Effect of pure and oxidized cholesterol-rich diets on some biochemical parameters in rats.

The present study was undertaken to evaluate the peroxidative damage and hypercholesterolemia induced in male Wistar albino rats by diets enriched either with 1% oxidized cholesterol (OC) (containing 49.8% of cholesterol oxidation products) or pure cholesterol (PC). The damage caused by the OC diet was revealed by a significant rise in red blood cell hemolysis, increased tissue lipid peroxidation and elevated aspartate amino transferase activity as compared with control and PC diets. Liver glutathione-S-transferase activity was decreased by both OC (P < 0.01) and PC (P < 0.05) diets, but glutathione was observed to be decreased only by the OC diet. Plasma triacylglycerol and cholesterol were increased significantly with both the OC and PC diets. Liver cholesterol and triacylglycerol were increased significantly with the OC diet only. These results indicate that the oxidative damage caused by the OC diet is much more pronounced than that caused by the PC diet.

Changes in protein nutritional quality in fresh and recombined ultra high temperature treated milk during storage.

The objective of this study was to determine the changes in nutritional quality of protein in stored UHT milk. Commercial fresh and recombined ultra high temperature (FUHT and RUHT respectively) treated milk samples were used. Pasteurized milk (P-milk) samples were used for comparison. Milk samples were freeze-dried for the use in diet formulation. Pasteurized milk samples were freeze-dried within 24 h of production. FUHT and RUHT milk samples were freeze-dried after production (zero time), 3 and 6 months of storage at 37 degrees C. Three nitrogen balance experiments were done at zero time, after 3 and 6 months of storage. The diet used in all experiments were similar in composition except for protein source. In each experiment egg white (low protein), casein (control), P-milk, and either 0, 3 or 6 months old FUHT and RUHT milk samples were used as the source of protein in the diets. In each experiment 30 (six for each diet) male Sprague-Dawley rats were used. Apparent digestibility (AD), true digestibility (TD), biological value (BV), and net protein utilization (NPU) were calculated for protein in casein and all milk samples. The nutritional quality of protein in FUHT milk before storage was similar to that of protein in pasteurized milk, but it decreased during storage for 3 months and then remained at the same quality up to 6 months of storage. BV and NPU of protein in FUHT milk after storage for 3 and 6 months were lower than that of protein in pasteurized milk by 4% (not significant) and 5% respectively. On the other hand, the nutritional quality of protein in RUHT milk before storage was lower than that of protein in pasteurized milk and remained at the same level after storage for 3 months: however, it decreased significantly after storage for 6 months. AD and TD of protein in RUHT milk stored for 6 months were lower than that of protein in pasteurized milk by 5% and BV and NPU were lower than that of protein in pasteurized milk by 9 and 12% respectively. The above reduction in nutritional quality of protein in UHT milk may be of significant value in feeding young children who might be dependent on this type of milk in their diet.

Growth and lipid metabolism responses in rats fed different dietary fat sources.

An experiment with male albino rats was conducted to examine the effect of dietary fat sources on growth performance and apparent digestibility of total fat and fatty acids. The effect on plasma and organ cholesterol concentrations as well as lipoproteins cholesterol and fatty acid profile of hepatic phospholipids was also examined. Forty 3 week old rats were fed purified diets containing 0.041% cholesterol and 7% fat (wt/wt) from soy oil (SO), or cow ghee (GH), or 25% fish oil (FO) plus soy oil (SF) or 25% fish oil plus 75% ghee (GF), or 50% soy oil plus 50% ghee (SG) for a period of 35 days. Final body weight, weight gain, organ weights and feed efficiency ratio showed no significant differences (P < 0.05) among the dietary treatments. The apparent digestibility of total dietary fat and saturated fatty acids in the animals fed diet containing cow ghee only or in combination with fish oil or soy oil was significantly lower than the other dietary groups. Consumption of ghee with combination of fish oil or soy oil lead to significant improvement in the fat apparent digestibility of dietary fat. Total cholesterol and triglyceride concentrations of plasma and organs as well as lipoprotein cholesterol levels were higher in animals fed diets containing ghee. For rats fed diet containing cow ghee in combination with fish oil or soy oil, the cholesterol content of total plasma, lipoprotein fractions (VLDL, LDL and HDL) and organs was decreased significantly. Furthermore, dietary fats altered the fatty acids composition of hepatic phospholipid fatty acids composition. Feeding dietary fish oil reduced arachidonic acid (20:4) and increased linoleic acid (18:2) and eicosapentaenoic acid (20:5) contents. The reduction in the arachidonic acid was being more pronounced in animals fed dietary ghee with combination of fish oil.

Fatty acid composition and arachidonic acid intake of selected Saudi foods.

