Background. A spontaneously hypercholesterolemic Imai rat has recently been
reported as a model of focal glomerulosclerosis that causes nephrotic synd
rome followed by renal failure. This study was designed to determine if an
oral adsorbent, AST-120, ameliorates renal lesions and TGF-beta 1 expressio
n in the rats.
Methods. AST-120 was given orally to the Imai rats for 32 weeks, and renal
function and pathology were compared between the AST-120-administered and c
ontrol Imai rats.
Results. AST-120-administered rats showed significantly lower levels of blo
od urea nitrogen, serum creatinine, urinary protein, serum total-cholestero
l, serum triglyceride, and serum and urinary indoxyl sulfate: and significa
ntly higher levels of serum albumin and creatinine clearance than control r
ats. AST-120 reduced the glomerular sclerosis index, interstitial fibrosis
area, and the extent of glomerular lipid deposition. Immunohistochemistry d
emonstrated that AST-120 reduced the expression of transforming growth fact
or (TGF)-beta 1 and tissue inhibitor of metalloproteinase (TIMP)-1 as well
as interstitial infiltration of macrophages in the renal cortex of the Imai
rats.
Conclusions. AST-120 prevented the progression of nephrotic syndrome and re
nal failure in the Imai rats by ameliorating glomerular sclerosis and inter
stitial fibrosis, accompanied with reduced expression of TGF-beta 1 and TIM
P-1, and reduced infiltration of macrophages in the kidneys.