1062-3604/04/3501- © 2004
Russian Journal of Developmental Biology, Vol. 35, No. 1, 2004, pp. 49–56. Translated from Ontogenez, Vol. 35, No. 1, 2004, pp. 61–69.
Original Russian Text Copyright © 2004 by Toivonen, Nefedova, Sidorov, Yurovitskii.
A severe eye disease has recently appeared in fry of
commercially important salmon species at ﬁsh hatcher-
ies of Karelia: “white eye” (cataract). The study of
optomotor reaction of vision acuity in salmon fry
reared at the Kemsky and Vygskii ﬁsh hatcheries
showed that up to 30% of ﬁsh had a weak vision, while
up to 35% of all reared ﬁsh fully lost vision.
The study of pathogenesis of this disease suggested a
nuclear form of cataract in ﬁsh. Other forms of cataract
and pathological changes, such as lens underdevelop-
ment and pupil constriction, occurred less frequently.
Cataract appears already during the ﬁrst year of ﬁsh rear-
ing, at the age of two–three months. The lake salmon and
char proved to be the most susceptible to this disease.
Since the parasitic form of cataract is excluded as a
result of preliminary studies, the alimentary factor is
the most probable cause of cataractogenesis.
Determination of food components, whose lack
could have induced cataract, requires a lot of time and
is rather costly but the reliability of the results is not
guarantied. At the same time studies of biochemical
status and metabolism in ﬁsh with cataract, as com-
pared to healthy ﬁsh, opens new possibilities in estima-
tion of food quality.
In addition, since the pathological changes during
cataractogenesis in ﬁsh, other animals, and man have
similar biochemical basis (oxidative damage of lipids
and proteins, destruction of lens ﬁber membranes, and
disturbed formation of high molecular weight aggre-
gates), the ﬁsh as a model represent a special interest.
In this work, we analyzed the composition of mem-
brane lipids in the salmon fry lens and pattern of fatty
acid spectra of these lipids during cataractogenesis. It
was shown that redistribution of lipid fractions takes
place and the ratio cholesterol/lipids (CL/PL)
The development is accompanied by enhanced anti-
oxidant activity of the lens tissue related to a decreased
concentration of malone dialdehyde (MDA). On the con-
trary, cataractogenesis is accompanied by enhanced free
radical oxidation and MDA accumulation. The enhanced
oxidative processes are accompanied by a decreased
content of glutathione and fatty acid-soluble vitamins.
Cataractogenesis is synchronized with a decreased activ-
ity of the proteolytic enzyme calpain, which, in combi-
nation with other factors, leads to the lens opacity.
MATERIALS AND METHODS
Studies were carried out on one and two year old
salmons reared at the Vygskii ﬁsh hatchery. We studied
the lenses of healthy ﬁsh and ﬁsh with cataract. The ﬁsh
kept on food, which did not induce cataract, was used
as a general control. Among ﬁsh kept on the artiﬁcial
food RGM, those with mature nuclear cataract were
selected, for which the lenses were studied under a
BIOCHEMISTRY OF DEVELOPMENT
Age-Related Features of Cataractogenesis in Salmon Fry.
2. Biochemical Features of Lens during Cataractogenesis
L. V. Toivonen*, Z. A. Nefedova**, V. S. Sidorov**
, and Yu. G. Yurovitskii***
* Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences,
pr. M. Toreza 44, St. Petersburg, 194223 Russia
Institute of Biology, Karel Scientific Center, Russian Academy of Sciences, ul. Pushkinskaya 11, Petrozavodsk, 185610
*Kol’tsov Institute of Developmental Biology, Russian Academy of Sciences, ul. Vavilova 26, Moscow, 119991 Russia
E-mail: Lolita@iephb.ru; firstname.lastname@example.org
Received October 19, 2000; in ﬁnal form, May 24, 2001
—We studied biochemical features of the lipid and phospholipid composition and patter of fatty acid
spectra in lenses of one and two year old salmons bearing cataracts. The lipid complex of lenses of diseased ﬁsh
underwent signiﬁcant changes. Cataractogenesis was accompanied by enhanced free radical oxidation and
accumulation of malone dialdehyde in lenses of salmons of various ages. The intensiﬁcation of oxidative pro-
cesses was synchronized with the decreased level of antioxidant protection (reduced glutathione, vitamins A
and E). The activity of Ca
-dependent proteolytic enzymes in lenses was determined and its decrease in the
case of cataract was shown.
: cataractogenesis, lens, salmon fry.