Normal Stock Diet Research Articles

Hypoglycemic and Hypolipidemic effects of Watermelon (Citrullus vulgaris) Seed Kernels on Male Albino Rats

The current investigation was planned to assess the hypoglycemic and hypolipidemic efficiency of watermelon seeds on male albino rats. Eight male albino rats weighing between 105-150g were randomly selected for the present experiment and were placed into two equal groups (n=4) designated as control and treated group. The control group received normal stock diet (20% protein, 5 % fat, 60 % carbohydrate). The treated group received a modified diet (90g Stock diet excluding groundnut oil + 9g watermelon seed kernel + 1g sugar). Percentages of protein, fat and carbohydrate in the modified diet were kept same as that of the stock diet. All animals were given water ad libitum. Rats were weighed at weekly intervals. After 28 days rats were anesthetized using chloroform anesthesia and blood samples were collected via cardiac puncture and serum was obtained for evaluation of some biochemical parameters. Result showed that serum glucose, triglyceride (TG) and very low density lipoprotein (VLDL) of the treated group were decreased significantly (p < 0.01, p < 0.05 and p < 0.05 respectively) compared to that of the control group. Liver glycogen, serum total cholesterol, low density lipoprotein (LDL) and AI (Atherogenic Index) were decreased (non-significant) whereas high density lipoprotein (HDL) increased (non-significant) in the treated group.

Nutritional Evaluation of Oleogel Made from Micronutrient Rich Edible Oils.

The present study examined the nutritional properties of trans-free edible oleogels made from oil blends of rice bran and flaxseed in animal model. Oleogels were prepared by using mixture of palm stearin (PS) with cetyl laurate (CL) and palm stearin (PS) with cetyl caprylate (CC) as oleogelators. The oleogel samples were prepared with 15 weight % oleogelators (2:1 molar ratio of PS:CC or PS:CL) at 60°C with 1 hr constant stirring in blended oil. The prepared oleogel samples were subjected to DSC and XRD studies in order to evaluate their melting and crystal characteristics. Oleogel formed by using PS and CC showed the desired thermal characteristics. The peak melting temperature of the said sample was almost 44.5°C as determined by the DSC technique. The X-ray diffraction study clearly signified that the crystals were well developed. For nutritional evaluation, Male Wister rats were fed with prepared oleogel samples along with control diet for 4 weeks. Animals were divided into four groups. The control group was fed with normal stock diet containing blend of rice bran oil and flaxseed oil (4:1); one was fed with TFA rich vanaspati (TFA content is about 11.20%); experimental groups were fed with oleogel prepared by using PS:CC and oleogel prepared by using PS:CL respectively. Analysis of the blood lipid profile of the four groups was done. In vivo study established the cholesterol lowering properties of prepared oleogel samples which further enhanced the novelty of oleogel as healthy alternative of trans fat. The positive changes were more pronounced in case of rats fed with oleogel prepared with PS:CC as oleogelators. This study provides an elegant approach of producing trans-free edible quality oleogel with recognized cholesterol lowering property.

Effect of Vitamin A on Pulmonary Macrophage Mobilization in Hamsters Exposed to Cigarette Smoke.

Male Syrian golden hamsters fed either vitamin A-free diet or normal stock diet with or without vitamin A supplementation were subjected to cigarette smoke inhalation for 6 weeks to study the relationship between the pulmonary cell response and vitamin A intake. All surviving animals after the last smoke exposure were killed for analysis of plasma and liver vitamin A contents and histopathology of the lung. Plasma and liver vitamin A levels were apparently lower in hamsters fed vitamin A-free diet than those maintained on normal stock diet. Liver vitamin A content was significantly higher in vitamin A-supplemented hamsters than those on stock diet alone, although there was no significant difference in plasma vitamin A level. Histopathologically, the number of free macrophages was counted in lung sections stained with hematoxylin and eosin and the count was used as the index to evaluate smoke-related insult at different levels of vitamin A. The number of macrophages was significantly greater in the smoke-exposed hamsters on vitamin A-free diet than those on normal stock diet. However, there was no significant difference in the macrophage count between vitamin A-supplemented and unsupplemented hamsters on stock diet. These results indicate that vitamin A deficiency and smoke exposure appear to enhance pulmonary macrophage mobilization. It is possible that the respiratory epithelium of vitamin A-deficient hamsters loses its integrity and becomes susceptible to injury by irritants such as those present in cigarette smoke. The elevated pulmonary free macrophage count may be a response to the damage caused by vitamin A deficiency and smoke exposure.

