Dietary Cottonseed Oil Research Articles

The effect of dietary fat on the activity, content, rates of synthesis, and degradation and translation of messenger RNA coding for malic enzyme in mouse liver

The specific activity (units activity/mg cytosolic protein) of malic enzyme was found to be three-fold higher in the livers of mice fed a semipurified diet containing 50% ( w w ) glucose and 15% ( w w ) saturated and monounsaturated but no polyunsaturated fat (hydrogenated cottonseed oil) over an 11-day period than in the livers of mice fed a standard laboratory mouse chow (Purina) diet. In contrast, when other lab chow-fed mice were fed an isocaloric diet containing 15% ( w w ) polyunsaturated fat (corn oil), no change in the specific activity of malic enzyme occurred over a similar period of time. Rocket immunoelectrophoresis performed on cytosols from both dietary groups demonstrated that the livers of mice consuming the hydrogenated cottonseed oil diet contained approximately three times more malic enzyme protein than did the livers from the corn oil-fed animals. In mice pulse-labeled with l-[4,5- 3H]leucine, the rate of hepatic malic enzyme synthesis (relative to that for total protein) was approximately twofold greater in the hydrogenated cottonseed oil-fed mice than in their corn oil-fed counterparts whereas the rate of hepatic malic enzyme degradation was similar for both groups. Immunotitration of liver malic enzyme from hydrogenated cottonseed oil-fed and corn oil-fed mice revealed identical equivalence points, demonstrating that the catalytic efficiency of mouse liver malic enzyme had not been affected by the type of dietary fat administered. When total liver RNA, isolated from the hydrogenated cottonseed oil- and the corn oil-fed animals, was translated in cell-free translation systems (wheat germ extract and reticulocyte lysate) we found that both dietary treatments had resulted in an increase in the activity of malic enzyme messenger RNA. Furthermore, there were no significant differences between the two dietary groups in this regard. These results suggest that hepatic malic enzyme specific activity in high-carbohydrate polyunsaturated fat-fed mice is regulated principally by dietary-induced changes in the rate of enzyme synthesis and not by the activity of messenger RNA coding for the enzyme.

Regulation of mouse hepatic ATP-citrate lyase activity by dietary fat evidence for the presence of inactive enzyme

The induction of ATP-citrate lyase activity in mouse liver by dietary carbohydrate (glucose) is markedly reduced by including in the diet a source of polyunsaturated fatty acids. Within 72 h after changing from a standard mouse chow diet to a high carbohydrate diet containing 15% (w/w) of hydrogenated cottonseed oil (as a source of saturated fatty acids), the activity of mouse liver ATP-citrate lyase per milligram cytosolic protein was approx. 3-fold higher than that from mice fed a similar diet containing 15% (w/w) of corn oil. The rate of synthesis of ATP-citrate lyase relative to that for total protein and the rate of degradation of the enzyme were similar for both dietary groups. Elevated levels of enzyme activity in the hydrogenated cottonseed oil-fed livers were not accompanied by a similar increase in the amount of enzyme protein. To explain such findings, we propose that the activity of hepatic ATP-citrate lyase is regulated by dietary polyunsaturated fatty acids through a mechanism involving the conversion of a catalytically active form of the enzyme to a catalytically inactive form. A reversal of this conversion (inactive-active)_is evident within 72 h of removing the mice from the corn oil diet and placing them on the hydrogenated cottonseed oil diet. Futhermore, the conversion appears to be independent of the in vivo rate of synthesis of the enzyme.

Further studies on the effects of dietary cottonseed oil on milk-fat secretion in the cow

SummaryThe effects of the isocaloric replacement of part of the dietary concentrate mixture by cottonseed oil on the yield and composition of the milk fat and on the pattern of rumen fermentation was investigated in 2 feeding experiments with a total of 8 cows in mid-lactation. The concentrate mixtures were given with high- or low-roughage diets that supplied 9·1 or 1·8 kg of hay/day.In expt 1 the yield of milk fat was not altered by the addition of 10% cottonseed oil to the concentrate mixtures given either with the high- or with the low-levels of dietary roughage. On the low-roughage treatment, dietary cottonseed oil increased milk yield but reduced the fat content of the milk. The change from the high- to the low-roughage diets containing no cottonseed oil resulted in reductions in the yield and percentage of fat in the milk. In expt 2 the yields of milk and milk fat were similar irrespective of whether the concentrate mixture contained 5 or 10% cottonseed oil.In expt 1 the inclusion of 10% cottonseed oil in the concentrate mixture reduced the yields and percentages of the medium-chain fatty acids (12:0, 14:0 and 16:0) and increased the yields and percentages of the C18 fatty acids in the milk fat. In expt 2, when the concentrate mixture contained 5% cottonseed oil, the yields and percentages of all the fatty acids in the milk fat were similar to the values obtained when the concentrates contained 10% cottonseed oil. For any given concentrate mixture, the change from the high- to the low-roughage treatments in both expts 1 and 2 resulted in increases in the percentage of oleic acid in the milk fat. The highest concentration of trans-octadecenoic acid was observed in the milk fat of the cows when they were given the high-roughage diet with the concentrate mixture containing 10% cottonseed oil.In expt 2 the level of cottonseed oil in the concentrate mixture did not influence the pattern of rumen fermentation as measured by the concentrations of the various volatile fatty acids in the rumen liquor. However, the change from the high- to the low-roughage diets reduced the proportion of acetic and increased the proportions of propionic and n-valeric acids in the total volatile fatty acids in the rumen liquor.

