Effects of dietary supplementation with n-3 fatty acids on kidney morphology and the fatty acid composition of phospholipids and triglycerides from mice with polycystic kidney disease.

The DBA/2FG-pcy strain of mouse has been developed as an animal model for adult polycystic kidney disease and we have determined the effects of feeding an n-3 fatty acid-enriched diet on kidney morphology and the fatty acid compositions of the constituent phospholipid and triglyceride fractions in this strain. Twelve male and female DBA/2FG-pcy mice were fed lab chow or semi-purified diets containing sunflower seed oil (SO) or a n-3 fatty acid-enriched concentrate (MaxEPA) for 60 days. At necropsy, blood and urine samples were taken and the kidneys processed for examination by light microscopy. Gas-liquid chromatography of the fatty acids in the kidney lipids was also performed. Male and female mice fed the MaxEPA-based diet tended to have lower mean kidney weights. Hematocrits, blood urea, and serum creatinine levels were similar among the lab chow-, SO- and MaxEPA-fed groups. All the groups exhibited a moderate hematuria; the incidence of this symptom was lowest in the MaxEPA-fed male animals. Extensive tubular dilatation was apparent in the cortices and medullae from the lab chow-fed animals; these lesions were slightly less severe in the SO-fed group and least severe in kidneys from the MaxEPA-fed animals. By morphometry, the renal area occupied by cysts was also lowest in the male Max-EPA-fed group; females fed the MaxEPA-based diet did not show a marked decrease in the proportion of kidney area occupied by cysts. Fatty acid compositions of the total phospholipid and triglyceride fractions from kidneys of male mice fed the MaxEPA-based diet showed a reciprocal replacement of the n-6 fatty acids with the n-3 fatty acids compared to kidneys from males fed the SO-based diet.