Effect of vasectomy on humoral and cell‐mediated immunity in monkeys with experimentally induced atherosclerosis

The development of humoral and cell-mediated immune responses and circulating immune complexes following vasectomy were studied in rhesus monkeys fed a high cholesterol (atherogenic) diet. Four groups of monkeys were studied: (i) sham-vasectomized males fed a normal stock diet, (ii) sham-vasectomized males fed an atherogenic diet, (iii) vasectomized males fed a normal stock diet, and (iv) vasectomized males fed an atherogenic diet. Monkeys were observed for a period of 1.5 years. Sperm agglutinins and immobilizins in serum were detected in 100 and 60%, respectively, of vasectomized monkeys fed stock diet. In contrast, 60% of vasectomized monkeys fed an atherogenic diet showed agglutinins in their sera and only 20% exhibited immobilizins. The sensitization of lymphocytes by seminal plasma antigens was of a lower order in vasectomized monkeys fed an atherogenic diet as compared to those maintained on a stock diet. Circulating immune complexes (CIC) were present in both the groups of vasectomized monkeys but the level was higher in animals fed an atherogenic diet. The aortic atherosclerosis score was increased significantly in vasectomized monkeys fed an atherogenic diet, whereas the coronary atherosclerosis score was increased both in vasectomized males and in animals fed an atherogenic diet.

Reduced lipogenesis in cafeteria-fed rats exhibiting diet-induced thermogenesis.

Fatty-acid synthesis has been measured in vivo with 3H2O in cafeteria-fed rats exhibiting diet-induced thermogenesis. Synthesis was decreased in brown adipose tissue, the liver, white adipose tissue, and the carcass of the cafeteria-fed animals compared to rats fed the normal stock diet. Whole-body synthesis was also decreased in the cafeteria-fed group. Diet-induced thermogenesis, in contrast to cold-induced non-shivering thermogenesis, does not lead to increased fatty-acid synthesis and this is presumably due to the inhibitory effects on lipogenesis of the high dietary fat intake characteristic of cafeteria diets. The results also indicate that the energy cost of body fat deposition in cafeteria-fed rats is lower than in animals fed a low-fat/high-carbohydrate stock diet.

家兎の実験的動脈硬化症に及ぼすクロレラの効果

The effects of dried Chlorella powder on lipid metabolism and pathological changes of aortae were investigated in cholesterol-fed rabbits, using clofibrate for comparison. Japanese white male rabbits were fed on a high cholesterol diet for 20 weeks in the following manner: 1) High cholesterol diet (0.5% cholesterol in normal stock diet), 2) High cholesterol diet plus 1% Chlorella, 3) High cholesterol diet plus 5% Chlorella, 4) High cholesterol diet plus 0.5% clofibrate.Administration of Chlorella inhibited the increase of serum total cholesterol and phospholipid levels caused by cholesterol feeding. The percentage of atherosclerotic intimal involvement was significantly lower in Chlorella-fed groups than cholesterol-fed group. Clofibrate did not affect the levels of serum lipids, but it reduced the aortic intimal involvement.

Degradation of cytochrome P-450 heme in ascorbic acid-deficient guinea pigs

Degradation of hepatic cytochromc P-450 heme in ascorbic acid-deficient and ascorbic acid-dosed (p.o., 25 mg/100 g/body wt/day) guinea pigs was investigated by determining the turnover of radioactive cytochrome P-450 and the formation of in vivo expired carbon monoxide ( 14CO). 14CO is a specific degradation product of the labeled heme. Hepatic levels of cytochrome P-450 and cytochrome b 5 were decreased significantly (61 per cent, P < 0.001. and 29 per cent. P < 0.01, respectively) in scorbutic animals compared to ascorbic acid-adequate animals. After the administration of δ-amino-levulinic acid [3, 5- 3H], the disappearance of radioactivity from the fast-phase and slow-phase components of cytochrome P-450 heme (CO-binding pigments) exhibited half-lives of 4.2 and 30.8 hr, respectively, in the ascorbic acid-depleted guinea pigs. The turnover of cytochrome P-450 heme was similar for both phases in animals fed the ascorbic acid-deficient diet and dosed with ascorbic acid or animals fed a normal stock diet. In guinea pigs deficient in ascorbic acid and injected with [5- 14C]δ-aminolevulinic acid, the cumulative expired 14CO was similar to guinea pigs adequate in ascorbic acid. These studies demonstrate that the decrease in hepatic cytochrome P-450 content in ascorbic acid deficiency is not due to a defect in cytochrome heme catabolism. The role of ascorbic acid in stabilizing cytochrome P-450 remains to be determined.

