New class of quaternary ammonium salts, derivatives of methyl D-glucopyranosides

Reactions of two aromatic and two aliphatic amines with methyl 6-O-p-toluenesulfonyl-alpha-D-glucopyranoside or methyl 6-O-p-toluenesulfonyl-beta-D-glucopyranoside were performed on a micro-scale. The synthesis and preparative isolation methods have been developed for quaternary N-(methyl 2,3,4-tri-O-acetyl-6-deoxy-alpha- and -beta-D-glucopyranoside-6-yl)ammonium salts derived from three amines: trimethylamine, 2-methylpyridine, and pyridine. The reaction products were examined with 1H, 13C NMR spectroscopy. N-(Methyl 2,3,4-tri-O-acetyl-6-deoxy-beta-d-glucopyranoside-6-yl)trimethylammonium tosylate was additionally analyzed with X-ray crystallography.     

Differential sympathetic outflow elicited by active muscle in rats

The present study was undertaken to test the hypothesis that activation of the muscle reflex elicits less sympathetic activation in skeletal muscle than in internal organs. In decerebrate rats, we examined renal and lumbar (mainly innervating hindlimb blood vessels) sympathetic nerve activities (RSNA and LSNA, respectively) during 1 min of 1) repetitive (1- to 4-s stimulation-to-relaxation) contraction of the triceps surae muscle, 2) repetitive tendon stretch, and 3) repetitive contraction with hindlimb circulatory occlusion. During these interventions, RSNA and LSNA responded synchronously as tension developed. The increase was greater in RSNA than in LSNA [+51 +/- 14 vs. +24 +/- 5% (P < 0.05) with contraction, +46 +/- 8 vs. +17 +/- 4% (P < 0.05) with stretch, +76 +/- 20 vs. 39 +/- 7% (P < 0.05) with contraction during occlusion] during all three interventions: repetitive contraction (n = 10, +508 +/- 48 g tension from baseline), tendon stretch (n = 12, +454 +/- 34 g), and contraction during occlusion (n = 9, +473 +/- 33 g). Additionally, hindlimb circulatory occlusion significantly enhanced RSNA and LSNA responses to contraction. These data demonstrate that RSNA responses to muscle contraction and stretch are greater than LSNA responses. We suggest that activation of the muscle afferents induces the differential sympathetic outflow that is directed toward the kidney as opposed to the limbs. This differential outflow contributes to the distribution of cardiac output observed during exercise. We further suggest that as exercise proceeds, muscle metabolites produced in contracting muscle sensitize muscle afferents and enhance sympathetic drive to limbs and renal beds.     

Motory effects of perforating peripheral cell layers ofAmoeba proteus

Summary Perforation of peripheral cell layers ofA. proteus in any place provokes immediate endoplasm efflux, what supports the view that the hydrostatic pressure is higher in the cell interior than outside. The local effusion of endoplasm results in the reversal of flow in formerly advancing pseudopodia, in agreement with the pressure gradient theories of protoplasmic streaming. Amoebae with destroyed frontal zones squeeze all their endoplasm out through the breach, what disproves the frontal contraction hypothesis of amoeboid movement, but supports the concept of a general contraction of cell cortex.Study supported by the Research Project II.1 of the Polish Academy of Science.     

Nutritional changes induce xylogenesis in callus ofHaplopappus gracilis (NUTT.) A. Gray

Xylogenesis was induced in cultures of calli ofHaplopappus gracilis (NUTT.) A. Gray by metabolic shocks brought about by changes in nutrition. Xylogenesis was observed to occur in response to three changes in callus nutrition, caused by the following modifications of Eriksson’s nutrient medium and culture conditions: i) omission of sucrose in the medium for 3 to 6 days and then transfer of the calli onto complete Eriksson’s medium; ii) replacement of sucrose by 0.36*mol l_-1 xylose for the whole culture period; iii) omission of nitrogen sources(i.e. glycine and NH₄NO₃ omission and replacement of KNO₃ with equimolar KCI) for the whole culture period. The induction of xylogenesis in response to nutritional stress inH. gracilis can be used as a suitable model system for research concerning plant cell differentiation.     