Effects of Dietary Fat Level on Pantothenate Depletion and Liver Fatty Acid Composition in the Rat

Weanling male rats were fed a 6% or an 18% cottonseed oil diet, lacking pantothenate or supplemented with graded levels of pantothenate, to determine whether a high fat diet would accelerate the development of pantothenate deficiency or increase the pantothenate requirement for growth. The fatty acid composition of liver lipid fractions was also determined. Increasing the level of fat did not increase the pantothenate requirement for maximal growth or accelerate the development of the deficiency as indicated by body weight, adrenal weight, or onset and incidence of greying. Pantothenate deficiency with either the 6% fat or the 18% fat diet significantly lowered the relative proportions of phospholipid arachidonate and stearate. Liver CoA values in both the control and deficient groups fed the 18% fat diet were significantly lower than in the rats fed the 6% fat diet.

The influence of dietary fatty acids and environmental temperature on the fatty acid composition of teleost fish

AbstractMarine and fresh water fish were depleted of tissue unsaturated fatty acids to various degrees and subsequently presented with linoleic and linolenic acids at different dietary levels, at different temperatures, with and without other dietary fat.Examination of the tissue fatty acids demonstrated that marine and fresh water fish do not differ between themselves or from other classes of animals in the following basic mechanisms of deposition and interconversions of dietary fatty acids: The fish are readily depleted of tissue polyunsaturated fatty acids. Dietary linoleic and linolenic acids are deposited, the former to a greater degree than the latter. At high levels of linoleic or linolenic acids in the diet there is no significant degree of their conversion to the longer chain more highly unsaturated acids typical of marine oils. At low levels of linoleic or linolenic acids in the tissues there is a significant, but slight, conversion to the longer chain acids at low environmental temperatures. The increase in the level of linoleic acid in tissue lipids which accompanies increases in the dietary levels, quickly tapers off above dietary levels of 5%. Temperature differences between 13 and 23C had little or no influence on the deposition or interconversion of polyunsaturated acids. Dietary cottonseed oil, which contains cyclopropene fatty acids, produces an increase in tissue stearic acid in the fundulus.

Vitamin B6 and Cholesterol Metabolism in the Chick

CONSIDERABLE evidence has been presented during the past few years indicating that vitamin B6 is involved in various aspects of lipid metabolism, particularly in the metabolism of cholesterol and the essential fatty acids.The first indication of a possible relationship between vitamin B6 and lipid metabolism was presented by Birch and Gyorgy (1936), who observed that highly unsaturated fat alleviated cutaneous manifestations of vitamin B6 deficiency in the rat. Since then, several studies have shown that the feeding of fat ameliorates the development of vitamin B6 deficiency. Williams and Cohen (1957) demonstrated that levels of dietary cottonseed or coconut oil above 5% had no effect on the development of vitamin B6 deficiency in male weanling rats in a period of three weeks when the protein to energy ratio was constant. When the ratio was decreased, the 40 percent cottonseed oil diet permitted slightly better growth, but the difference was not …

Serum and Liver Cholesterol, Total Lipids and Lipid Phosphorus Levels of Rats under Various Dietary Regimens

S TUDIES mnade at this university on the effect of different kinds and levels of fats on the excretion of urinary metabolites of rats and later of man focused our interest on what was happening to the serum and liver cholesterol values of the subjects. Of the nutritional factors which may affect the level of cholesterol in blood, the kind and level of dietary fat has been under intensive study in a number of laboratories. Recent studies involving fats alone or in combination with other factors have been reported. Okey and Lyman’ found that serum cholesterol values of rats fed 10 jer cent coconut oil tended to be higher than those of rats fed partly hardened cottonseed oil. Liver cholesterol storage was greatest on the cottonseed oil diets. When Aftergood et al.2 used 15 per cent lard and 15 per cent cottonseed oil, they found that feeding the lard diets resulted in higher liver and serum cholesterol values when the diet contained cholesterol.

