Variations on stress defences and metallothionein levels in the Senegal sole, Solea senegalensis, during early larval stages

Abstract

The biochemical status of antioxidant defences of larvae from the commercial, benthic fish, Solea senegalensis, were studied over a period of 28 days from hatching. The parameters studied were: catalase (EC 1.11.1.6), total glutation peroxidase activity (sum of the selenium dependent and independent forms) (EC 1.6.4.2), DT-diaphorase (EC 1.6.99.2), and as an indication of conjugative detoxifying metabolism, the enzyme glutathione S-transferase (GST; EC 2.5.1.18). Oxidative damage was evaluated by the formation of malondialdehyde (MDA) as an indication of lipid peroxidation (LP). Metallothionein (MT) levels were measured by differential pulse polarography and stress proteins (HSP 70 and HSP 60) were detected by immunoblotting, using commercial antibodies. The presence of catalytic activities was observed from hatching day and tended to increase during larval development. Significant changes were seen in most enzymes at day 3, when the larvae finished their endogenous feeding and started to feed on rotifers. DT-diaphorase activities were similar in both NADH and NADPH-dependent forms and, in turn, were about 10-times lower than their correspondent reductases. LP sharply increased at 19 and 28 days post-hatch (dph), suggesting a saturation of the antioxidant defences during metamorphosis. MT showed high values during the endogenous phase and the lowest value corresponded to day 3, when the egg-yolksac was fully reabsorbed; a steady-state value was reached thereafter. Stress proteins were present at all stages, showing distinctiveness in the molecular weight of HSP60 at hatching day and 1 dph. Quantitatively, both forms were significantly elevated at 3 dph, with their ratio (HSP70/HSP60) decreasing over time.Abbreviations: CAT -catalase; GST -glutathion S-trasferase; dph -days post hatch; DT-D -DTdiaphorase (NAD(P)H quinone oxidoreductase); DCPIP -dichlorophenol indophenol; HSP -heat shock protein; LP -lipid peroxidation; MDA -malondialdehide; MT -metallothionein; PUFA -polyunsaturated fatty acids; ROS -reactive oxygen species; t-GPX -total glutathion peroxidase.

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“…In the present study, the amount of total protein decreased significantly throughout the yolksac stage. Related to protein quantities, the results found in O. mykiss yolk-sac larvae agree with studies given before but did not agree with studies Mourente and Vázquez, (1996), Parra et al, (1999) and Mourente et al, (1999), Solé et al, (2004).…”

“…As a result, lipid peroxidation in the 19 days yolk-sac larvae was significantly lower. Similarly, in Dentex dentex larvae, the prooxidant status and lipid peroxidation declined over the 9-day period study (Mourente et al, 1999) but, in Solea senegalensis, lipid peroxidation in the 19 and 28 days was significantly higher during early larval stages (Solé et al, 2004). …”

“…The tripeptide (γ-glutamatic acid, cysteine and glycine) reduced glutathione (GSH) plays a key role in protection against oxidative stress by directly scavenging ROS (Leggatt and Iwama, 2009) and by regenerating the antioxidant vitamins C and E from their oxidized products (Lee and Dabrowski, 2003;Gao et al, 2014). GSH is synthesised intracellulary and oxidized to GSSG in a reaction catalysed by selenium-dependent glutathione peroxidase (SeGSHpx) and the GSHpx activity of certain isoforms of glutathione S-transferase (GSH) (Solé et al, 2004;Halliwell and Gutteridge, 2007). Both sources of GSHpx activity are able to detoxify organic peroxides produced by lipid peroxidation.…”

Physiological pathways involved in nutritional muscle dystrophy and healing in European sea bass (Dicentrarchus labrax) larvae

“…Similar findings have 465 been described in Senegalese sole (Solea senegalensis) larvae (Solé et al, 2004). These 466 results may indicate that despite of increase in AOE, this was not enough to counteract 467…”

Stress Biomarkers in Juvenile Senegal Sole, Solea senegalensis, Exposed to the Water-Accommodated Fraction of the “Prestige” Fuel Oil

“…1-chloro-2,4-dinitrobenzene (CDNB) was used as substrate, the final reaction mixture containing 1 mM CDNB and 1 mM of GSH (reduced glutathione). Measurement was done in a microplate reader for 3 min at 340 nm following the methodologies described elsewhere (Solé et al 2004(Solé et al , 2005Fernández-Díaz et al 2006). Total protein content.…”