Onion, Garlic, and Experimental Atherosclerosis

Forty-two healthy male albino rabbits weighing around 1 Kg were divided into 4 groups. Group I (8)- fed on normal stock diet, Group II (8)- fed on stock diet plus cholesterol (0.5 gm in 5 ml of olive oil). Group III (15)- received stock diet plus cholesterol plus garlic (0.25 gm) juice. Group IV (11)- received stock diet plus cholesterol plus onion (2.5 gm) juice. The animals were closely observed and followed for 16 weeks. Approximately every 4 weeks, blood samples were collected for estimation of various parameters (S. cholesterol, S. triglycerides, S. lipoproteins, S. phospolipids, and fibrinolytic activity). At the end of experiment, animals were sacrificed and degree of aortic atherosclerosis was graded (grade 0 to 4) in different groups and compared. Experimental study revealed that both garlic and onion (garlic more than onion) had significant effect in inhibiting the rise in S. cholesterol, S. triglycerides, S. beta lipoproteins, and S. phospolipids and significant effect in enhancing the fibrinolytic activity. The beta: alpha ratio was altered favourably and the ratio was kept close to normal. As regards the degree of aortic atherosclerosis as seen on post mortem, it was significantly less in garlic and onion group when compared with pure cholesterol group.

Influence of linseed oil on cholesterol-induced atherosclerosis in rabbits

Four groups of rabbits were studied to determine the effect of linseed oil on cholesterol-induced atherosclerosis. Group C received cholesterol alone; group CL received cholesterol and linseed oil, group L were given linseed oil alone, while group N were fed the normal stock diet for 18 weeks. Cholesterolemia was marked in groups C and CL but not in groups L or N. Cholesterolemia was significantly greater ( P < 0.001) in group CL (462 mg/dl) than in group C (318.6 mg/dl). Thus, the addition of linseed oil to cholesterol led to greater hypercholesterolemia than with the cholesterol diet alone. There was no significant change in the serum triglyceride level in either group. Atherosclerotic lesions (mostly fatty streaks but some fibrous plaques) were present only in groups C and CL and were absent in groups L and N. The percentage of atherosclerosic intimal involvement was significantly greater in group CL than group C ( P < 0.001). The severity of atherosclerosis correlated with serum cholesterol levels ( r = 0.79; P < 0.001), but not with serum triglyceride levels.

Regulation of energy balance in two models of reversible obesity in the rat.

Adult male rats were made obese either by tube feeding varying fractions (34%, 47%, 68% or 75%) of their normal food intake or by offering them a varied and palatable diet (cafeteria diet). After 17--30 days of these regimens, the treatments were withdrawn, and the animals were allowed free access to the normal stock diet. Tube-fed animals precisely adjusted voluntary food intake to compensate for the energy delivered by tube but nevertheless became obese as a result of an increased metabolic efficiency. Cafeteria-fed rats were hyperphagic and became obese without any apparent change in metabolic efficiency. Recovery from obesity was more rapid in the cafeteria animals and was due to a pronounced increase in heat production as well as concomitant hypophagia. Animals previously made obese by tube feeding exhibited hypophagia and returned to normal weight without any change in heat production. The relevance of these results to the concept of lipostasis and the relative roles of energy intake and expenditure in the regulation of energy balance are discussed.

Distortion of endothelial repair The effect of hypercholesterolaemia on regeneration of aortic endothelium following injury by endotoxin A scanning electron microscope study

Five young male New Zealand White rabbits were fed a semi-synthetic diet containing 0.2% cholesterol for 2 weeks and a control group of 5 animals was fed a normal stock diet. All animals were then injected intravenously with a single dose of endotoxin from Serratia marcescens (200 μg/kg body weight) and continued on their respective diets for a further 4 weeks. The aortas were then stained with silver nitrate and fixed under pressure for Scanning Electron Microscopy (SEM). Argyrophilic endothelial cells were present in both groups of animals 4 weeks after endotoxin injections. In the cholesterol-fed animals, however, these cells were often covered with pits and craters. These findings suggest that the hypercholesterolaemia may affect the regeneration of arterial endothelial cells.

