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Changes in the lipid composition of rainbow trout (Salmo gairdnerii) fed cyclopropenoid fatty acids

Rainbow trout were fed semi-purified diets containing cyclopropenoid
fatty acids, and the biological effects of these acids were
investigated. These fatty acids occur naturally in cottonseed oil and
have been implicated in a large number of physiological disorders.
Included in this study was an investigation of the pattern of deposition
of cyclopropenes per se in trout tissue lipids, as well as the effect
of these cyclopropenes on the deposition of other fatty acids. Other
effects such as growth, liver size and histology were also noted.
The ingestion of methyl sterculate, 2-octyl-1-cyclopropene-1-
octanoic acid, by rainbow trout resulted in the deposition of intact
cyclopropene in the body tissue. The accumulation in both the muscle
and depot lipid reached a level approximately equivalent to that
in the diet. This cyclopropene existed as the unaltered sterculate in the tissue triglycerides as shown by GLC analysis and was approximately
equal to that predicted by the Halphen determination.
A method was developed whereby trout liver lipid could be
quantitatively analyzed for CPFA using a modified Halphen color
reaction. This method was limited, however, by the small amounts
of lipid normally available in trout liver.
Ingestion of CPFA by rainbow trout resulted in reduction of
growth. This effect was characterized by a large growth suppression
early in the feeding period followed by a more normal pattern
of gain. Dietary levels of 100 ppm and 200 ppm methyl sterculate
resulted in identical effects.
Livers from trout fed CPFA were typically enlarged and very
firm as compared to normal trout livers. They also displayed a
marked lack of pigmentation. Histological examination revealed extreme
damage due to increased fatty infiltration and deposition. This
phenomenon appeared to be most extreme during the early stages of
feeding.
Dietary cyclopropenoid fatty acids induced certain changes in
the pattern of fatty acid deposition in rainbow trout. This alteration
was characterized by a rapid increase in the concentration of stearic
acid in the tissue, which resulted in a change in the ratio of stearic
to oleic acid. A similar but less pronounced effect was also observed
with palmitic acid and palmitoleic acid. The liver triglycerides of trout fed CPFA for an extended period also contained less 22:6w3 than
normal. When these fish were fed a CPFA-free control diet their
liver lipids returned to normal within 30 days. / Graduation date: 1968

Identiferoai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/26809
Date09 February 1968
CreatorsRoehm, Jeffrey Noyes
ContributorsSinnhuber, Russell O.
Source SetsOregon State University
Languageen_US
Detected LanguageEnglish
TypeThesis/Dissertation

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