N-3 and N-6 phosphoglyceride fatty acids in relation to in vitro erythrocyte haemolysis induced by hydrogen peroxide in captive common marmosets (Callithrix jacchus).

1. Hydrogen peroxide-induced haemolysis (HPIH) was studied in the red blood cells of the common marmoset monkey (Callithrix jacchus) in relation to the composition of the membrane fatty acids. HPIH (%) was surprisingly high (mean 41% +/- 34; median 33.4%) and significantly different (P less than 0.001) from the corresponding value in healthy human subjects (mean 0.98% +/- 0.6; median 1.3%). 2. It was negatively correlated with 18:2n-6 (r = -0.76, P less than 0.001), 18:2n-6/20:4n-6 (r = -0.70, P less than 0.005) and 18:2n-6/22:6n-3 (r = -0.44, P less than 0.025) in the ethanolamine phosphoglycerides of the erythrocytes. 3. A shift in the n-6/n-3 balance in favour of the n-3 in the fatty acid composition of the membrane may have predisposed the red blood cells to haemolysis. 4. An increase in 22:6n-3, and a decrease of 20:4n-6 and 18:2n-6, may have been the result of feeding a diet containing fish products rich in long chain n-3 fatty acids.