engleski

Lung fatty acid manipulations in low-fat diet

Specific composition of fatty acids of lung glycerophosphatides, particularly phosphatidylcholine, is essential for the physiological functions of the lung. Therefore it is important to determine possible exogenous factors which could affect structural changes of lung fatty acids. In this paper the effect of low-fat diet (LFD) on the composition of fatty acids of rat lung lipids is described. The LFD used was basically composed as follows: protein 11.94 %, carbohydrates 75.33 %, and fat 0.66 %. Control diet (CD) was isoenergetic (15 kJg-1 dry substance). During 14 days of the study, experimental animals had free access to food and water. Upon the completion of the experiment, the animals were sacrificed and total lipids (TL) extracted from the lungs and isolated with chloroform-methanol. In CD and LFD, 0.54 mg TL mg-1 and 0.35 mg TL mg-1 protein, respectively, were obtained. Total lipids were separated into individual lipid classes by thin layer chromatography. The following lipids were isolated: triacylglycerols (TG), free fatty acids (FFA), phosphatidylcholine (PC), phosphatidylethanolamine (PE), sphingomyelin (SPH) and cerebrosides (CRB). The composition of fatty acids of particular lung lipids was determined by gas chromatography. Results of the qualitative and quantitative analysis of fatty acids of particular lung lipids showed a marked increase in desaturation after LFD as compared to the control diet. This particularly refers to C16 fatty acids: PE 143.5 %, PC 95.6 %, and TG 66 %. In C18 fatty acids, desaturation was considerably lower, and was most pronounced in case of SPH (30.8 %). The results obtained indicated LFD to stimulate desaturation of the lung glycerophosphatide fatty acids, which may reflect on the composition of pulmonary surfactants and cellular membranes.

low-fat diet, lung, fatty acids, desaturation

nije evidentirano