Long-term n-3 fatty acid deficiency induces no substantial change in the rate of protein synthesis in rat brain and liver

The influence of long-term n-3 fatty acid deficiency on the rate of protein synthesis in rat brain and liver was investigated in relation to learning behavior or a presumed survival time-shortening factor (SSF) in rapeseed oi l, using a large-dose [H-3]phenylalanine (Phe) injection method. When Wista r rats were made n-3 fatty acid-deficient by feeding a safflower oil (alpha -linolenate-deficient) diet for 2 generations, conditions under which the s afflower oil group had been shown to exhibit altered learning behaviors, co mpared with the perilla oil group, no significant changes in the rate of pr otein synthesis were observed compared with the perilla oil (alpha-linolena te-sufficient) or rapeseed oil (alpha-linolenate-sufficient but SSF-contain ing) groups. However, the rapeseed oil group had a reduced specific radioac tivity of free Phe in the cerebral cortex, compared with the safflower oil group, In contrast to the reported observation of very long-term n-3 fatty acid deficiency inducing an almost 2-fold increase in the rate of protein s ynthesis in the brain, our results indicate that altered learning behavior resulting from n-3 fatty acid deficiency in rats is not associated with any substantial changes in the rate of protein synthesis in the brain.