Twenty-eight Saudi Arabian common foods were analyzed for their fatty acid contents by gas-liquid chromatography using capillary column. The predominant fatty acids were oleic, palmitic, linoleic and stearic acids. The polyunsaturated to saturated fats ratio (P:S) as well as the n-3:n-6 ratio were generally not compatible with recommended values. Assessment of C20:4 (n-6) content in those foods showed a noticeable variation ranging from 9 mg/100 gm in beef sirloin to 256 mg/100 g in kannad fish. Eicosapentaenoic acid (C20:5) n-3 content was highest in kannad (925 mg/100 g). Applying C20:4 (n-6) values determined in this work to Saudi Balanced Sheet, the mean C20:4 (n-6) intake for a Saudian was estimated as approximately 115 mg/day.

Injuries due to motorcycle accidents amongst Saudi women. Are we waiting for a new epidemic?

Full text is available as a scanned copy of the original print version.

Neonates' vitamin A status in relation to birth weight, gestational age, and sex.

Vitamin A status was assessed in a randomly selected group of neonates at delivery. A total of 105 neonates were included in the study. Cord vitamin A concentration was determined by high performance liquid chromatography (HPLC). Of 105 neonates, 53 (50.5 per cent) were males and 49 49.5 per cent) were females. The mean body weight of male neonates was slightly greater that that of female neonates (3271 +/- 575 vs. 3139 +/- 552 g). Mean cord plasma vitamin A level of the males was significantly lower (p < 0.05) than that of the female neonates (12.2 +/- 4.6 and 14.7 +/- 5.2 micrograms/100 ml respectively). The mean body weight of premature neonates (2186 +/- 530 g) was significantly lower (p < 0.05) compared with the mean body weight of full term neonates (3279 +/- 495 g). Cord plasma of preterm neonates had mean value of vitamin A significantly lower (p < 0.05) than full term neonates (8.3 +/- 3.2 vs 13.8 +/- 4.5 micrograms/100 ml). A trend of increasing birth weight with increasing cord plasma vitamin A level was evident.

Dietary assessment of male students: a study of what they wasted while in residence.

The present study was conducted to provide the anthropometric measurements and energy intake of male university students. Edible plate waste was assessed. A total of 90 male students participated in the anthropometric study. Meal and edible plate waste were analyzed for their contents of moisture, crude protein, crude lipid, ash and fiber. Total carbohydrates were calculated by difference. Total served meals and edible plate waste were assessed quantitatively using a weight technique. Total energy intake was 85% of the RDA. The students had higher intakes of protein and fat and lower intakes of carbohydrate than the recommended levels. The collected data showed that plate waste was influenced by the timing of the meal. Plate waste was higher for dinner (39.74%) and lower for lunch (22.67%).

Pool size and concentration of plasma cholesterol are increased and tissue copper levels are reduced during early stages of copper deficiency in rats.

The progressive development of hypercholesterolemia, enlargement of plasma cholesterol pool size, and alteration in tissue mineral concentrations were determined during the early stages of copper deficiency. Fifty-four weanling male Sprague-Dawley rats were assigned to three dietary Cu treatments: deficient (0.6 micrograms Cu/g diet), marginal (1.6 micrograms Cu/g diet) and adequate (6.6 micrograms Cu/g diet). Six rats from each treatment were killed after 3, 5 and 7 wk of dietary treatment. After only 3 wk of treatment, significantly lower hematocrits and liver Cu concentrations, as well as enlargements of plasma volume, plasma pool size of cholesterol and triacylglycerols and relative heart weight, were evident in rats fed the Cu-deficient and Cu-marginal diets relative to those fed the Cu-adequate diet. In general, these alterations were more pronounced in rats fed the Cu-deficient diet than in rats fed the Cu-marginal diet. Thereafter, the hematocrits and plasma volumes remained relatively constant, but the liver Cu concentration progressively decreased in rats in all treatments throughout the study. In contrast, the enlargements in plasma pool size of cholesterol and triacylglycerols relative to Cu-adequate rats were greater at the end of the study for the Cu-marginal and Cu-deficient rats. Most importantly, in the Cu-marginal rats, significantly greater plasma cholesterol and triacylglycerol pool sizes were detected earlier than were differences in concentrations. Thus, the present study established plasma cholesterol and triacylglycerol pool sizes as superior indices for the early detection of alterations in lipid metabolism in Cu deficiency.

Copper deficiency increases in vivo hepatic synthesis of fatty acids, triacylglycerols, and phospholipids in rats.

