Effects of graded levels of arachidonic acid on the reproductive physiology of Senegalese sole (Solea senegalensis): fatty acid composition, prostaglandins and steroid levels in the blood of broodstock bred in captivity

Previous studies on Senegalese sole (Solea senegalensis) indicated that cultured broodstock (first generation, G1) have lower tissue levels of arachidonic acid (20:4n-6, ARA) than wild counterparts. ARA is metabolized to form prostaglandins (PGs) that are involved in steroid production and follicle maturation in fish. In the present study the effects of different dietary levels of ARA on blood lipid and fatty acid composition, prostaglandin (PGF2α, PGF3α, PGE2 and PGE3) levels and plasmatic steroid levels (11-ketotestosterone, 11-KT, testosterone, T and estradiol, E2) in G1 Senegalese sole were studied. For this purpose, 12 groups of ten fish (1:1 male and female), were fed six diets (each diets was fed to two groups) with different dietary ARA levels over nine months (diets A = 0.7, B = 1.6, C = 2.3, D = 3.2, E = 5.0, F = 6.0% ARA). ARA and CHOL levels in blood showed a significant increase in an ARA dose related manner (P < 0.05) whereas EPA and EPA/ARA ratio were reduced. In males, steroid (11-KT and T) levels increased significantly with increasing dietary ARA in a dose dependent manner, whereas in females E2 did not show any change related to dietary ARA content. Plasma concentration of 3-series PGs (i.e., PGE3 and PGF3α) were reduced in parallel to increased ARA levels in blood (P < 0.05) and levels of PGs 3-series were always higher than 2-series PGs (PGE2 and PGF2α). In conclusion there is an effect of dietary ARA on steroid production of Senegalese sole males, which might have important consequences in the reproduction of cultured fish

APORTES A LA HISTORIA NATURAL DEL BAILARÍN CHICO O CACHIRLA COMÚN (ANTHUS CORRENDERA CHILENSIS)

Resumen ∙ El Bailarín Chico Común o Cachirla Común (Anthus correndera chilensis) es una de las seis subespecies del complejo A. correndera. Presenta una amplia distribución en Chile y Argentina, pero a pesar de ser un ave frecuente en su hábitat, el conocimiento de aspectos básicos de su historia natural es precario. Su distribución en Chile va desde la región de Atacama hasta Isla Navarino en la región de Magallanes, mientras que en Argentina estaría presente desde Laguna Seca, provincia de Mendoza hasta Tierra del Fuego a lo largo de los Andes, y desde Tierra del Fuego hasta el sur de la Provincia de Río Negro a lo largo de la costa Atlántica. En base a información generada en 10 localidades de Chile y Argentina, presentamos nuevos antecedentes sobre su distribución, abundancia, biometría, plumaje, canto y reproducción. A pesar de la gran cantidad de registros disponibles, hay áreas de su distribución en Argentina que requieren ser estudiadas con mayor detalle, pues se desconocen los límites con otras subespecies como correndera y catamarcae con las que podría sobreponerse. El plumaje presentó un patrón de muda similar a lo reportado para otras especies de Anthus, con una muda formativa, alterna y básica (estrategia alterna compleja). En total registramos un repertorio vocal de dos tipos de cantos: canto territorial y canto posado, y tres tipos de llamadas: de alerta, de reclamo y de solicitud de alimento de pichones. De este repertorio vocal el canto territorial es la vocalización más frecuente y compleja. Abstract ∙ Contributions to the natural history of the Correndera Pipit (Anthus correndera chilensis) Anthus correndera chilensis is one of the six subspecies of the Correndera Pipit. It is widely distributed in Chile and Argentina, but despite being common in its habitat, knowledge of essential aspects of its natural history is poor. Its distribution in Chile ranges from the region of Atacama to Isla Navarino in the Magallanes region, while in Argentina it is distributed from Laguna Seca, province of Mendoza to Tierra del Fuego along the Andes, and on a narrow strip along the Atlantic coast between Tierra del Fuego and the south of the Province of Río Negro. Based on information generated in 10 localities of Chile and Argentina, we present new information on distribution, biometry, vocalizations, breeding, and plumage/molting. Despite the large number of presence records available, there are areas of distribution in Argentina that require exploration. Because the boundaries with other subspecies, such as correndera and catamarcae, are incompletely known, range overlaps are likely. Plumage molt presented a pattern similar to that reported for other Anthus species, with a formative, alternate, and basic molting (alternate complex strategy) patterns. In total we recorded a vocal repertoire of two different song types: territorial and perched; and three call types: alert, complaint, and request of nestlings. Out of these, the most frequent and complex was the territorial song.

