Physiological responses of carp (Cyprinus carpio L.) to dietary exposure to zearalenone (ZEN)

Abstract

Zearalenone (ZEN) is a frequent contaminant of animal feeds, but systemic effects on fish and possible metabolic costs have not yet been investigated. In order to fill this gap a feeding trial with juvenile carp was conducted. The fish were fed ZEN-contaminated diets at three concentrations (low: 332 μg kg , and high: 797 μg kg −1 final feed, respectively) for four weeks. Possible reversible effects of ZEN were evaluated by feeding an additional group with the mycotoxin for four weeks period and the uncontaminated diet for further two weeks. After that possible ZEN effects on enzyme activities in kidney, spleen, liver and muscle tissue were investigated to get an organism-wide aspect of ZEN effects. Most organs appeared to (over)compensate ZEN effects during the exposure to this mycotoxin, which caused metabolic costs. Oxygen consumption increased in fish treated with the two higher ZEN concentrations via the diet. The differences between the treatments persisted also after the recovery phase of two weeks. Thus, the present study provided evidence of effects of ZEN on carbohydrate metabolism, lipid peroxidation in organs and metabolic oxygen demand. This is the first evidence for increased metabolic costs in a fish species due to exposure to the mycotoxin ZEN.

Dietary sodium heptanoate helps to improve feed efficiency, growth hormone status and swimming performance in gilthead sea bream (Sparus aurata)

“…Thus, common carp exhibits RMR values around 600 mgO 2 /kg/hr at 25.5°C (Pietsch & Junge, 2016), whereas the less active sole expends around 130 mg O 2 /kg/hr at 24°C (Lefrancois & Claireaux, 2003). In any case, swimming speed increases metabolic rates to overcome the drag offered by the water velocity, and our observations showed a linear increase in metabolic rates until they reach a maximal oxygen consumption that was comparable to measures reported for European sea bass, kept at 22-26°C under normoxic conditions (O 2 saturation >85%) (Claireaux, Couturier, & Groison, 2006).…”

“…These values are in accordance with the results reported in other teleosts, including the meagre (Peixoto et al., ), although these types of measures are highly influenced not only by water temperature and body size (Clarke & Johnston, ; Fry, ; Hulbert & Else, ; Lee et al., ), but also by the patterns of activity of each species. Thus, common carp exhibits RMR values around 600 mgO 2 /kg/hr at 25.5°C (Pietsch & Junge, ), whereas the less active sole expends around 130 mg O 2 /kg/hr at 24°C (Lefrancois & Claireaux, ). In any case, swimming speed increases metabolic rates to overcome the drag offered by the water velocity, and our observations showed a linear increase in metabolic rates until they reach a maximal oxygen consumption that was comparable to measures reported for European sea bass, kept at 22–26°C under normoxic conditions (O 2 saturation >85%) (Claireaux, Couturier, & Groison, ).…”

Influence of mycotoxins on fish health

“…Ponadto, opisano jego hepatotoksyczne, immunotoksyczne oraz genotoksyczne oddziaływanie na organizm ryb. Zearalenon może również powodować wystąpienie stresu oksydacyjnego (27). U karpi, którym podawano paszę z zearalenonem, obserwowano zwiększony metabolizm beztlenowy, którego wykładnikiem był wzrost poziomu dehydrogenazy mleczanowej (LDH) w mięśniach i skrzelach.…”

“…U karpi, którym podawano paszę z zearalenonem, obserwowano zwiększony metabolizm beztlenowy, którego wykładnikiem był wzrost poziomu dehydrogenazy mleczanowej (LDH) w mięśniach i skrzelach. Wzrost poziomu mleczanów zanotowano w surowicy krwi u ryb w okresie spoczynkowym, po zaprzestaniu podaży paszy zawierającej tę mikotoksynę (27). W badaniach prowadzonych na zarodkach danio pręgowanego (Danio rerio) wykazano zaburzenia w rozwoju.…”

“…(33) wykryli śladowe stężenia deoksyniwalenolu (< 1,6 µg/kg) w tkankach karpi karmionych paszą zamieszczoną toksyną w stężeniach 352-954 µg/kg. Ten sam zespół autorów wykazał niskie stężenia zearalenonu i jego metabolitu (< 0,23 µg/kg) w tkankach karpi karmionych paszą skażoną toksyną w stężeniach 332--797 µg/kg (27) Objaśnienie: X -nie wykryto pozostałości mikotoskyn (fumonizyna B1 i B2, toksyny T-2 i HT-2) brak jest informacji w dostępnym piśmiennictwie. Na podstawie opublikowanych wyników można stwierdzić, że nie ma zagrożenia dla konsumentów ze strony pozostałości mikotoksyn w mięśniach ryb (tab.…”