Nephrology Dialysis Transplantation, Vol 13, Issue 9 2227-2233, Copyright © 1998 by Oxford University Press
S Higueruelo, M Vaquero, C Pastor, R Galimany and R Romero
Background: To date, the role of dietary cholesterol
as a risk factor for some diabetic nephropathy, such as mesangial expansion
and glomerular lesions, is unknown. Controversy also exists regarding the
effects of prostaglandin-induced changes in glomerular haemodynamics on the
appearance of glomerulo-sclerosis. Methods: We have
used obese Zucker rats (OZRs) as a model of early nephropathy to evaluate
the effect of hypercholesterolaemic diet on glomerular prostaglandin
secretion and on the development of glomerular lesions. Due to the role of
angiotensin II (Ang II) in glomerular haemaodynamics, we have also
evaluated its effects on glomerular eicosanoid secretion. Furthermore, as
it has been suggested recently by clinical studies that
angiotensin-converting enzyme inhibitors (ACEIs) reduce serum lipids
associated with proteinuria, we have also evaluated the effect of the ACEI,
fosinopril, both in vivo and in
vitro, using 24 h glomeruli cultures.
Results: Results showed that a cholesterol-rich diet
significantly increased serum cholesterol, proteinuria and glomerular
eicosanoid secretion, and caused macrophage-ED1 cell deposits in the
glomerular mesangium. Segmentary lesions only appeared in those rats with
the highest percentage of glomerular xanthomatous (macrophage-ED1) cells.
Ang II, per se, caused a marked rise in glomerular
prostaglandin E2 and thromboxane B2. The inhibition of Ang II synthesis
with fosinopril reduced all the parameters listed above whereas Ang II
(10-6 M) increased the secretion of TxB2 and tended
to increase PGE2 secretion in glomerular culture.
Conclusions: In conclusion, exogenous cholesterol
per se may contribute to nephropathy by increasing
eicosanoid secretion, serum lipid profile, urinary protein excretion and
the development of glomerular lesions. Fosinopril reduced all these
parameters probably by its effects on Ang II. Key
words: angiotensin-converting enzyme inhibitors; angiotensin II;
eicosanoid secretion; incipient glomerular lesion; macrophage-ED1 cells;
nephropathy; xanthomatous cells
ORIGINAL ARTICLES
Fosinopril ameliorates exogenous cholesterol-induced incipient glomerular lesions in obese Zucker rats. Effects on eicosanoid secretion
Nephrology Department, Hospital Universitari Germans Trias i Pujol, E-08916 Badalona, Spain; Corresponding author
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