Arachidonic acid and eicosapentaenoic acid metabolism in juvenile Atlantic Salmon as affected by water temperature

Salmons raised in aquaculture farms around the world are increasingly subjected to sub-optimal environmental conditions, such as high water temperatures during summer seasons. Aerobic scope increases and lipid metabolism changes are known plasticity responses of fish for a better acclimation to high water temperature. The present study aimed at investigating the effect of high water temperature on the regulation of fatty acid metabolism in juvenile Atlantic salmon fed different dietary ARA/EPA ratios (arachidonic acid, 20:4n-6/ eicosapentaenoic acid, 20:5n-3), with particular focus on apparent in vivo enzyme activities and gene expression of lipid metabolism pathways. Three experimental diets were formulated to be identical, except for the ratio EPA/ARA, and fed to triplicate groups of Atlantic salmon (Salmo salar) kept either at 10°C or 20°C. Results showed that fatty acid metabolic utilisation, and likely also their dietary requirements for optimal performance, can be affected by changes in their relative levels and by environmental temperature in Atlantic salmon. Thus, the increase in temperature, independently from dietary treatment, had a significant effect on the β-oxidation of a fatty acid including EPA, as observed by the apparent in vivo enzyme activity and mRNA expression of pparα -transcription factor in lipid metabolism, including β-oxidation genes- and cpt1 -key enzyme responsible for the movement of LC-PUFA from the cytosol into the mitochondria for β-oxidation-, were both increased at the higher water temperature. An interesting interaction was observed in the transcription and in vivo enzyme activity of Δ5fad-time-limiting enzyme in the biosynthesis pathway of EPA and ARA. Such, at lower temperature, the highest mRNA expression and enzyme activity was recorded in fish with limited supply of dietary EPA, whereas at higher temperature these were recorded in fish with limited ARA supply. In consideration that fish at higher water temperature recorded a significantly increased feed intake, these results clearly suggested that at high, sub-optimal water temperature, fish metabolism attempted to increment its overall ARA status -the most bioactive LC-PUFA participating in the inflammatory response- by modulating the metabolic fate of dietary ARA (expressed as % of net intake), reducing its β-oxidation and favouring synthesis and deposition. This correlates also with results from other recent studies showing that both immune- and stress- responses in fish are up regulated in fish held at high temperatures. This is a novel and fundamental information that warrants industry and scientific attention, in consideration of the imminent increase in water temperatures, continuous expansion of aquaculture operations, resources utilisation in aquafeed and much needed seasonal/adaptive nutritional strategies

Dietary modulation of arachidonic acid metabolism in senegalese sole (Solea Sengalensis) broodstock reared in captivity

Previous studies have shown higher levels of arachidonic acid (20:4n-6, ARA) in testis, liver, and muscle of wild Senegalese sole (Solea senegalensis) compared to fish reared in captivity (first generation, G1). The present study was conducted to establish the optimal level of dietary ARA for G1 Senegalese sole broodstock, using as a reference the fatty acid profile of wild broodstock (gonads, liver and muscle). A total of 120 Senegalese sole broodstock were randomly distributed into 12 tanks (1:1 male and female) and fed in duplicate with six experimental diets containing increasing amounts of ARA (0.7%, 1.6%, 2.3%, 3.2%, 5.0%, and 6.0 % of total fatty acids) for 9months. The relative ARA levels in liver, muscle and male and female gonads at the end of the feeding period increased in a dose dependent manner. Dietary ARA was mainly incorporated and stored in testis or ovary, followed by liver and muscle. Fish fed 2.3% and 3.2% ARA showed no differences in the ARA content of testis, ovary and liver when compared to wild fish. In male fish, a significant increase in the levels of 22:4n-6 and 22:5n-6 fatty acids was also observed, which was consistent with the up-regulation of fatty acyl elongase (elovl5) and desaturase (d4fad) transcript levels in the liver of fish fed 0.7%, 2.3% and 6% ARA. These results suggest that dietary inclusion of 3.2% ARA during periods shorter than 9months, or of 2.3% ARA for prolonged periods, can maintain optimal levels of tissue ARA in captive Senegalese sole broodstock. In addition, the data indicate that male Senegalese sole is able to elongate and desaturate ARA to 22:4n-6 and 22:5n-6, suggesting that these fatty acids may be important for male reproduction

