Dietary n-3 fatty acids influence the lipid composition and physical properties of liver microsomal membranes in diabetic rats

• Published in: Prostaglandins, leukotrienes and essential fatty acids leukotrienes and essential fatty acids, 1997-03, Vol.56 (3), p.245-252
• Main Authors: Igal, A., de Gómez Dumm, N.T.
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Biophysical Phenomena; Biophysics; Diabetes Mellitus, Experimental - metabolism; Diabetes. Impaired glucose tolerance; Endocrine pancreas. Apud cells (diseases); Endocrinopathies; Etiopathogenesis. Screening. Investigations. Target tissue resistance; Fatty Acids, Omega-3 - administration & dosage; Fatty Acids, Omega-3 - metabolism; Fluorescence Polarization; Intracellular Membranes - chemistry; Intracellular Membranes - metabolism; Lipid Metabolism; Lipids - chemistry; Male; Medical sciences; Microsomes, Liver - chemistry; Microsomes, Liver - metabolism; Rats; Rats, Wistar
• ISSN: 0952-3278; 1532-2823
• DOI: 10.1016/S0952-3278(97)90543-3

We examined the effect of n-3 fatty acid consumption on the lipid composition and physical properties of liver microsomal membranes in normal and experimental diabetic rats. Lipid analysis showed a significant increase in the cholesterol:phospholipid ratio in membranes of normal animals fed n-3 fatty acids as well as in both groups of diabetic rats. These changes would be in part responsible for the higher fluorescent polarization of DPH (1,6-diphenyl-1,3,5 hexatriene) observed in the diabetic groups compared with the normal ones. These alterations were partially compensated by an increase in the amount of phosphatidylcholine in the diabetic rats fed on n-3 fatty acids. However, proteins also play a role in determining the physical properties of the liver microsomes because in the liposomes derived from them, the fluorescent polarization of DPH decreased in the diabetics fed n-3 fatty acids. Measurements of fluorescence anisotropy of n-AS (2-, 7 and 12 (9 anthroyloxy) stearic acid) probes revealed a restricted rotational mobility in the middle zone of the bilayer. Consistently with this finding there was an elevation in the calculated unsaturation density of the fatty acids at the carbon 8 position. These experiments confirm the lipid abnormalities that take place in experimental diabetes and they show further that n-3 fatty-acid administration causes certain compensatory, and thus beneficial, changes in these abnormalities.