Cent Corn Oil Research Articles

Preparation and properties of a stable intravenous lorazepam emulsion.

Lorazepam is normally administered as a solution in organic solvents such as propylene glycol. This type of formulation is undesirable. This study describes the development of a parenteral emulsion formulation for lorazepam. The stability of lorazepam in the emulsion was examined. Ten per cent corn oil emulsions stabilized with egg lecithin, Pluronic F68 and Pluronic F88 were used. The incorporation of lorazepam does not appear to destabilize the emulsion, and lorazepam itself appears to be stable for at least 1 year in this liquid formulation. Haemolysis caused by emulsion formulations containing lorazepam and different emulsifiers was evaluated using human and rabbit blood to assess their safety as parenteral drug carriers. The results show that the emulsions did not have any significant haemolytic activity whereas organic solvents and solutions of lorazepam in organic solvents caused substantial haemolysis.

In-vivo incorporation of ω3 fatty acids into membrane lipids of rat salivary glands and changes in adenylate-cyclase activity

Dietary ω3 fatty acids from menhaden oil were incorporated into membrane phospholipids of submandibular salivary glands (SMSG). Eicosapentaenoic (20:5), docosapentaenoic (22:5) and docosahexaenoic (22:6) acids constituted about 20 per cent of the total fatty acids in phospholipids, phosphatidylcholine and phosphatidylethanolamine fractions of the SMSG plasma membranes of rats fed for 6 weeks a diet containing 10 per cent menhaden oil. The changes in fatty-acid composition of the membrane phospholipids were accompanied by higher adenylate-cyclase activity in the SMSG membranes of rats fed 10 per cent menhaden oil than in rats fed 10 per cent corn oil or 8 per cent coconut oil + 2 per cent corr oil. However, there were no diet-related differences in the fold-stimulation of adenylatecyclase activity.

Effect of feeding different levels of corn oil on the composition of submandibular salivary gland fatty acids in rats

Male, weanling rats were fed synthetic diets containing 0, 3, 10 and 20 per cent corn oil. Rats were killed after 3 weeks, their plasma and submandibular salivary glands were extracted for lipids, and the fatty acid composition was determined. There were significant changes in the fatty acid composition of both plasma and submandibular salivary glands as a result of feeding different levels of corn oil in the diet. The proportions of monoenoic fatty acids (16:1, 18:1) decreased whereas those of linoleic acid increased as the level of corn oil was increased from 0 to 20 per cent. Arachidonic acid level was the lowest in the fat-free group as compared with the other groups. Plasma and submandibular salivary gland lipids of rats fed 0 per cent corn oil in their diet contained another fatty acid which appears to be eicosadicnoic fatty acid. The changes in submandibular salivary gland fatty acids were correlated with the changes in plasma fatty acids. Fractions of neutral lipids and phospholipids which were isolated from the submandibular salivary glands showed changes in their fatty acid composition similar to those observed in the total lipid extract.

Effect of essential fatty acid deficiency on the fatty acid composition of individual lipids from enamel and dentine of the rat

Neutral lipids and phospholipids were extracted from enamel and dentine of incisors and molars from rats maintained on a high-sugar synthetic diet containing 5 per cent corn oil as a source of essential fatty acids, and from rats maintained on a high-sugar synthetic diet deficient in essential fatty acids. The fatty acids of the individual lipids were analysed qualitatively and quantitatively, the overall effect of essential fatty acid deficiency being that the proportion of longer chain fatty acids increased in all the lipid classes with. in particular, the appearance of a high proportion of docosahexaenoic acid (C 22:6) in the phosphatidyl ethanolamine and phosphatidic acid plus cardiolipin fraction from both enamel and dentine.

The effect on the lipid composition of enamel and dentine of feeding a corn oil supplement to rats deficient in essential fatty acids

Rats which had been made deficient in essential fatty acids (EFA) by feeding a deficient diet were then fed a diet containing 5.0 per cent corn oil as a source of EFA. Subsequently lipids were extracted from enamel and dentine before and after decalcification and analysed quantitatively and qualitatively. The analyses indicate that the lipid composition of the tissues was intermediate between that found when rats were maintained on a diet deficient in or containing EFA from weaning. It is considered that the changes produced in teeth by EFA deficiency are reversible.

Distribution of dietary elaidic acid in subcellular particles of rat liver

1. 1. Male rats divided into four groups were fed a 20 per cent partially hydrogenated soybean fat, this diet supplemented with 2 per cent corn oil, a fat-free diet, and a regular diet. 2. 2. The fatty acid composition of each lipid class and phospholipid subclass from microsomes, mitochondria, supernatant, fluffy layer, and whole liver was determined. 3. 3. Elaidate incorporated to varying proportions in each of the lipid classes. Triglyceride and cholesterol esters were the richest fractions in elaidate, whereas cardiolipin contained very little of this acid. 4. 4. The fatty acid patterns displayed by triglycerides and phospholipids were the same in all subcellular fractions and in whole liver, whereas cholesterol esters exhibited different fatty acid patterns. 5. 5. Inclusion of dietary linoleic acid into the hydrogenated fat diet facilitated incorporation of elaidic acid in adipose tissue and liver neutral lipids. Its absence from that diet augmented the accumulation of eicosadienoic acids in microsomal and mitochondrial lipids.

