Distribution of¹⁴C‐Ochratoxin A in the Rainbow Trout(Salmo gairdneri)

Abstract

The nephrotoxic mycotoxin ochratoxin A was studied in rainbow trout by whole‐body autoradiography and scintillation counting using 14C‐labelled toxin. After one single intravenous injection of 10 μCi/fish, corresponding to 160 ng toxin/g body weight, the tissue affinity was studied during an eight day period. As soon as 5 min. after injection the concentration of the radioactivity in the blood had dropped to one tenth of that in the kidney and the urinary bladder. The autoradiograms showed two patterns of blackening in the kidney, one diffuse in the pronephros and one very strong spotty blackening in the opistonephros. In addition to the kidney very high concentrations of radioactivity were also noticed in the bile and the pseudobranch. The muscular tissue of treated trouts contained almost no radioactivity during the whole experiment. Chemical analysis revealed that the radioactivity that could be extracted from the organs was mainly ochratoxin A.

Tissue distribution and elimination of deoxynivalenol and ochratoxin A in dietary-exposed Atlantic salmon (Salmo salar)

“…The results of the present study on the tissue distribution and elimination of OTA in Atlantic salmon confirmed previous findings of OTA toxicokinetics in rainbow trout and carp (Fuchs et al 1986;Hagelberg et al 1989). The low plasma concentrations detected in the final elimination experiment after 8 weeks in fish exposed to approximately 2.4 mg OTA kg -1 feed indicated a rather low bioavailability, similar to the low bioavailability observed in carp (1.6%).…”

“…The persistence of OTA in kidney as observed in rainbow trout (Fuchs et al 1986) has been attributed to renal reabsorption and is thought to explain kidney toxicity, a major effect in rodents and pig (Dietrich et al 2005). This might also be true for fish considering the specific distribution pattern in kidney found in a study with 14 C-labelled OTA (Fuchs et al 1986;Fuchs & Hult 1992) and also the elevated OTA concentrations in salmon kidney in the present study.…”

“…This might also be true for fish considering the specific distribution pattern in kidney found in a study with 14 C-labelled OTA (Fuchs et al 1986;Fuchs & Hult 1992) and also the elevated OTA concentrations in salmon kidney in the present study.…”

“…A further common feature appears to be the presence of a secondary peak in the OTA plasma concentrations, observed in rats, mice and cows, and now also in salmon muscle, kidney and liver, which was explained by a potential enterohepatic recirculation (Fuchs et al 1986;Fuchs & Hult 1992;Li et al 1997). OTA is hydroxylated by liver enzymes to a number of known products such as OTA-α, 4-OH-OTA and 10-OH-OTA (Wu et al 2011) that could be conjugated to glucuronides, excreted via the biliary route, split in the gastrointestinal tract and reabsorbed.…”

“…Moreover, the elimination half-life was shorter in fish (Hagelberg et al 1989). In another study, 14 C-labelled OTA was administered intravenously with a single dose in rainbow trout, and the tissue affinity was studied during an 8-day period by whole-body autoradiography (Fuchs et al 1986). The radioactivity disappeared rapidly from the blood and almost no distribution to muscle tissue was detected, whereas accumulation was detected in the posterior kidney and the bile duct.…”