Impairment of mineralocorticoid receptor (MR)-dependent biological response by oxidative stress and aging: Correlation with post-translational modification of MR and decreased ADP-ribosylatable level of elongation factor 2 in kidney cells

Acute and chronic treatments of mice with the glutathione-depleting agent, L-buthionine-(SR)-sulfoximine (BSO), impaired the mineralocorticoid receptor (MR)-dependent biological response by inhibiting aldosterone binding. This steroid-binding inhibition was fully reversed when reducing agents were added to kidney cytosol obtained from mice treated for 5 h, but it was only partially reversed in cytosol obtained from mice treated for 10 days. Although the oligomeric structure of the MR-hsp90 heterocomplex was always unaffected, a decreased amount of MR protein was evidenced after the long term treatment. Such a deleterious effect was correlated with a post-translational modification of MR, as demonstrated by an increased level of receptor carbonylation. In addition, a failure at the elongation/termination step was also observed during the receptor translation process in a reticulocyte lysate system. Thus, a high polyribosomes/monomers ratio and both increased proteolysis and decreased ADP-ribosylatable concentration of elongation factor 2 (EF-2) were shown. Importantly, similar observations were also performed in vivo after depletion of glutathione. Notwithstanding the EF-2 functional disruption, not all renal proteins were equally affected as the MR. Interestingly, both EF-2 and MR expressed in old mice were similarly affected as in L-buthionine-(SR)-sulfoximine-treated young mice. We therefore propose that a dramatic depletion of glutathione in kidney cells mimics the cumulative effect of aging which, at the end, may lead to a renal mineralocorticoid dysfunction

Influence of partial replacement of fish meal and fish oil with vegetable products on the growth and muscle cellularity of juvenile shi drum, Umbrina cirrosa

Seven-month-old shi drum (Umbrina cirrosa) specimens (mean weight 18.98 g, mean length 11.80 cm) were classified into 2 groups, a control group (C) fed a standard diet and a vegetal group (V) fed a diet with partial replacement of fish meal and fish oil by vegetable products. The body and muscle parameters were studied on days 0, 27, and 62 of the experiment. On day 27, body length was similar in both groups, but body weight was significantly lower in group V than in group C. The transverse area of the white muscle was also significantly lower in V than in C. Hypertrophy was higher in C than in V, whereas hyperplasia was higher in V than in C. On day 62, the body parameters showed similar results to those found on day 27. Muscle cellularity was different from that found on day 27, since hypertrophy was higher in V than in C and hyperplasia was higher in C than in V. The feed conversion rate and specific growth rate were similar in both groups, but the daily intake rate was lower in V than in C. Therefore, it seems that the percentage of vegetables in the vegetal feed was excessively high and this caused less acceptance by the fish. The hepatosomatic, viscerosomatic, and intestinal length indices were similar in both groups. Survival was nearly 100% in both groups.Verrugatos (Umbrina cirrosa) de 7 meses (peso medio de 18.98 g, longitud media de 11.80 cm) fueron clasificados en 2 grupos: un grupo control (C), que fue alimentado con una dieta estándar, y un grupo vegetal (V), que fue alimentado con una dieta con reemplazo parcial de harina y aceite de pescado por productos vegetales. Los parámetros corporales y musculares se estudiaron en los días 0, 27 y 62 del experimento. En el día 27, la longitud corporal fue similar en ambos grupos, pero el peso fue significativamente menor en el grupo V que en el C. El área transversa del músculo blanco fue significativamente menor en V que en C. La hipertrofia fue mayor en C que en V, mientras que la hiperplasia fue mayor en V que en C. En el día 62, los parámetros corporales mostraron resultados similares a los encontrados en el día 27. La celularidad muscular fue diferente a la encontrada en el día 27, de manera que la hipertrofia fue mayor en V que en C y la hiperplasia fue mayor en C que en V. La tasa de conversión de alimento y la tasa específica de crecimiento fueron similares en ambos grupos, pero la tasa diaria de alimentación fue menor en V que en C. Así, parece ser que el porcentaje de vegetales en la dieta vegetal fue excesivamente alto y ello causó menor aceptación por los peces. Los índices hepatosomáticos, digestosómaticos e intestinales fueron similares en ambos grupos. La supervivencia fue próxima al 100% en ambos grupos.Versión del editor0,45

Lasting temperature effects on the muscle tissue, body growth and fillet texture of adult turbots, Scophthalmus maximus, L.

