Forsøksdyr: Mechanisms behind modulation of methylmercury distribution and accumulation by dietary protein source

Godkjenningsdato 04.12.2018

Godkjenningsperiode 15.01.2019-15.01.2020

Methylmercury (MeHg) is an ubiquitous environmental contaminant known particularly for its potential neurotoxicity. Humans are mainly exposed to MeHg through consumption of contaminated fish and seafood. The distribution, accumulation and toxicity of MeHg can be altered through interaction with nutrients present in seafood (e.g. selenium). Results from a pilot study, investigating an effects of different whole food protein sources on MeHg distribution in mice following 90 days dietary exposure revealed, that the type of protein in the dietary matrix affects the tissue accumulation of MeHg independent of selenium levels.
Based on the results from the pilot study, we now aim to investigate the mechanisms underlying the observed interaction between the food protein matrix and tissue accumulation of MeHg in a 90-days dietary exposure study in BALB/c mice.

The animal experiment involves a number of 42 male BALB/c mice, determined based on statistical power analysis.
As this experiment aims to connect tissue distribution to different organismal responses, interpolation of effects observed from tissue or cell cultures is not possible. It is therefore essential that this work is performed using an animal model. The experimental procedure has been refined based on comparable previous studies, and the results of the study will contribute to refinement of future toxicological studies using casein as matrix.
The dose MeHg included in the feeding experiment is in accordance to the dose used in the pilot study, and has been shown to be sufficient to detect differences in tissue accumulation in the animals exposed through different diets. However, the dose is not expected to induce toxicity.
The experimental procedures have been refined in order to minimize stress imposed on the animals.
The results from the animal experiment will generate knowledge on the role of the dietary matrix in MeHg toxicology, which will contribute to future risk benefit evaluations of food, and particularly for MeHg exposure from fish and seafood.