Characterizing the influence of different sources of omega-3 polyunsaturated fatty acids on renal function and health in female rats

Evidence suggests that renal diseases in rodents may be modulated by dietary omega-3 polyunsaturated fatty acids (ω-3 PUFAs). Many sources of ω-3 PUFAs exist and it is unclear how each influences normal renal tissue. Therefore the objective of this study was to determine how different ω-3 PUFA sources influence renal health. Young (28 d) female Sprague-Dawley rats (n=10/group) were individually housed in metabolic cages. Rats were pair-fed 12% high fat diets consisting of corn (CO), flax (FO), menhaden (MO), krill (KO), salmon (SO), or tuna (TO) oils for 8 weeks, when rats were euthanized and serum and kidneys were collected. Renal mineral content was determined using inductively-coupled plasma spectrometry. Histological evaluation was performed on H&E stained kidney tissue. Serum measures of kidney function included total protein, albumin, blood urea nitrogen (BUN), creatinine, calcium (Ca), and phosphorus (P) measured by colorimetric reactions. KO-fed rats had heavier (P<0.001) kidneys compared to rats fed FO and MO. Rats fed KO also had the highest (P=0.003) kidney Ca content and displayed more evidence of renal damage by histology. Despite these differences, serum measures of kidney function were similar among the groups. Results suggest that high ω-3 PUFA intake as KO may result in structural damage of kidneys in the absence of functional changes.