Dietary modulation of phospholipid fatty acid composition and lipoxygenase products in mouse lung homogenates

Abstract

This study investigated the potential of dietary fats to modulate the arachidonic acid content of mouse lung phospholipids and the formation of lipoxygenase products from arachidonic and eicosapentaenoic acids. Prior to breeding, female mice were fed for five months diets with 10 wt% of either olive oil, safflower oil, fish oil, or linseed oil. The same diets were fed to the females during gestation and to the pups from day 18 to day 42 postpartum. On day 42, the phospholipids were extracted from fresh lung tissue and separated into classes [phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylcholine (PC), and phosphatidylinositol (Pl)] by thin‐layer chromatography. Methyl esters of phospholipid fatty acids and unesterified fatty acids were analyzed by gas chromatography. At comparable dietary n‐3/n‐6 ratios, arachidonic acid was reduced 85 and 75% in lungs from mice fed linseed oil and fish oil, respectively, compared to lungs of safflower oil‐fed mice. Dietary fats affected the proportion of arachidonic acid in phospholipids in the order: PE>PS>PS>Pl. Following incubation of homogenized lung tissue, the total amount of 12‐lipoxygenase products was lowest in lungs from mice fed olive oil, and 12‐hydroxyeicosatetraenoic acid was lowest in incubated lungs from mice fed linseed oil. Comparison of the amounts of lipoxygenase substrate fatty acids in the individual phospholipids with the lipoxygenase products suggested that the major substrate pool for the 12‐lipoxygenase pathway in mouse lung homogenates was PC.

Direct modulation of G-proteins by polyunsaturated fatty acids: a novel eicosanoid-independent regulatory mechanism in the developing lung

“…Given the well-established relationship between alveolar fluid overload and neonatal respiratory disease [2], the identification of a possible link between AA-mediated signal transduction and alveolar Na + transport up-regulation at birth raises the important clinical question : is perinatal PUFA deficiency (prevalent in early infancy [13]) an unidentified aetiological factor for respiratory morbidity ? Antenatal dietary PUFA deficiency in mice directly reduces pup-lung phospholipid AA content [33], whereas dietary PUFA deficiency in infancy (in standard formula-fed compared with breast-fed infants) is associated with greater respiratory morbidity [34][35][36]. Surprisingly, this difference in morbidity persists for many years beyond the time when PUFA intake differed significantly between the two cohorts [35,36].…”