Dietary fatty acid-induced alterations of hepatic microsomal drug metabolism

Male and female weanling, Sprague-Dawley rats were fed synthetic fat-free (FF) or corn oil-containing diets for 3 weeks. The apparent K m and V max for the metabolism of ethylmorphine and hexobarbital were lower in washed hepatic microsomes from male rats fed a FF diet than in rats fed diets containing 3 or 10 per cent corn oil. The apparent V max for aniline hydroxylase was also depressed by feeding a FF diet to male rats, although aniline K m was not altered. Feeding a FF diet to female rats decreased V max for both hexobarbital oxidase and aniline hydroxylase, but the apparent K m for the substrates was not changed. Gas-liquid Chromatographie analysis of fatty acids derived from microsomal membranes revealed marked alterations in the relative content of fatty acids in response to FF feeding. Content of cytochrome P-450 was lower in both male and female rats fed a FF diet. Associated with the decreased cytochrome P-450 content were decreases in the ability of microsomes to bind aniline and hexobarbital. A qualitative change produced in cytochrome P-450 was indicated by a decrease in the ratio of ethyl isocyanide peak heights (455:430 nm) in microsomes from FF-fed rats.

Short-term adaptation of pancreatic hydrolases to nutritional and physiological stimuli in adult rats

Abstract o 1. Adult rats, previously maintained on a chow containing 48 p. cent carbohydrates, were fasted 24 h, then refed for 5 days on various diets. The nutritional stimuli were made up either of 4 p. cent corn oil, 67 p. cent of a carbohydrate, and 18 p. cent casein, or of 50 p. cent lipid, 0 p. cent carbohydrates and 18 p. cent casein (w:w). Other rats were simply starved for 3 or 6 days, and a group was diabetic after 7 days on chow, following alloxan administration. 2. The opposite regulations of α-amylase and lipase were striking. The specific activities of both hydrolases tripled within 5 days in the presence of their best inducers (starch and corn oil respectively). The specific activity of the second enzyme decreased simultaneously to one third of its initial value. These variations were reversible. 3. The specific activity of amylase on 67 p. cent starch, glucose, fructose or sucrose did not exceed that on the 48 p. cent carbohydrate chow. The induction by galactose and lactose was mediocre. Amylase decreased sharply during fasting and in diabetic rats. The enzyme was always depressed on fat-diets, but somewhat less so on tricaprylin. 4. When compared to control values on chow, several circumstances favored lipase induction. The specific activity of lipase in the pancreas doubled in diabetic rats. The increase on 67 p. cent galactose was probably due to reduced glucose tolerance. Diets rich in starch, fructose and sucrose also increased lipase. All 50 p. cent fat diets stimulated lipase. Triolein, and various oils (olive, corn, sunflower, walnut and lineseed oils) yielded results twice as good as those with more saturated fats (tricaprylin, tristearin and lard). 5. The activities estimated in the small intestine partially reflected inductions.

The effect of dietary fat load on the size and composition of chylomicrons in thoracic duct lymph.

Chylomicrons of Sf 〉 400 and lipoproteins of Sf 12‐400 were separated by ultra‐centrifugation from samples of thoracic duct lymph collected from rabbits fed for 1 to 2 weeks previously on diets containing 5 per cent and 30 per cent corn oil or butter and from rats given a single intragastric dose of 0·5 ml. corn oil.The size of these particles after corn oil was determined by electron microscopy following fixation in osmium tetroxide. In rabbits on the low fat diet the mean diameter of chylomicrons was 960 Å with half the triglyceride in particles of diameter greater than 1400 Å; on the high fat diet the mean diameter was 1435 Å with half the triglyceride in particles of diameter greater than 2700 Å. In rats the mean chylomicron diameter was 1094 Å in the early phase of fat absorption with half the triglyceride in particles of diameter greater than 1320 Å. These figures increased to 2105 Å and 3600 Å respectively at the peak of fat absorption.The relationship between the chemical composition of these complexes and their actual size suggests that phospholipid is uniformly distributed on the surface, each phospholipid molecule occupying approximately 65 Å2.Although meaningful electron micrographs of butter chylomicrons could not be obtained, determinations of the triglyceride : phospholipid ratios indicate that, as with the corn oil‐fed animals, the chylomicrons from the rabbits fed 30 per cent butter are on the average larger than those from the animals fed 5 per cent butter.

