The obese Zucker rat develops
hyperlipidemia,
proteinuria and
focal glomerulosclerosis without prior changes in renal hemodynamics. To study the effects of oral
fatty acid intake on the development of renal injury in this model, rats were fed standard chow or chow supplemented with either 14%
fish oil or 14%
beef tallow after unilateral
nephrectomy at the age of 10 weeks. At 32 weeks post-
nephrectomy animals were sacrificed and renal tissue saved to assess histology and glomerular
eicosanoid production.
Fish-oil treated rats had lower mean plasma
cholesterol levels and developed less
proteinuria than control or
tallow-fed animals although there was no difference in plasma
creatinine or blood pressure. Histological analysis showed significantly fewer sclerosed glomeruli in the
fish oil group (4.0 +/- 0.8% vs. control 19.4 +/- 4.1%, P less than 0.0005 and vs.
beef tallow 10.8 +/- 1.9%, P less than 0.005). Glomeruli derived from rats on
fish oil supplements produced smaller amounts of
prostaglandin (PG)E2 and of the stable metabolites of PGI2 (6-oxo-PGF1 alpha),
PGF2 (
PGF2 alpha) and
thromboxane (TX)A2 (TXB2) than those from
tallow-fed animals. This study demonstrates that oral
fatty acid intake may influence the development of glomerulosclerosis. The apparent beneficial effects of
fish oil have not been fully defined, but may relate to favorable changes in plasma
lipid concentration and renal
eicosanoid production.