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A novel electroneutral sodium-proton antiporter has been isolated from the brush border of cells from the hepatopancreas of the Kuruma prawn, Penaeus japonicus. The antiporter is different from the potential-generating two sodium-one proton antiporter found in the hepatopancreas of many invertebrates. The Penaeus sodium-proton antiporter was found to be similar to the antiporter found among vertebrates and the basolateral cell membranes of crustacean hepatopancreas.

Cryopreservation induces injuries to fish spermatozoa that in turn affect sperm quality in terms of fertilization ability, motility, DNA and protein integrity and larval survival. To reduce the loss of sperm quality due to freezing-thawing, it is necessary to improve these procedures. In the present study we investigated the ability of two antifreeze proteins (AFPI and AFPIII) to reduce the loss of quality of sea bream spermatozoa due to cryopreservation. To do so, we compared viability, motility, straight-line velocity and curvilinear velocity of fresh and (AFPs)-cryopreserved spermatozoa. AFPIII addition to cryopreservation medium improved viability, motility and straight-line velocity with respect to DMSO or DMSO plus AFPI. To clarify the molecular mechanism(s) underlying these findings, the protein profile of two different cryopreserved sperm domains, flagella and head plasma membranes, was analysed. The protein profiles differed between fresh and frozen-thawed semen and results of the image analysis demonstrated that, after cryopreservation, out of 270 proteins 12 were decreased and 7 were increased in isolated flagella, and out of 150 proteins 6 showed a significant decrease and 4 showed a significant increase in head membranes. Mass spectrometry analysis identified 6 proteins (4 from isolated flagella and 2 present both in flagella and head plasma membranes) within the protein spots affected by the freezing-thawing procedure. 3 out of 4 proteins from isolated flagella were involved in the sperm bioenergetic system. Our results indicate that the ability of AFPIII to protect sea bream sperm quality can be, at least in part, ascribed to reducing changes in the sperm protein profile occurring during the freezing-thawing procedure. Our results clearly demonstrated that AFPIII addition to cryopreservation medium improved the protection against freezing respect to DMSO or DMSO plus AFPI. In addition we propose specific proteins of spermatozoa as markers related to the procedures of fish sperm cryopreservation. [ABSTRACT FROM AUTHOR]

The aim of this work is to investigate olive oil by-product [vegetation water (VW)] inclusion in rainbow trout diet and its effect on the productive traits and the quality of the product. Two levels of VW inclusion were used and one control group was included. Fish diets were isonitrogeonous (crude protein 40%) and isoenergetic (18 MJ kg−1 DM). Two thousand and four hundred rainbow trout were used. An in vivo digestibility experiment was performed in order to determine diets' digestibility. All the fish diets and fillets were analysed to determine the proximate and fatty acid composition. On final fish fillet, lipid oxidation was determined at 0, 24, 48, 72, 96 and 192 h of storage using the 2-thiobarbituric acid method (thiobarbituric acid reactive substances). Aroma analyses on the final cooked and raw fillet were performed using an electronic nose. The VW inclusion partially reduced protein digestibility. The fish growth varied between 1.08% and 1.1% day. The supplemental level of VW led to a better antioxidant status of fish fillet, in particular, in the fillet sample after 72 h of fillet conservation. Principal component analysis in raw and cooked fish fillet indicates that the VW inclusion in the fish diet led to aroma modification on fish fillet. [ABSTRACT FROM AUTHOR]

Background/Aims: In thyroid cells, the intracellular pH plays a key role in the control of the iodide uptake, since iodide accumulation is associated with an intracellular acidification. In the present paper we studied the kinetic proprieties of the Na+/H+ antiporter (NHE) and the molecular expression of different NHE isoforms in rat thyroid PC-Cl3 cells. In addition the intracellular buffer capacity was also evaluated. Methods: pHi was measured using the pH sensitive fluorescent dye BCECF-AM. Amiloride, 5-(N,NDimethyl) hydrochloride was used to inhibit NHE activity. RT-PCR and western blot analyses were used to study the expression of NHE mRNA and protein isoforms. Results: PC-Cl3 cells shown a resting pHi, in the absence of CO2/HCO3 -, of 6.94 ± 0.1; after an acid load PC-Cl3 cells recovered toward resting pHi value, using a Na-dependent H+ extrusion mechanisms which was amiloride sensitive (Ki = 23 μM). The kinetic parameters were K(Na)app = 10 ± 2 mM and Vmax = 0.23 ± 0.02 ΔpH/min x 105 cells. NHE1, NHE2 and NHE3 were expressed at the mRNA level as well as at the protein level. Conclusion: PC-Cl3 cells express a functional Na/H exchange activity and different isoforms (NHE1, NHE2 and NHE3) are expressed in the plasma membrane. [ABSTRACT FROM AUTHOR]

