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The involvement of nitric oxide (NO) in the branchial circulation and cardiac performance of the Antarctic hemoglobinless icefish Chionodraco hamatus was investigated using isolated and perfused head and working heart preparations. In the branchial vasculature under basal (i.e. unstimulated conditions), the nitric oxide synthase (NOS) inhibitor l-NIO (l-N5-(1-iminoethyl) ornithine, 10−5 and 10−4 M), caused a marked vasoconstriction (20%), indicating a basal nitrergic vasodilator tone, while the dose–response curve of the NO donor SIN-1 (3-morpholinosydnonimine) showed a dose-dependent vasodilator effect. Acetylcholine induced a dose-dependent branchial vasoconstriction mediated by muscarinic receptors, since the effects were abolished by pre-treatment with atropine (10−4 M). Serotonin (5-HT) induced a dose-dependent branchial methysergide-sensitive vasoconstriction which was abolished by pre-treatment with l-NIO, indicating a NO-dependent mechanism. On the isolated heart, the NOS inhibitor l-NMMA (NG-monomethyl-l-arginine) 10−4 M produced a small, but significant decrease of heart rate and, as a consequence, a decrease of power output, while the NO donor sodium nitroprusside (SNP) 10−4 M elicited increases of stroke volume, stroke work and power output, suggesting an exogenous NO-dependent positive inotropism. Exposure of the bulbus arteriosus to l-NMMA was without any appreciable effect. In contrast, SNP produced a notable relaxation of the bulbus wall with a marked increase of its stiffness, as indicated by the increase of systolic and diastolic dP/dt max (23 and 104%, respectively). [Copyright &y& Elsevier]

Abstract: Physiological and health related responses to dietary inclusion of genetically modified (GM) full-fat soybean meal (Roundup Ready®; GM-soy) and maize (MON810® Bt-maize; GM-maize), as well as non-parental, untransformed lines (nGM-soy and nGM-maize D2), were evaluated in farmed Atlantic salmon (Salmo salar L.) parr during the first 8 months of feeding. Significant effects of dietary GM presence were only found in intestinal Na+-dependent d-glucose uptake and SGLT1 protein level in the region pyloric caeca in which the highest values were found in the GM-soy, intermediate in the nGM-soy, and lowest in the standard FM fed groups. Data from this study confirm that GM soybeans (RRS®) and maize (MON810®) at inclusion levels of about 6% appear to be as safe as commercially available nGM soy and maize in diets for Atlantic salmon parr. Results from studies with higher inclusion levels and with non-modified, isogenic or near-isogenic parental lines as control groups are pending. [Copyright &y& Elsevier]

Abstract: Covalent immobilization of glutamate dehydrogenase (GDH) onto activated Si/SiO2 supports was analyzed by both atomic force microscopy (AFM) and an enzymatic assay. When the concentration of 3-aminopropyltriethoxysilane used in the first derivatization step of the silicon surface was decreased, the specific enzymatic activity also decreased, whereas the mean roughness increased. Thus, the activity of immobilized GDH is critically dependent on the conditions for surface derivatization, and is inversely correlated with surface roughness. [Copyright &y& Elsevier]