Experimental atherosclerosis in swine: Effect of dietary protein and high fat

Two groups of pigs each consisting of 6 animals were fed for 18 months on isocaloric amounts of an experimental diet with a high fat content and cholesterol but with widely different levels of protein (5% vs. 25% by weight of the diet). In addition, a third group consisting of 4 animals was maintained on normal stock diet to serve as control. Animals of the low protein group showed the maximal intimal surface area involvement with atherosclerotic lesions in the aorta and coronary arteries, and also the most severe among the three groups. No significant differences were noted in the extent and severity of lesions between the high protein-high fat fed animals as compared with the high protein-low fat fed controls. Lesions of the low protein group had a higher cholesterol content and a raised cholesterol:phospholipid ratio than those in the other two groups. Extremely low levels of dietary proteins seem to have had a promotive effect on the induction of atherosclerotic lesions by an atherogenic diet, whereas adequate levels of dietary proteins have had a protective influence. The precise mechanism by which varying levels of dietary proteins have such effects is not understood. It may possibly be related to the aberrations of lipid metabolism induced by extremely low levels of dietary proteins.

Studies on progressive metabolic alterations in thioacetamide induced hepatocarcinogenesis.

Sequential studies on levels of glycogen and lactic acid as well as activities of glucose-6-phosphatase, fructose-1, 6-diphosphatase aldolase, aspartic and ornithine transcarbamylase, arginase and xanthine oxidase were carried out in liver and tumour tissue of mice fed with 0.03% thioacetamide in normal stock diet. It was observed that significant decrease in glycogen content and activities of gluconeogenic enzymes was apparent at the age of 4 months, i.e. 2 months after thioacetamide treatment. Alterations in the other parameters studied were observed later, i.e. at the age of 9 months. Maximum changes were observed in the hepatomas, i.e. at the age of 17 months.

Effects of maternal essential fatty‐acid deficiency on neonatal rat brain

AbstractFemale weanling rats were raised to sexual maturity on either a normal stock diet or an essential fatty‐acid (EFA) deficient diet, and then bred. Brain weight and lipid composition of the offspring from these animals were measured as part of an investigation into factors contributing to the early death of EFA‐deficient progeny. Lactation failure does not seem to be an adequate explanation of the early deaths since the dead EFA‐deficient offspring frequently have milk in their stomachs. Maternal behavior including nesting was lacking, however, in EFA‐deficient dams. The EFA‐deficient brains weighed less than normal neonatal brains, and frequently had subdural hemorrhaging. Relative to body weight, however, some “sparing” of the brain was apparent. Total brain sterol concentration was not measurably different, but fatty‐acid composition of total brain lipid and phospholipid was. The EFA‐deficient offspring had relatively less arachidonate and other EFA‐related fatty acids, while the proportion of trienoic acids, principally 20:3 and 22:3 was increased considerably. In phosphatidyl ethanolamine, the proportion of 16:0 was particularly elevated in the EFA‐deficient brains. The results are discussed in relation to the integrity of myelin and the synthesis of prostaglandins, as possible factors in the premature death of EFA‐deficient progeny.

Influence of diets containing different natural oils on the incorporation of [1-14C] acetate in the various lipid fractions of rat liver.

1. A comparative study was undertaken with rats on the effect of various diets (normal stock, fat-free, palm oil and olive oil) on the in vitro incorporation of [14C]acetate by the liver into cholesterol and into the fatty acids of phospholipids and neutral fats. 2. The total lipids extracted from the incubation mixtures were fractionated into acetone-precipitable and digi- tonin-precipitable portions and also into the fatty acids of neutral lipids. 3. The incorporation of [14C]acetate into the acetone-precipitable fraction and into fatty acids of neutral fats was greatest in livers of rats given the fat-free diet, followed by those of the groups given olive oil, the normal stock diet, and palm oil. Livers from the group given the fat-free diet also exhibited the highest percentage of14C activity in the digitonin-precipitable fraction and were closely followed by the group on the normal stock diet. Compared with those of the other two groups, the livers of the groups given olive oil and palm oil showed much less activity in the digitonin- precipitable fraction. 4. The greater the amount of a specific type of fatty acid in the diet, the less was the14C activity incorporated into that type of fattyacid in the ncutral fats of liver slices, hut this was not so with the fatty acids obtained froin the acetone-precipitahlc fraction of the lipids.

