Characteristics of lipid and lymphocytes collected from the lymph of rats fed a low fat diet or high fat diets rich in N-6 or N-3 polyunsaturated fatty acids

Lymphatic fluid and lymphocytes were isolated from lymph collected by cannulation of the thoracic duct of rats which had been fed for six weeks on a low fat (LF) diet or on high fat diets with safflower oil (SO) or fish oil (FO) as the sources of fat. The fatty acid composition of lymphatic fluid was markedly influenced by that of the diet. There were significant linear correlations between the proportions of lauric, myristic, palmitic, palmitoleic, stearic, oleic and linoleic acids in the diet and in the lymphatic fluid. Eicosapentaenoic and docosahexaenoic acids appeared in the lymphatic fluid of rats fed the FO diet. The fatty acid composition of lymph lymphocytes was influenced by that of the diet fed, but the effects of diet were weaker than those upon lymphatic fluid. The principal effect was seen in cells from the FO-fed rats; these had a significantly lower proportion of arachidonic acid than cells from rats fed either of the other diets and they contained measurable proportions of eicosapentaenoic and docosahexaenoic acids. The amount and type of fat fed did not affect the proportions of CD4-positive, CD8-positive, CD11b/c-positive or kappa-light chain-positive lymph lymphocytes. Lymph lymphocytes from rats fed either the SO or FO diets proliferated less well than those from rats fed the LF diet. (C) 1998 Elsevier Science Inc.