Complementary DNA structure of the high molecular weight rat insulin-like growth factor binding protein (IGF-BP3) and tissue distribution of its mRNA

Insulin-like growth factors (IGFs) found in extracellular fluids are bound to specific binding proteins. Recently a high molecular weight IGF-binding protein (IGF-BP3) has been isolated from porcine ovarian follicular fluid based on its inhibition of follicle stimulating hormone-stimulated estradiol production in rat granulosa cells. The complete primary structure of the porcine IGF-BP3 was deduced by molecular cloning. Using the porcine cDNA as a probe, we have now isolated and characterized cDNAs encoding rat IGF-BP3 from a pregnant mare serum gonadotropin-stimulated ovarian library. The predicted amino acid sequence revealed a mature polypeptide consisting of 265 amino acids with 18 cysteines and 4 potential Asn-linked glycosylation sites. Northern analysis of the IGF-BP3 mRNA in rat tissues showed a single 2.6 kb band in liver, kidney, stomach, heart, adrenal, ovary, testis, spleen, lung, small and large intestine in varying amounts, but the message is below the limit of detection in hypothalamus and brain cortex.     

Platelet‐activating factor interaction with the human erythrocyte membrane

Platelet‐activating factor (PAF) is a soluble signal messenger present in blood at nanomolar concentration. PAF has a wide spectrum of biological activities and is produced by and effective in different cell types. Owing to its important physiological role, we wanted to characterize membrane intercalation and interaction of PAF‐16 (1‐O‐hexadecyl‐2‐acetyl‐sn‐glycero‐3‐phosphocholine) by studying its capacity to induce during short‐term incubations at high concentrations cell shape alterations, phosphatidylserine exposure, and hemolysis in human erythrocytes. Our results showed that PAF‐16 at micromolar concentrations rapidly (≤1 min) induces stable but wash‐sensitive echinocytosis and hemolysis, but no substantial phosphatidylserine exposure. In conclusion, our study characterizes PAF‐16 as a highly membrane partitioning non‐permeable molecule accumulating in the outer membrane leaflet. These membrane interacting properties of PAF should, also at physiological concentrations, be important part of its nature as a membrane affector molecule. © 2009 Wiley Periodicals, Inc. J Biochem Mol Toxicol 23:345–348, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/jbt.20297     

Genetic diversity and relatedness within packs in an intensely hunted population of wolvesCanis lupus

A population of grey wolvesCanis lupus Linnaeus, 1758 inhabiting Bia?owie?a Primeval Forest (BPF) on the Polish-Belarussian border has recovered after near extermination in the 1970s. Currently, it is intensively hunted in the Belarussian part of BPF and protected in the Polish part. We used a combination of molecular analysis, radiotracking, and field observation to study genetic diversity of the population after natural recolonisation and the consequences of heavy hunting for the genetic composition and social structure of wolf packs. Both microsatellite and mtDNA analyses revealed high genetic diversity. For 29 individuals and 20 microsatellite loci, the mean expected heterozygosity was 0.733. Four mtDNA haplotypes were found. Three of them had earlier been described from Europe. Their geographic distribution suggests that wolves recolonising BPF immigrated mainly from the north-east, and less effectively from the east and south-east. We traced the composition of 6 packs for a total of 26 pack-years. Packs were family units (a breeding pair with offspring) with occasional adoption of unrelated adult males, which occurred more frequently in packs living in the Belarussian part of the BPF, due to heavy hunting and poaching. Breeding pairs were half-sibs or unrelated wolves. Pair-bonds in the breeding pair lasted from 1 to 4 years and usually broke by the death of one or both mates. Successors of breeding females were their daughters, while a successor of a breeding male could be either his son or an alien wolf. As is evident from Bia?owie?a’s wolves, high genetic diversity may result from immigration of outside individuals, which are easily recruited to a heavily exploited local population.