Escherichia coli heat-stable enterotoxin mediates Na+/H+ exchanger 4 inhibition involving cAMP in T84 human intestinal epithelial cells

The enterotoxigenic Escherichia coli strains lead to diarrhoea in humans due to heat-labile and heat-stable (STa) enterotoxins. STa increases Cl-release in intestinal cells, including the human colonic carcinoma T84 cell line, involving increased cGMP and membrane alkalization due to reduced Na+/H+ exchangers (NHEs) activity. Since NHEs modulate intracellular pH (pHi), and NHE1, NHE2, and NHE4 are expressed in T84 cells, we characterized the STa role as modulator of these exchangers. pHi was assayed by the NH4Cl pulse technique and measured by fluorescence microscopy in BCECF-preloaded cells. pHi recovery rate (dpHi/dt) was determined in the absence or presence of 0.25 μmol/L STa (30 minutes), 25 μmol/L HOE-694 (concentration inhibiting NHE1 and NHE2), 500 μmol/L sodium nitroprusside (SNP, spontaneous nitric oxide donor), 100 μmol/L dibutyryl cyclic GMP (db-cGMP), 100 nmol/L H89 (protein kinase A inhibitor), or 10 μmol/L forskolin (adenylyl cyclase activator). cGMP and cAMP were measured in cell extracts by radioimmunoassay, and buffering capacity (βi) and H+ efflux (JH +) was determined. NHE4 protein abundance was determined by western blotting. STa and HOE-694 caused comparable reduction in dpHi/dt and JH + (∼63%), without altering basal pHi (range 7.144-7.172). STa did not alter βi value in a range of 1.6 pHi units. The dpHi/dt and JH+ was almost abolished (∼94% inhibition) by STa + HOE-694. STa effect was unaltered by db-cGMP or SNP. However, STa and forskolin increased cAMP level. STa-decreased dpHi/dt and JH + was mimicked by forskolin, and STa + HOE-694 effect was abolished by H89. Thus, incubation of T84 cells with STa results in reduced NHE4 activity leading to a lower capacity of pHi recovery requiring cAMP, but not cGMP. STa effect results in a causal phenomenon (STa/increased cAMP/increased PKA activity/reduced NHE4 activity) ending with intracellular acidification that could have consequences in the gastrointestinal cells function promoting human diarrhoe

Oil from transgenic Camelina sativa containing over 25 % n-3 long-chain polyunsaturated fatty acids as the major lipid source in feed for Atlantic salmon (Salmo salar)

Facing a bottleneck in the growth of aquaculture, and a gap in the supply and demand of the highly beneficial omega-3 (n-3) long-chain polyunsaturated fatty acids (LC-PUFA), sustainable alternatives to traditional marine–based feeds are required. Therefore, in the present trial, a novel oil obtained from a genetically engineered oilseed crop, Camelina sativa, that supplied over 25 % n-3 LC-PUFA was tested as a sole dietary added lipid source in Atlantic salmon (Salmo salar) feed. Three groups of fish were fed for 12 weeks three experimental diets with the same basal composition and containing 20 % added oil supplied by either a blend of fish oil and rapeseed oil (1:3) (COM) reflecting current commercial formulations, wild-type Camelina oil (WCO) or the novel transgenic Camelina oil (TCO). There were no negative effects on the growth, survival rate or health of the fish. The whole fish and flesh n-3 LC-PUFA levels were highest in fish fed TCO with levels almost and more than 2-fold higher compared to those of fish fed the COM and WCO diets, respectively. Diet TCO had no negative impacts on the evaluated immune and physiological parameters of head kidney monocytes. The transcriptomic responses of liver and mid-intestine showed only mild effects on metabolism genes. Overall, the results clearly indicated that the oil from transgenic Camelina was highly efficient in supplying n-3 LC-PUFA providing levels double that obtained with a current commercial standard, and similar to those a decade ago prior to substantial dietary fishmeal and oil replacement

Algae in fish feed: performances and fatty acid metabolism in juvenile Atlantic Salmon

