hyperthyroid states on indicators of testis and prostate androgen receptors in rats

Dose-dependent changes of the molecular characteristics on androgen receptor (AR) systems in gonads of male rats were studied at experimental L-thyroxine-induced states after low doses irradiation exposures in different reference points of 10-km Chernobyl zone. The data obtained suggest a generalized working mechanism of "oscillatorous changes" for contents, affinities and cooperative properties of AR to its natural ligands as a "mirror" reflecting some adaptational reactions in target cells that modulates their androgen-controlled biochemical activity.     

Induction of aconitate hydratase in hepatocytes of starving rats

Induction of the activity of aconitate hydratase (AH) was observed in rat hepatocytes under the conditions of food deprivation. The increase in AH activity after 4 days of starvation in the studied tissues was from 0.57 to 2.05 U/g crude liver weight. The induction of aconitase was associated both with the cytoplasmic and mitochondrial AH isoforms. The activities of cytosolic and mitochondrial AH isoforms in starving animals consisted of 83 and 17% of the total activity, respectively. The cytoplasmic and mitochondrial isoforms of the enzyme with specific activities 11.1 and 6.13 U/mg protein, respectively, were obtained by a five-step purification procedure that included fractionation with ammonium sulfate, ion-exchanging chromatography on DEAE-Toyopearl and gel filtration. The purified preparations of these AH isoforms were electrophoretically homogenous. The molecular weights of these isoforms were estimated and several kinetic and regulatory properties were studied.     

Transformation of tobacco with a gene for the thermophilic acyl-lipid desaturase enhances the chilling tolerance of plants

The desC gene for the acyl-lipid Delta9-desaturase from the thermophilic cyanobacterium Synechococcus vulcanus was introduced into Nicotiana tabacum under control of the 35S promoter. Expression of the desaturase was confirmed by Western blotting. Lipid analysis revealed that lipid content and the extent of fatty acid unsaturation significantly increased in leaves of transgenic plants. Chilling tolerance of those plants also increased, as estimated by the electrolyte leakage from the tissues damaged by cold treatments. Seeds of plants that expressed the desC gene imbibed at low temperatures demonstrated higher chilling tolerance than those of the control plants. The results demonstrate that the cyanobacterial thermophilic acyl-lipid desaturase was efficiently expressed in tobacco at ambient temperatures, and its expression resulted in the enhanced chilling tolerance of the transgenic plants.     

Glycolate oxidase isoforms are distributed between the bundle sheath and mesophyll tissues of maize leaves

Glycolate oxidase (EC 1.1.3.15) activity was detected both in the bundle sheath (79%) and mesophyll (21%) tissues of maize leaves. Three peaks of glycolate oxidase activity were separated from maize leaves by the linear KCl gradient elution from the DEAE-Toyopearl column. The first peak corresponded to the glycolate oxidase isoenzyme located in the bundle sheath cells, the second peak had a dual location and the third peak was related to the mesophyll fraction. The mesophyll isoenzyme showed higher affinity for glycolate (Km 23 micromol x L(-1)) and a higher pH optimum (7.5-7.6) as compared to the bundle sheath isoenzyme (Km 65 micromol x L(-1), pH optimum 7.3). The bundle sheath isoenzyme was strongly activated by isocitrate and by succinate while the mesophyll isoenzyme was activated by isocitrate only slightly and was inhibited by succinate. It is concluded that although the glycolate oxidase activity is mainly attributed to the bundle sheath, conversion of glycolate to glyoxylate occurs also in the mesophyll tissue of C4 plant leaves.     

GC/MS analysis of some bioactive constituents from Carthamus lanatus L

Sterols, triterpenes, volatiles, polar and other constituents in aerial parts of Carthamus lanatus were analyzed by gas chromatography-mass spectrometry. Over 90 compounds were identified most of them new for the species. Sitosterol and stigmasterol were the most abundant of 10 sterols identified in the sterol fraction. Taraxasterol, alpha- and beta-amyrine prevailed in the triterpene fraction. Volatiles, sterols and a fraction of the dichloromethane extract showed strong cytotoxicity (Artemia salina assay).     

Lipophylic compounds from Euphorbia peplis L.--a halophytic plant from the Bulgarian Black Sea coast

The chemical composition of the lipophylic fraction from the halophytic plant Euphorbia peplis L. was investigated. Compared to other terrestrial higher plants an increase of triacylglycerols and especially of glycolipids was observed. The main phospholipid was phosphatidyl choline, followed by almost equal concentrations of phosphatidyl ethanolamine and phosphatidyl glycerol. A relatively high concentration of phosphatidic acids (6.5% of the total phospholipids) was found. The main sterol appeared to be sitosterol and significant amounts of tetracyclic triterpene alcohols were found. The composition of the volatile compounds is relatively simple and only one chlorinated compound, identified as 2,2-diethoxy-1-chloroethane, was found. There was a strong toxicity of the total lipophylic extract towards Artemia salina.     

Comparative analysis of the composition of flower volatiles from Lamium L. species and Lamiastrum galeobdolon Heist. ex Fabr

The volatiles of fresh flowers from nine natural populations of four Lamium species and Lamiastrum galeobdolon were analyzed by GC/MS. 49 compounds, 43 of them new for Lamium and Lamiastrum, were identified. The studied samples showed similarity of the volatile profiles and dependence of the oil-composition on the collection site. Significant amounts of squalene were found in all samples. The presence of homological series of straight chain alkanes from C12 to C31 was shown. Phenethyl alcohol was found only in L. maculatum f. alba.     

GLUT-3 expression in human skeletal muscle

Muscle biopsy homogenates contain GLUT-3 mRNA and protein. Before these studies, it was unclear where GLUT-3 was located in muscle tissue. In situ hybridization using a midmolecule probe demonstrated GLUT-3 within all muscle fibers. Fluorescent-tagged antibody reacting with affinity-purified antibody directed at the carboxy-terminus demonstrated GLUT-3 protein in all fibers. Slow-twitch muscle fibers, identified by NADH-tetrazolium reductase staining, possessed more GLUT-3 protein than fast-twitch fibers. Electron microscopy using affinity-purified primary antibody and gold particle-tagged second antibody showed that the majority of GLUT-3 was in association with triads and transverse tubules inside the fiber. Strong GLUT-3 signals were seen in association with the few nerves that traversed muscle sections. Electron microscopic evaluation of human peripheral nerve demonstrated GLUT-3 within the axon, with many of the particles related to mitochondria. GLUT-3 protein was found in myelin but not in Schwann cells. GLUT-1 protein was not present in nerve cells, axons, myelin, or Schwann cells but was seen at the surface of the peripheral nerve in the perineurium. These studies demonstrated that GLUT-3 mRNA and protein are expressed throughout normal human skeletal muscle, but the protein is predominantly found in the triads of slow-twitch muscle fibers.     

Genotyping Yersinia pestis strains from various natural foci

Seven genetic variants of Yersinia pestis were detected by finger-printing of 85 strains of this bacterium from natural foci by means of a BX probe. Variants of Y. pestis strains correlate with certain species of carriers.