Abstract
The purpose of this study was to determine if feeding diets supplemented with n-3 fatty acids would result in reduced levels of arachidonic acid in major phospholipids, free fatty acid (FFA), and diacylglycerol (DAG) fractions of the salivary glands. Phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine plus phosphatidylinositol, FFA, and DAG fractions were isolated from the submandibular salivary glands (SMSG) of rats fed nutritionally adequate, semi-purified diets enriched with n-6 or n-3 fatty acids for 6 weeks. The fatty acid composition of the major phospholipids present in the SMSG and the concentrations of arachidonic acid were measured by gas chromatography-mass spectrometry after the addition of 18:4n-3 as an internal standard and transesterification. Arachidonic acid concentrations were significantly lower in each of the lipid fractions of the SMSG of rats fed diets rich in n-3 fatty acids than those of the control group. The results suggest that the diet-induced decrease in the potentially available sources of free arachidonic acid may result in a decrease in the levels of endogenous PGE
2 and in vitro synthesis of LTC
4, which was previously observed in the SMSG of rats fed diets containing n-3 fatty acids.