Algae are at the base of the aquatic food chain, producing the food resources that fish are adapted to consume. Previous studies have proven that the inclusion of small amounts (<10% of the diet) of algae in fish feed (aquafeed) resulted in positive effects in growth performance and feed utilisation efficiency. Marine algae have also been shown to possess functional activities, helping in the mediation of lipid metabolism, and therefore are increasingly studied in human and animal nutrition. The aim of this study was to assess the potentials of two commercially available algae derived products (dry algae meal), Verdemin (derived from Ulva ohnoi) and Rosamin (derived from diatom Entomoneis spp.) for their possible inclusion into diet of Atlantic Salmon (Salmo salar). Fish performances, feed efficiency, lipid metabolism and final product quality were assessed to investigated the potential of the two algae products (in isolation at two inclusion levels, 2.5% and 5%, or in combination), in experimental diets specifically formulated with low fish meal and fish oil content. The results indicate that inclusion of algae product Verdemin and Rosamin at level of 2.5 and 5.0% did not cause any major positive, nor negative, effect in Atlantic Salmon growth and feed efficiency. An increase in the omega-3 long-chain polyunsaturated fatty acid (n-3 LC-PUFA) content in whole body of fish fed 5% Rosamin was observed

Inclusion of oil from transgenic Camelina sativa in feed effectively supplies EPA and DHA to Atlantic salmon (Salmo salar) grown to market size in seawater pens

Atlantic salmon were fed either a diet reflecting current commercial feeds with added oil supplied by a blend of fish oil and rapeseed oil (COM), or a diet formulated with oil from transgenic Camelina sativa containing 20% EPA+DHA (TCO). Salmon were grown from smolt to market size (>3kg) in sea pens under semi-commercial conditions. There were no differences in growth, feed efficiency or survival between fish fed the TCO or COM diets at the end of the trial. Levels of EPA+DHA in flesh of salmon fed TCO were significantly higher than in fish fed COM. A 140g fillet from TCO-fed salmon delivered 2.3g of EPA+DHA, 67% of the weekly requirement level recommended by many health agencies, and 1.5-fold more than the 1.5g of EPA+DHA for COM-fed fish. Oil from transgenic Camelina supported growth and improved the nutritional quality of farmed salmon in terms of increased “omega-3” supply for human consumers

Inclusion of oil from transgenic Camelina sativa in feed effectively supplies EPA and DHA to Atlantic salmon (Salmo salar) grown to market size in seawater pens

Atlantic salmon were fed either a diet reflecting current commercial feeds with added oil supplied by a blend of fish oil and rapeseed oil (COM), or a diet formulated with oil from transgenic Camelina sativa containing 20% EPA+DHA (TCO). Salmon were grown from smolt to market size (>3kg) in sea pens under semi-commercial conditions. There were no differences in growth, feed efficiency or survival between fish fed the TCO or COM diets at the end of the trial. Levels of EPA+DHA in flesh of salmon fed TCO were significantly higher than in fish fed COM. A 140g fillet from TCO-fed salmon delivered 2.3g of EPA+DHA, 67% of the weekly requirement level recommended by many health agencies, and 1.5-fold more than the 1.5g of EPA+DHA for COM-fed fish. Oil from transgenic Camelina supported growth and improved the nutritional quality of farmed salmon in terms of increased “omega-3” supply for human consumers

Incidencia de patología oral y relación con barreras de acceso en adultos mayores de Talca

70 p.Introducción: La población mundial está envejeciendo y la mayor expectativa de vida y precariedad de cobertura odontológica conlleva a que se incrementan los problemas de salud bucodental. De esta forma la falta de equidad en el acceso y utilización de los servicios de salud bucal representa una amenaza para la población de adultos mayores. Objetivo: Determinar la relación entre barreras de acceso percibidas en salud y salud bucodental en adultos mayores pertenecientes a clubes en la comuna de Talca, seguimiento de 2 años (2015-2016 a 2017-2018). Metodología: Estudio de cohorte prospectivo durante los años 2015-2018. Se estudió una muestra aleatoria de clubes de adultos mayores de Talca de 408 sujetos en línea base y seguimiento efectivo de 108. Se les aplicó una encuesta y examen físico para determinar su estado de salud oral. Se calculó incidencia acumulada, prevalencia y riesgo relativo de barreras de acceso percibidas y algunas patologías bucodentales. Resultados: A los 2 años se produce una disminución 6,98% en la cantidad de dientes presentes, incidencia acumulada para caries 23,68% y de edentulismo 4,22%. El 94,44% de los pacientes necesita prótesis dental. La principal barrera de acceso percibida corresponde a la económica. Las barreras actúan como factor protector para caries y de riesgo para dientes perdidos. Conclusión: A medida que pasan los años, se evidencia un aumento progresivo de lesiones de caries y pérdida de dientes. Si bien existe el GES de 60 años, este debería incorporar el control continuo para garantizar mejores condiciones de salud. Palabras claves: Adultos mayores, Caries dental, Perdida de diente, Barreras, Incidencia