The Effect of Various Types of Fat on the Cholesterol Distribution in the Rat

AbstractExperiments were conducted with and without addition of 1 per cent cholesterol to diets containing 20 per cent of fats of the following types: 1. corn oil, 2. 19.5 per cent hydrogenated coconut oil and 0.5 per cent corn oil, and 3. 12 per cent hydrogenated coconut oil and 8 per cent olive oil. Following a 3 weeks' pre‐experimental period on a fat free diet adult female rats were given the experimental diets for 6 weeks. In rats given cholesterol corn oil caused the well known transfer of cholesterol from plasma to the liver. In rats given diets containing cholesterol and corn oil the cholesterol content of the liver was considerably higher and serum cholesterol much lower in rats given the diet containing olive oil. The result indicate that linoleic acid probably enhances cholesterol absorption over and above the effect of oleic acid. The carcass cholesterol of rats given corn oil was slightly lower than in rats given type 2 of fat. The difference was statistically significant on cholesterol free diets. When various tissues were analysed corn oil induced transfer to other tissues than the liver could not be observed.

The effect of diet and thyroxin on plasma lipids in myxedema

Four patients with primary hypothyroidism have been studied on high fat and low fat formula diets before and after treatment with thyroxin. Diet had a marked effect on plasma lipid levels in myxedema that was proportionately similar to the effect in the treated state. Fasting plasma turbidity, usually without gross lactescence, was found in the subjects on 40 per cent corn oil diets. Thyroid hormone deficiency appeared to affect the entire lipoprotein spectrum, causing hypertriglyceridemia as well as hypercholesterolemia. Therefore, myxedema appears to represent an altered dynamic steady state of elevated lipoprotein concentrations in which diet has a significant effect.

Effect of the Saturation of Fats Upon the Disposition of Ingested Cholesterol

Rats were fed diets containing 30 per cent corn oil or lard with and without cholesterol and choline for four weeks. An attempt was made to learn more about the mechanism involved in changes in the blood cholesterol level associated with such diets by comparing the total amoung of sterol ingested with the recovered from the carcass tissues, fecal sterols and bile acids. Similar recoveries of activities were attempted in another group of animals given cholesterol-4-C14 after three weeks on similar diets. Sterol levels were found to be higher in the blood and carcass tissues of all animals on diets containing excessive amounts of cholesterol, even though only a limited amount of it appeared to be absorbed. The blood sterol level was elevated when dietary lard replaced the corn oil, whereas the tissue content appeared to be slightly increased by the intake of the more unsaturated fat. The amount of fecal sterols and bile acids or activity excreted by the rats on the corn oil and lard-containing diets was similar whereas in those on the low fat diet more activity was retained in the blood and carcasses and less was excreted. Lack of major changes in the disposition of ingested sterol in rats on the high fat diets prevents any definitite conclusions as to their role in the mechanism involved in blood cholesterol changes. The mass of conflicting reports attests to the increasing belief that this problem cannot be resolved without a more basic approach, probably at the cellular or subcellular level. However, the data obtained in this investigation and in many others are quite in line with the suggestion that the major changes in the blood cholesterol level may be caused by the ingested saturated fat rather than the unsaturated fat.

Effect of vitamin D, sucrose, corn oil and endocrines on tissue cholesterol in rats.

A diet containing 65 per cent sucrose with added cholesterol resulted in hypercholesteremia and increased tissue cholesterol deposition in rats. Ten per cent corn oil with added cholesterol in Purina laboratory chow had no apparent effect on the serum total cholesterol but increased cholesterol deposition in tissues. Ovariectomy was without significant effect. Thyroidectomy or hypophysectomy aggravated the hypercholesteremia and the increased tissue cholesterol deposition induced by the sucrose diet. The effect of hypophysectomy was not due to the loss of thyrotrophic hormone alone. Addition of vitamin D aggravated hypercholesteremia and increased liver cholesterol deposition in normal, thyroidectomized or hypophysectomized rats fed the sucrose diet. In ovariectomized rats, the tissue cholesterol deposition was also augmented. When corn oil diet was fed, the supplementary vitamin D increased the serum total cholesterol level of the thyroidectomized rat.

INFLUENCE OF DIETARY FAT ON ENERGY CONSUMPTION AND DIGESTION AND ON NITROGEN UTILIZATION OF WEANLING RATS

Energy digestibility and nitrogen retention were determined with weanling albino rats of the Sprague-Dawley strain fed diets varying from 0 to 30 per cent corn oil and containing 3 ratios of Cal. apparent digestible energy per gm. apparent digestible nitrogen at each fat level. Vitamins, salts and pure linoleic acid were included in the diets at calculated constant levels relative to the apparent digestible energy content. A 7-day metabolism, period followed a 7-day diet acclimatization period. Food consumption varied inversely with the digestible energy content of the diet so that intake of digestible Cal. remained essentially constant and gain in weight of the rats was similar at all fat levels. Nitrogen levels per se did not influence digestible energy consumption but an interaction existed between fat × nitrogen levels in the diet in relation to digestible energy intake. Efficiency of food utilization improved as either fat or nitrogen levels in the diet increased. Energy digestibility was decreased slightly by the addition of fat to a fat-free diet when allowance was made for the influence of non-nutritive cellulose levels in the diets. The addition of fat to the diet resulted in a significant improvement in nitrogen digestibility and gross nitrogen retention.