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• 1. [Article] 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 ...

  Citation × Citation Citation Abstract Copy Title: Changes in the lipid composition of rainbow trout (Salmo gairdnerii) fed cyclopropenoid fatty acids Author: Roehm, Jeffrey Noyes 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. Title: Changes in the lipid composition of rainbow trout (Salmo gairdnerii) fed cyclopropenoid fatty acids Author: Roehm, Jeffrey Noyes 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. Close

• 2. [Article] Effect of cyclopropenoid fatty acids on membrane components of liver of rainbow trout (Salmo gairdneri)

  Three studies were conducted to determine the effects of cyclopropenoid fatty acids (CPFA) on the membrane components of livers of rainbow trout (Salmo gairdneri). In the first study, ¹⁴C-sterculic acid ...

  Citation × Citation Citation Abstract Copy Title: Effect of cyclopropenoid fatty acids on membrane components of liver of rainbow trout (Salmo gairdneri) Author: Einerson, Mark A. Three studies were conducted to determine the effects of cyclopropenoid fatty acids (CPFA) on the membrane components of livers of rainbow trout (Salmo gairdneri). In the first study, ¹⁴C-sterculic acid was administered by intraperitoneal injection into rainbow trout and the trout maintained for 72 hours. The labelled sterculic acid was found in choline phospholipids (CP) and ethanolamine phospholipids (EP). Smaller amounts of label were found in other microsomal membrane lipid components. No label was found associated with the proteins of the microsomal membrane. Phospholipase A₂ treatment of isolated CP and EP showed ¹⁴C-sterculic acid to be preferentially esterified to the 1-position of the glycerol backbone. In the second study, the cleavable bifunctional protein crosslinking reagent dimethyl 3,3'-dithiobispropionimidate-2HCl (DTBP) was used in an attempt to study alterations in the spatial arrangement of proteins in liver microsomal and plasma membranes that might be induced by dietary CPFA. The use of this reagent failed to yield a clear picture of protein-protein interactions in the microsomal membrane due to the formation of high molecular weight aggregates that were not resolvable on polyacrylamide gels. On the other hand, the use of DTBP failed to crosslink the proteins of the plasma membrane. In the third study, two-dimensional polyacrylamide gel electrophoresis was used to assess the effects of dietary CPFA on protein composition of trout liver microsomal and plasma membranes. Proteins were separated in the first dimension on the basis of their isoelectric points and in the second dimension on the basis of their molecular weights. No major alterations in the composition of liver microsomal or plasma membranes were found to be induced by dietary CPFA. Title: Effect of cyclopropenoid fatty acids on membrane components of liver of rainbow trout (Salmo gairdneri) Author: Einerson, Mark A. Three studies were conducted to determine the effects of cyclopropenoid fatty acids (CPFA) on the membrane components of livers of rainbow trout (Salmo gairdneri). In the first study, ¹⁴C-sterculic acid was administered by intraperitoneal injection into rainbow trout and the trout maintained for 72 hours. The labelled sterculic acid was found in choline phospholipids (CP) and ethanolamine phospholipids (EP). Smaller amounts of label were found in other microsomal membrane lipid components. No label was found associated with the proteins of the microsomal membrane. Phospholipase A₂ treatment of isolated CP and EP showed ¹⁴C-sterculic acid to be preferentially esterified to the 1-position of the glycerol backbone. In the second study, the cleavable bifunctional protein crosslinking reagent dimethyl 3,3'-dithiobispropionimidate-2HCl (DTBP) was used in an attempt to study alterations in the spatial arrangement of proteins in liver microsomal and plasma membranes that might be induced by dietary CPFA. The use of this reagent failed to yield a clear picture of protein-protein interactions in the microsomal membrane due to the formation of high molecular weight aggregates that were not resolvable on polyacrylamide gels. On the other hand, the use of DTBP failed to crosslink the proteins of the plasma membrane. In the third study, two-dimensional polyacrylamide gel electrophoresis was used to assess the effects of dietary CPFA on protein composition of trout liver microsomal and plasma membranes. Proteins were separated in the first dimension on the basis of their isoelectric points and in the second dimension on the basis of their molecular weights. No major alterations in the composition of liver microsomal or plasma membranes were found to be induced by dietary CPFA. Close