In the teleosts, several factors can influence the muscle growth patterns of fish by a modulation of the hypertrophy and hyperplasia. The temperature (T) is one of the most important environmental factors. Thus, the T history of fish influences on their potential growth, as it has been observed in Salmon, Salmo salar (Johnston et al., 2003) and other species. The T imprinting can influence on the muscle cellularity throughout the advanced stages of life due to the lasting T effects on myogenic cells precursors (MPC) (Steinbacher et al., 2011). In different teleost species, a correlation between texture and muscle fibre size has been demonstrated (Hatae et al., 1990). Hence, the thermal history can also influence in the flesh texture. In the present work we study the lasting T effects in adult turbots reared at different Ts during the early phases. This species reaches ≈ 1.5 kg at 18-20 months of age and the first sexual maturity takes place at ≈ 24 month

The influence of organic versus conventional feeding on the growth and survival of gilthead sea bream Sparus aurata L. juveniles

Sparus aurata specimens of 11 months of age (mean weight: 90.2 g, mean length: 18.3 cm) were classified in two diet groups: one control group was fed with conventional diet, and one experimental group was fed with an organic diet. The body and muscle parameters were studied at 0, 41 and 71 days of the experiment. The results showed the highest values of body length and weight as well as the best biological feed conversion rates in the organic group. The transverse area of white muscle, the hyperplasia and the muscle fibres density were also higher in the organic than in the conventional group (P>0.05). In contrast, hypertrophy was greater in the conventional than in the organic group (P<0.05). Survival was 100% in both groups. In conclusion, the organic feeding regime was more favourable for growth than conventional feeding.Versión del edito

Long-term Effects of the Larval Photoperiod on the Subsequent Growth of Shi Drum Umbrina cirrosa L. Specimens and the Fillet Texture at Commercial Size

Three groups of shi drum Umbrina cirrosa L. were reared with different photoperiod regimes: 24L, 12L:12D and 16L:8D (natural photoperiod) during the larval period and then all of them were transferred to a natural photoperiod. At 11.8 and 20 months of age, the body growth and the muscle parameters reached the highest values in the 24L and 12L:12D groups. The 16L:8D group showed the lowest growth. When comparing 24L with 12L:12D, the highest number of white fibres was found in the 24L group, whereas the greatest fibres size was reached in the 12L:12D group. Commercial size (28-30 cm; 290-340 g) was reached at 20 months of age in the 24L and 12L:12D groups, but at 23 months in the 16L:8D group. When comparing the three groups at the commercial stage, the larval photoperiod effect was still observed, such that the highest fibres number was again found in the 24L group, whereas the greatest fibres size was reached in the 12L:12D group. The highest values of textural hardness were observed in the 16L:8D and 24L groups. A nutritional analysis was carried out in the 16L:8D group, which showed the following percentage values: 2.66, 21.2, 74.4, and 1.46 of fat, protein, moisture and ash, respectively.0,591

Correlaciones existente entre tipos de fibras musculares, color y porcentaje de grasa intramuscular en cerdos de raza "chato murciano"

Mediante análisis de correlación se valora la influencia que los tipos de fibras I, IIA y IIX pueden tener sobre el color y el porcentaje de grasa intramuscular en el músculo longísimo lumbar del cerdo “Chato Murciano”. Los resultados demuestran que las fibras tipo IIX influyen sobre el color de la carne y que no existen correlaciones entre el porcentaje de grasa intramuscular y ninguno de los tipos de fibras analizados

Evaluación de los tipos de fibras musculares en cerdos de raza chato murciano criados en sistema intensivo

Mediante técnicas histoquímicas y de análisis de imagen se estudian las características de los distintos tipos de fibras que integran el músculo longísimo lumbar del cerdo “Chato Murciano” criado mediante sistema intensivo. Asimismo, se estima y valora la presencia de fibras anómalas. Los resultados obtenidos demuestran la presencia de al menos tres tipos principales de fibras, catalogadas como tipos I, IIA y IIX. Los datos morfométricos revelan la existencia de alto porcentaje (79%) y gran tamaño de las fibras IIX (glucolíticas). Un 50 % de los animales analizados presentó fibras gigantes aunque en porcentajes muy escasos (<1%)