Fatty Acids of Liver, Cardiac and Adipose Tissues from Copper-Deficient Rats

The effect of copper deficiency on liver, cardiac and adipose fatty acids was studied in the Long-Evans rat. Rats were fed diets adequate in copper (8.5 mg Cu/kg diet, group AC, n = 10) or with no added copper (0.4 mg Cu/kg diet, group NC, n = 9) or were pair-fed an adequate copper diet in amounts eaten by group NC rats (group PF, n = 10), from weaning until 8 wk thereafter. Group NC rats exhibited typical copper deficiency signs such as decreased body weight, hematocrit and liver copper levels but increased heart/body weight ratios. Adipose and cardiac triglycerides of group NC rats had greater 18:0 to 18:1n-9 ratios. All tissues in group NC rats had higher levels of longer-chain polyunsaturated fatty acids in triglycerides than those in AC or PF rats. Specifically, the following triglyceride fatty acids were in greater concentration in NC rats than in AC or PF rats: for liver, 18:2n-6, 22:5n-6, 22:5n-3 and 22:6n-3; for cardiac, 20:3n-6, 20:4n-6, 22:5n-3 and 22:6n-3; and for adipose, 20:3n-6, 20:4n-6 and 22:5n-6. Liver phospholipids had lower levels of 20:4n-6 in NC rats than in AC or PF rats. These results suggest that copper deficiency results in the accumulation of both n-3 and n-6 longer-chain polyunsaturated fatty acids in triglycerides of various tissues.