This study examined the influence of dietary copper status on the in vivo hepatic fatty acid synthesis and the incorporation of nascent fatty acids into various hepatic lipid classes. Fifty weanling male Sprague-Dawley rats were assigned to two dietary treatments, copper deficient (5.4 nmol/g of diet) and copper adequate (102 nmol/g of diet). After 7 weeks of treatment, rats were injected with 0.111 MBq of [1-14C] acetate (1.85 GBq/mM)/100 g body wt through the femoral vein. Five rats from each treatment were sacrificed at 3, 6, 9, 12, and 24 min after injection. Radioactivities of nascent fatty acid samples were used to determine relative rates of fatty acid synthesis and their assembly into triacylglycerols and phospholipids. Linear increases were observed up to 12 min after injection for total hepatic fatty acid synthesis and their assembly into triacylglycerols and phospholipids for both treatments. In addition, 46% and 30% of total fatty acid synthesized were assembled into triacylglycerols and phospholipids, respectively, for both groups. Furthermore, hepatic fatty acid synthesis and assembly into triacylglycerols and phospholipids were enhanced more than 2-fold by copper deficiency when the data were expressed as per liver per 100 g body weight.

Lipid composition and fluidity of the erythrocyte membrane in copper-deficient rats.

The influence of dietary copper on lipid composition, phospholipid fatty acid and protein profiles and fluidity of the erythrocyte membranes of rats is reported. In general Cu deficiency in rats induced some changes in the phospholipid-fatty acid profile of erythrocyte membranes when compared with Cu-adequate animals. Stearic (18:0) and docosadienoic (22:2n-3) acids contents, for example, were significantly increased (P < 0.001) while oleic (18:1n-9) and linolenic (18:3n-3) acid contents were significantly depressed (P < 0.001) as a result of Cu deficiency. Moreover the cholesterol:phospholipids molar ratio and the cholesterol (mol):membrane proteins (mg) ratio in Cu-deficient rats were, to different degrees, significantly lower than in animals fed on Cu-adequate diets. In addition, diets deficient in Cu led to a reduction in erythrocyte membrane fluidity (P < 0.001) as assessed by the intramolecular excimer fluorescence of 1,3-di(1-pyrenyl) propane. However, no significant alteration in the phospholipid:protein ratio was observed as a result of differences in dietary treatment. The pattern of erythrocyte membrane proteins obtained with sodium dodecyl sulphate-polyacrylamide gel electrophoresis did not seem to be influenced by Cu-deficient diets.

Copper deficiency alters plasma pool size, percent composition and concentration of lipoprotein components in rats.

Forty weanling male Sprague rats were randomly assigned to two dietary treatments, copper-deficient (9.0 mumol/kg diet) and copper-adequate (102.2 mumol/kg diet). After 7 wk of treatment, reductions in body weight and hematocrit, and an increase in relative heart weight, were observed in the copper-deficient rats. Plasma VLDL, LDL and HDL were isolated by ultracentrifugation and Sepharose column chromatography. In copper-deficient rats, the percent composition of protein was reduced by one-half, and triglyceride was increased by 1.6- and 2.7-fold in LDL and VLDL fractions, respectively. In VLDL, the marked increase in triglyceride was compensated by at least a 75% decrease in percent composition of cholesterol and phospholipids as a result of copper deficiency. No treatment difference in percent composition of HDL components was detected. When the data were expressed as the amount present in the vascular pool corrected for body weight, the plasma pool size of protein, triglyceride, phospholipid and cholesterol of LDL and HDL were increased twofold or more by copper deficiency. In VLDL, a sixfold increase in triglyceride, a 36% reduction in cholesterol, and no change in phospholipid and protein pool size were observed in copper-deficient rats. These data suggest that copper deficiency may enlarge the particle size but not particle number of VLDL, increase both particle size and number of LDL, and elevate particle number but not size of HDL.

The effect of copper deficiency on rat hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase activity.

The effect of copper deficiency on hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase, the key enzyme regulating cholesterol biosynthesis, was investigated in the rat. Male weanling rats were fed semipurified diets containing adequate, marginal, or deficient levels of copper for 6 weeks. Two separate studies were conducted; in the first study, animals were fasted 12 hours prior to analysis and in the second study, animals were fed diets ad libitum. Plasma lipid levels, hepatic cholesterol concentrations, and 3-hydroxy-3-methylglutaryl coenzyme A reductase specific activity, total and active, were determined. Consistent with previous findings, plasma total cholesterol and triglyceride levels were significantly elevated in copper-deficient rats. Copper deficiency resulted in a significant decrease in hepatic total cholesterol levels. Total and active levels of 3-hydroxy-3-methylglutaryl coenzyme A reductase in fed animals were elevated twofold with copper deficiency, with the active form of the enzyme constituting approximately 30% of total activity. 3-Hydroxy-3-methylglutaryl coenzyme A reductase activity in copper-deficient fasted rats was twofold higher than for the fasted adequate animal; however, fasting did result in a 10-fold reduction in hepatic reductase specific activity. These data support the hypothesis that copper deficiency results in a hypercholesterolemic state in the rat associated with increased hepatic cholesterol synthesis.