The effect of diet on the fatty acid composition of several species of fresh water fish

SummaryFour kinds of fresh water fish were captured in the young stage, maintained on a low‐fat diet for about two months, and either continued on that diet or transferred to test diets containing 10% cottonseed or menhaden oil for about five weeks. The fish were then sacrificed, and their total body fatty acids were examined for relative amounts of 2, 3, 4, 5 and 6 double bonds. It was found that no significant change from the natural diet occurred in the fatty acids on the low‐fat or cottonseed oil diets while on the menhaden oil diet the fatty acid composition changed to resemble the composition of that oil.These changes differed from those of the marine mullet in that the body fat of the latter lost much of its naturally occurring polyunsaturated acids, when placed on the low‐fat regimen, and regained it on the menhaden oil diet.

Dietary Fat in the Nutrition of the Growing Chick

SUPPLEMENTAL fat in the diet of the growing chick has been shown to have deleterious effects in some cases and beneficial effects in others. Henderson and Irwin (1940) reported that soybean oil was detrimental to chick growth when added at levels higher than 10 percent. Fraps (1943) also showed that the growth rate of chicks was markedly depressed as the level of dietary cottonseed oil was raised from 10 to 30 percent. Kummerow et al. (1949) reported that 25 percent linseed oil depressed growth and increased the incidence of perosis in chicks. Reiser and Pearson (1949) reported that the addition of cottonseed oil to a riboflavin deficient diet accentuated the effects of riboflavin deficiency in the chick. Yacowitz (1953) reported that while 2½ to 5 percent of supplemental fat improved growth, higher levels (10 to 15 percent) exerted an adverse influence on growth and feathering. March and Biely (1954) and . . .

Effect of the level and type of dietary fat on the metabolism of cholesterol and beta lipoproteins in the Cebus monkey.

A study was carried out to determine the effect of the level and type of dietary fat on the concentration of cholesterol and beta lipoproteins in the sera of Cebus monkeys. Three groups of monkeys were fed isocaloric diets containing a fixed ratio of alpha protein and cholesterol to calories but with different amounts of corn oil and sucrose. Corn oil provided 10, 32, and 45 per cent of the calories in the three diets, and the level of sucrose was varied inversely. After 8 weeks the serum cholesterol and S(f) 12 to 100 beta lipoprotein concentrations were significantly greater in the medium and high fat groups. When corn oil was decreased from 45 to 10 per cent of dietary calories and sucrose was increased, the serum cholesterol fell in all cases, and when the reverse change was made, the concentration of serum cholesterol increased. Variation in dietary sucrose had no specific effect. Substitution of starch for sucrose with diets otherwise constant did not cause significant change in the concentration of serum cholesterol. When monkeys fed corn oil diets at any of three levels were changed to hydrogenated cottonseed oil diets at the same level, the serum cholesterol and S(f) 12 to 100 beta lipoproteins rose. However, hydrogenated cottonseed oil had no greater hypercholesteremic effect than did corn oil in the absence of dietary cholesterol. Diets containing lard with cholesterol also produced strikingly greater serum lipide responses than did diets based on corn oil and cholesterol. Hydrogenated cottonseed oil had a greater hypercholesteremic effect than an unhydrogenated cottonseed oil from the same lot. Preliminary studies indicated that the saturated fats (hydrogenated cottonseed oil) produced the most striking elevation of serum cholesterol values (above controls fed corn oil) when casein was the dietary protein.

The Effect of Fat Level of the Diet on General Nutrition VI. The Interrelation of Linoleate and Linolenate in Supplying the Essential Fatty Acid Requirement in the Rat ,

A sex difference in the requirement for linoleic acid has been found. The optimum dosage for male rats exceeds 50 mg daily, while that for female rats has been found to be between 10 and 20 mg per day. The requirement for male rats based on extrapolation data would appear to be 100 mg daily. Linolenic acid had only slight growth-promoting action when fed alone to fat-depleted rats at the level indicated. However, when fed with suboptimum doses of linoleic acid, the resultant activity of the additional linolenate equalled that of linoleate. It is suggested that a sparking action on the part of linoleate is required before linolenate can play its role as an essential acid. Greater growth was found in the female rats on 30% cotton-seed oil diets than could be obtained on a fat-low regime where the animals were supplemented with an optimum quantity of methyl linoleate. In the case of male rats, it would appear probable that the growth of animals on a fat-free regime might be raised to that of rats on a 30% fat diet if a sufficiently high amount of methyl linoleate were administered. The growth response of the male rats plotted against the log dose was a straight line function when linoleate in the range of 5 to 50 mg was administered. The possibility of using such a procedure for assay of the biopotency of substances containing essential fatty acids is discussed.