Dynamic Aspects of Cholesterol Ester Metabolism in Rabbits with Atherosclerosis

Rabbits were fed a normal stock diet supplemented with 1 g of cholesterol/day; at 58 days the animals received a meal labeled with cholesterol-4-C14 and were then killed at 1, 3 and 5 days. Rabbits with atherosclerosis showed a high percentage of oleic acid and a low percentage of linoleic acid in their aorta, liver and serum cholesterol esters. The specific activity data of the individual aorta and liver cholesterol esters indicate that the 3 major classes of cholesterol esters (saturated, monounsaturated and linoleate) may have different turnover rates. At 1 day, the aorta C14-cholesterol esters had a composition similar to the C14-cholesterol esters present in the serum. After 1 day the composition of the C14-cholesterol esters in the aorta showed a general shift toward the total cholesterol ester fatty acid pattern. The observations of this study support the view that there is an indiscriminate deposition of cholesterol esters into the aorta from the plasma and that the aorta determines the final composition of its cholesterol esters by a selective retention of saturated and monounsaturated esters.

Suppression of tuberculin reaction in the scorbutic guinea pig.

IN a recent publication from this laboratory it was noted that vitamin C deficiency in guinea pigs prevented induction of experimental allergic encephalomyelitis as well as development of the tuberculin reaction1. Replacement of the scorbutic diet with a normal stock diet four weeks after deprivation began and three weeks after inoculation of the challenge vaccine containing brain and killed Mycobacterium butyricum in water-in-oil emulsion permitted subsequent development of tuberculin sensitivity although the guinea pigs failed to develop clinical or histological signs of experimental allergic encephalomyelitis. It was important to determine the exact basis for the animals' failure to respond to tuberculin by development of a skin reaction because of the bearing this information might have on the induction of experimental allergic encephalomyelitis. Did absence of vitamin C prevent the end organ response (development of a positive skin reaction to tuberculin or, in the case of experimental allergic encephalomyelitis, the inflammatory lesions in the brain), or was the vitamin essential to the primary immunological response to the injected antigen(s)?

QUANTITATIVE INTERFERENCE WITH ESTROGENINDUCED TISSUE GROWTH BY FOLIC ACID ANTAGONISTS1

We have previously reported that the folic-acid deficient chick exhibits only a very limited response to even excessively high doses of administered estrogen (Hertz, 1945). A similar impairment in estrogen response has been observed in the folic-acid-deficient monkey (Hertz, 1948). Moreover, the degree of response to injected estrogen as evidenced by increase in weight of the genital tract in the chick was shown to be quantitatively related to the amount of folic acid ingested. These observations have been confirmed by Kline and Dorfman (1948). Preliminary data have been previously presented indicating that the ingestion of a chemically unidentified, crude folic acid antagonist incorporated into a normal stock diet leads to a marked reduction in genital tract response to diethylstilbestrol in chicks (Hertz, 1948). Franklin et al. (1948) have reported similar observations. The present report is concerned with further quantitative studies on the inhibition of estrogen-induced tissue growth in the genital tr...

Nicotinic acid deficiency in the pig and guinea-pig: I.—The effects of a “pellagra-producing” diet upon these species

The literature of nicotinic acid deficiency in the pig and guineapig has been reviewed. It has been confirmed that a necrotic enteritis may occur in the young pig which is provided with a “pellagra-producing” diet, and which is not infected with Salmonella suipestifer. A “pellagra-producing” diet failed to support life or health in the young guinea-pig, and proved less suitable than a normal stock diet even when supplemented by 15 per cent. of brewer's yeast.

Production of Experimental Polycythemia with Cobalt

During a continuation of our studies on nutritional anemia, a polycythemia was observed in rats receiving a certain mixture of metals with Cu as a supplement to a milk-Fe diet, whereas the same mixture of metals without Cu failed to produce this condition. The data are reported together with those from a study of the metals or combination of metals responsible for the polycythemia. Male albino rats, 26 days old, were placed in glass cages and fed whole milk for 4 days. A mixture of Mn, Co, Ni, Zn, Cu, and Fe salts was then added as a supplement to the milk diet 6 days a week. All metals were fed as the same preparations, and at the lower levels, used in our previous work. Weekly hemoglobin determinations showed normal values until the animals were 7 to 9 weeks of age, when a definite increase in hemoglobin occurred. The rats presented an extremely ruddy appearance, and their eyes, ears, and paws became deep red. When it was evident that this was not a transitory condition, hematological studies were made on the animals of this group, as well as on 2 control groups—one receiving the milk diet supplemented by Cu and Fe only, and the other, a normal stock diet. The group averages, based upon 3 determinations at weekly intervals on each rat, may be summarized as follows: The table shows that the animals on the entire mixture of metals exhibited a marked polycythemia, whereas the rats of either control group showed none. The animals showing polycythemia are now 275 days old and the condition has persisted for 30 to 32 weeks. Another group of rats, not reported here, received the mixture of metals without Cu and developed a progressive anemia rather than a polycythemia.