摘要:

Mice were fed diets containing a constant supply of linoleic acid (18:2n-6, LA) as ethyl ester representing 5% by weight of the total fat (5 wt%), in combination with graded amounts of purified docosahexaenoate (22:6n-3, DHA). Cardiac sarcoplasmic reticulum (SR) and mitochondrial phospholipids (PL) from mice fed the diet without DHA contained higher levels of n-6 long chain polyunsaturated fatty acids (PUFA) (22:4n-6 and 22:5n-6) compared to total PL of liver. In the cardiac mitochondrial PL, the level of LA, DHA, the total content of PUFA and the P/S ratio were significantly higher than in SR. A small increase in dietary DHA from 0 to 0.43 wt% induced a 3.6-fold increase in PL DHA content from both cardiac organelles, with a concurrent reduction of n-6 PUFA. The changes in fatty acid PL composition were much more moderate when dietary DHA level was increased to 0.85 and 3.74 wt%. Feeding the lowest amount of DHA resulted in a 6-fold decrease in the value of n-6/n-3 PUFA ratio and a 3.5-fold decrease in the value of 20 carbon chain/22 carbon chain PUFA ratio. DHA was readily depleted from cardiac PL, and only arachidonic acid was retained in the PL from both organelles, after feeding a fat-deficient diet. Despite these drastic modifications in PL fatty acid composition, the maximum velocity (Vm) of SR Ca2+, Mg2+-ATPase was not affected, which indicates that SR cardiac membrane adapts to changes in fatty acid composition to prevent important modifications of its functional properties. However, the Vm of mitochondrial oligomycin-sensitive ATPase was slightly increased in mice fed the lowest amount of DHA. This might be due to an increase in P/S ratio and/or to a modification of cardiolipin fatty acid composition, since this PL is required for optimum function of this enzyme. It is concluded that DHA is strongly taken up by mouse cardiac PL, even in the presence of high dietary LA levels, but its acylation into PL has only little effect on the cardiac ATPase activities.

ISSN:0250-6807    

DOI:10.1159/000177530

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Experiments were conducted to determine the effects of dietary supplements of amino acid precursors of polyamines on amino acid metabolism in the rat in order to better understand comparative aspects of polyamine metabolism. Rats were fed isonitrogenous combinations of methionine, ornithine, arginine and 2-difluoromethylornithine in casein-based diets. It was observed that hepatic concentrations of methionine, 5’-deoxy-5’-methylthioadenosine and decarboxylated S-adenosylmethionine were more easily influenced by diet than were arginine and metabolites. It was concluded that rats may be more refractory to exogenous polyamine precursor amino acids than are chicks because of the presence of a functional urea cy

ISSN:0250-6807    

DOI:10.1159/000177531

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Tocopherol, one of the antioxidants in vegetable fats and oils, was added to the autoxidized diet of male rats at the same tocopherol level as soybean oil before autoxidation. Autoxidized soybean oil was used as the test lipid; fresh soybean oil was the control. The diet containing autoxidized oil depressed the body weight gains and increased the tissue ratios to body weight, with the exception of testicle. Parallel with those, increased hemolysis, peroxide value and carbonyl value in the tissue lipids, and a decrease in linoleic or arachidonic acid was observed. The effect of dietary vitamin E on the tissue lipid peroxidation was different among the individual organs. From the results obtained by chemical analyses, the lipid peroxidation caused in the liver, heart and intestine was recognized to be suppressed effectively when the same tocopherol level as fresh soybean oil was added to the diet.

ISSN:0250-6807    

DOI:10.1159/000177532

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

Carnitine, biosynthesized from the essential amino acid lysine, has been considered as the shuttling of long-chain fatty acid acyl residues into the matrix of mitochrondria for β-oxidation. This lysine-carnitine relation was studied in pregnant rats nourished with diets differing in lysine and protein content. Pregnancy seems to be a factor contributing to the increase of the free carnitine fraction and phospholipids in the liver, whatever the diet allowed. In the case of nonpregnant rats, free carnitine levels decrease and triglycerides increase in the liver when they are nourished with a low-protein and lysine-deficient diet

ISSN:0250-6807    

DOI:10.1159/000177533

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

The effects of dietary cholesterol and fats on cholesterol metabolism later in life were studied in Mongolian gerbils. Three groups were given a basic diet with soybean oil, palm kernel oil amounting to 8.75% (w/w), or the basic diet only. In three other groups, cholesterol (0.05 %) was added to the above diets. Measurements were done in animals of the third generation on the diets. On all diets, the serum cholesterol of the sucklings was increased as compared to the young that were suckled by mothers on the basic diet only, while body cholesterol was highest in sucklings of mothers on the basic diet or palm-kernel-oil-enriched diets. When the diets were replaced by the basic diets at 6 months of age, serum cholesterol was still increased at 12 months of age in animals previously fed on the cholesterol-enriched diets. Tissue cholesterol did not differ. However, after a challenge with cholesterol at that age, the differences in serum cholesterol were not significantly different.

ISSN:0250-6807    

DOI:10.1159/000177534

出版商:S. Karger AG    

年代:1989

数据来源: Karger

摘要:

In order to evaluate some factors likely to be involved in the maternal and fetal growth impairment due to alimentary protein deficiency, the circulating levels of triiodothyronine (T3) and thyroxine (T4) were studied in 4 young (45-day-old) female rat groups: control and malnourished, both nonpregnant and pregnant; similarly scheduled groups were studied using adult (100-day-old) rats. Circulating levels of T4 were higher in nonpregnant, malnourished young rats than in their corresponding controls. T3 levels were higher in young malnourished animals and lower in adult malnourished animals, nonpregnant or pregnant, as compared to controls. Pups from young malnourished mothers showed significantly lower birth weights than those from controls. The present results suggest that there are age differences in thyroid function, as affected by protein-calorie malnutrition in pregnant and nonpregnant rats. On the other hand, the circulating thyroid hormone levels were not importantly affected by the mother dietary protein restriction under our experimental conditions.

ISSN:0250-6807    

DOI:10.1159/000177535

出版商:S. Karger AG    

年代:1989

数据来源: Karger

ISSN:0250-6807    

DOI:10.1159/000177536

出版商:S. Karger AG    

年代:1989

数据来源: Karger