Honey is a natural sweet substance produced by honeybees from the nectar of flowers, plant secretions or plant-sucking insect excretions. Sugars and water constitute the major components, other minor components characterize the organoleptic and nutritional properties. To date, Salento (Apulia region, Italy) honey production is considerably threatened due to the suggested use of neonicotinoids in order to control the insect-vectored bacterium Xylella fastidiosa (subsp. pauca). Metabolomics based on Nuclear Magnetic Resonance (NMR) spectroscopy was used to describe, for the first time, the composition of honey samples from different Salento producers. Exploratory Principal Component Analysis (PCA) showed, among the observed clustering, a separation between light and dark honeys and a discrimination according to producers, both further analyzed by supervised multivariate analysis. According to the obtained data, although limited to small-scale emerging production, Salento honey shows at the molecular level, a range of specific characteristic features analogous to those exhibited by similar products originating elsewhere and appreciated by consumers. The impact on this production should therefore be carefully considered when suggesting extensive use of pesticides in the area. [ABSTRACT FROM AUTHOR]

Abstract: The aims of the present study were (a) to compare sperm quality (percentage of motile spermatozoa, motility duration, density and fertility after cryopreservation) between precocious and normally maturing male European sea bass Dicentrarchus labrax, (b) to examine the potential of human chorionic gonadotropin (hCG) to increase spermiation in precocious males and (c) to examine the potential of hCG to induce spermatogenesis and spermiation in non-precocious 1-year-old males. One hundred precocious and 100 non-precocious fish were each randomly divided in two groups each: control (precocious saline-treated and non precocious saline-treated) and treated (precocious hCG-treated and non precocious hCG-treated). Treated groups were administered weekly with 1000 IU hCG kg−1 body weight while control groups were injected with physiological solution. Milt volume produced, sperm concentration, motility duration and fertilising ability were assessed every week in each group. The effect of the hormonal treatment on gonadal development was examined based on the gonadosomatic index and testicular histology. The results demonstrate that sperm produced by precocious fish has characteristics (mean value of motility class, mean maximum motility duration, concentration and fertility after cryopreservation) similar (P >0.05) to those produced by 2-year-old fish. Human chorionic gonadotropin treatment in precocious fish resulted in a significant increase (P <0.05) of milt volume, without affecting sperm quality. In non-precocious fish, hCG treatment resulted in greater percentage of spermiation (P <0.05) compared to non-precocious saline-treated group. At the end of the trial (three weeks), 29 out of 50 non-precocious hCG-treated fish were spermiating and, within these 23 produced >200 μl per fish of milt. No differences were observed in terms of sperm concentration, motility class, motility duration and fertilizing capacity due to hCG treatment in either precocious, or non-precocious fish. In addition, analysis of the testicular histology of fish that did not spermiate after hCG treatment, shows a significant (P <0.05) enhancement of testicular development stages. The present study demonstrated that (a) precocious European sea bass males produce milt of comparable sperm characteristics to adult individuals, (b) treatment of non-precocious males with hCG induced spermatogenesis and spermiation and (c) treatment of precocious males with hCG enhanced milt volume without affecting other sperm characteristics, including fertilizing ability. [Copyright &y& Elsevier]

The long-term goal of this research project is to set up efficient protocol that can be used to develop a standardized approach for vitrification of marine fish spermatozoa. In particular, the aim of the present study was to develop a vitrification protocol for sea bream ( Sparus aurata ) spermatozoa. To draw up the protocol, we tested two different dilution media (1% NaCl and Mounib medium), three different vitrification devices (loops, drops and cut straws), different cryoprotectants (CPs) and three different equilibration times (30, 60 and 120 s). The effect of the different vitrification procedures on spermatozoa quality was checked by measuring spermatozoa motility rate and viability, mitochondrial membrane potential and the fertilizing ability of both fresh and post-thawed gametes. The best result was obtained by dropping directly into liquid nitrogen 20 μl of spermatozoa suspension (drop-wise method) diluted with Mounib buffer containing 10% Me 2 SO + 10% glycerol. The addition of a mixture of anti-freezing proteins, AFPI and AFPIII, to Mounib buffer significantly increases the spermatozoa quality following vitrification so confirming the usefulness of AFPs in improving the quality of gametes subjected to the vitrification process. The present study proves that vitrification offers an alternative to conventional sperm cryopreservation also in this species. [ABSTRACT FROM AUTHOR]