Study On The ω-3 Polyunsaturated Fatty Acids

Objective To explore the relationship between theω-3 polyunsaturated fatty acids and aggressive behavior in mice.Methods Fifty-four male, four-week-old, Kunming mice were divided into three groups randomly:control group, fish oil group and simvastatin group, each mouse was isolating-raised and was numbered. Other eighteen mice, the aggressive reference which only applied in the aggressive evaluation, without any intervention, were grouping-raised and were also numbered. The mice of control group, fish oil group, simvastatin group were adaptive isolated-rearing for four weeks firstly, from the fifth week, the mice of control group were given normal saline 0.5mL/d respectively, the mice of fish oil group were given fish oil (the content of EPA and DHA is 30%) 0.72g/Kg/d respectively, and the mice of simvastatin group were given simvastatin 0.02g/Kg/d respectively, each reagent was given intragastrically and the intervention lasted for consecutive twelve weeks. At the beginning and end of the intragastric administration, the aggression of each mouse was evaluated by recording the latent period of assault, the frequencies of tail swing, the frequencies of assault and the cumulative time of assault. After the last aggressive evaluation, the mice were killed by decapitation and the brains were collected, then the contents of the eicosapentaenoic acid and the docosahexaenoic acid were determined by Gas Chromotography-Mass Spectromemtry.Results (1) After a twelve-week intragastric administration and isolated-rearing, the latent period of assault of the mice in the control group was shortened. The frequencies of tail swing, the frequencies of assault and the cumulative time of assault were increased. (2) In the mice of fish oil group, no significant differences were occurred in the latent period of assault, the frequencies of tail swing, the frequencies of assault and the cumulative time of assault before and after the intervention. (3) In the mice of simvastatin group, the latent period of assault was shortened, the frequencies of tail swing, the frequencies of assault, the cumulative time of assault were increased, and the extent of reduce and increase were significantly larger than that in the control group. (4) After the intervention, the differences of the latent period of assault, the frequencies of tail swing, the frequencies of assault and the cumulative time of assault among the three groups were significant(P<0.05). (5) After the intervention, the content of eicosapentaenoic acid in the control group, the fish oil group, the simvastatin group was 1.67±0.37μg/mg,2.02±0.39μg/mg,1.41±0.32μg/mg respectively. (6)After the intervention, the content of docosahexaenoic acid in the control group, the fish oil group and the simvastatin group was 5.50±0.69μg/mg,6.39±0.80μg/mg and 4.98±0.98μg/mg. (7) The contents of EPA and DHA were positively correlated to the latent period of assault, but were negatively correlated to the frequencies of tail swing, the frequencies of assault and the cumulative time of assault.Conclusion A certain causal relationship was confirmed between theω-3 polyunsaturated fatty acids and the aggressive behavior induced by stress in mice.