Polycystic kidney disease (PKD) is a life-threatening disease characte
rized by focal dilatations or cysts in certain kidney tubules. Changes
(i. e. thickening) in the support structure for these tubules, the ba
sement membrane, have been related to the development of the cysts. An
alysis of changes in basement membranes of humans with PKD is difficul
t, however, due to the restricted amount of material available for stu
dy. Several genetic and induced animal models, including diphenylamine
-treated rats, have been employed to study the effects of PKD on basem
ent membrane synthesis. While all these studies agree that PKD has a s
ignificant influence on basement membranes, no clear understanding as
to how PKD effects basement membrane composition has emerged. Here, we
report our findings of the effect of diphenylamine treatment on the c
omposition of the basement membrane. Our immunohistological studies in
dicate that bamin, a recently described glycoprotein associated with g
lomerular basement membranes (Robinson et al., 1989), is not present i
n the glomerular basement membranes of diphenylamine-treated mice. Thi
s finding was confirmed by analysis of the composition of the basement
membrane matrix synthesized by EHS tumors grown in control and diphen
ylamine-treated mice. The possible role of bamin in the pathogenesis o
f renal cysts is discussed.