Muscle Cholesterol Research Articles

Nutritive Value of Full-Fat Sunflower Seeds in Broiler Diets

A study was conducted to evaluate the nutritive value and inclusion level of sunflower seed (SFS) in broiler diets. SFS contained 38.7% ether extract (EE), 16.9% CP, 14.9% crude fiber (CF), 3.5% ash, 0.57% lysine, and 0.46% methionine (89.2% DM basis). The AME (kcal/ kg) content of SFS in roosters was 5,225 and in broilers at 4, 18, and 35 d of age was 3,493, 5,132, and 5,162, respectively. The CP, EE, and CF digestibilities were 80.4, 71.2, and 11.4%, respectively. In an isocaloric and isonitrogenous diet containing SFS at 0, 5, 10, 15, and 20%, SFS up to 20% did not affect weight gain and feed consumption, but the feed conversion ratio was improved (P < 0.05) when broilers were fed 15 or 20% SFS in the starter and finisher diets. CF digestibility of starter diet was significantly lower when 15 or 20% SFS was included. CF digestibility of the finisher diet and digestibility of other nutrients in starter and finisher diets were comparable in all treatment groups. Liver and muscle lipid content, plasma total and high-density lipoprotein cholesterol content, muscle cholesterol content, dressing percentage, liver weight, and giblet weight (as % live weight) were comparable among all treatment groups. Abdominal fat was increased in birds fed 20% SFS. Percentage skin was decreased in broilers fed ≥10% SFS.

Comparative nutritional evaluation of raw, methanol extracted residues and methanol extracts of moringa (Moringa oleiferaLam.) leaves on growth performance and feed utilization in Nile tilapia (Oreochromis niloticusL.)

The suitability of raw and methanol-extracted moringa (Moringa oleifera Lam.) leaf meal to replace 10%, 20% and 30% of the total fishmeal-based dietary protein in tilapia feeds was tested. Ten isonitrogenous and isocalorific feeds (35% crude protein and 20 MJ kg−1 gross energy), denoted as diets 1 (fishmeal-based control), 2, 3, 4 (containing 13%, 27% and 40% raw moringa leaf meal), 5, 6, 7 (containing 11%, 22% and 33% methanol-extracted moringa leaf meal), and 8, 9, 10 (containing methanol-soluble extracts of the raw moringa leaf meal at the same level as would have been present in diets 2, 3, 4) were prepared. Forty tilapia (16.7±2.4 g), kept individually, were fed the experimental diets (four fish per treatment) at the rate of 15 g feed per kg metabolic body weight (kg0.8) per day. A reduction in the growth performance was observed with an increasing level of raw moringa leaf meal (diets 2–4), whereas inclusion of methanol-extracted leaf meal (diets 5–7) had no significant (P<0.05) effect on the growth performance compared with the control (diet 1). The growth performance of fish fed diets 8–10 containing methanol extracts of the moringa leaf meal were also similar to the control. The chemical composition values of the gained weight showed that lipid accretion decreased with increased inclusion of moringa leaves, and ash content increased. Dietary moringa methanol extracts reduced protein accretion, but had no effects on lipid and ash contents compared with the control. The inclusion of raw, methanol-extracted residues and methanol extracts of the moringa leaf meal (diets 3 and 4, 5, 6 and 7, and 8 respectively) reduced the plasma cholesterol content significantly. Similarly, a significant reduction in muscle cholesterol was observed in fish fed the diets 4, 8, 9 and 10. It was concluded that the solvent-extracted moringa leaf meal could replace about 30% of fishmeal from Nile tilapia diets.

Comparative nutritional evaluation of differentially processed mucuna seeds [Mucuna pruriens (L.) DC. var. utilis (Wall ex Wight) Baker ex Burck] on growth performance, feed utilization and body composition in Nile tilapia (Oreochromis niloticus L.)

A fish feeding trial was conducted in a warm-water recirculating system for 8 weeks to assess the nutritive value of processed mucuna seeds as a dietary protein replacement for fish meal in practical diets of tilapia. Diets 2–6 contained mucuna seeds processed as follows: raw, soaked in water, soaked in sodium bicarbonate solution (0.07%), soaked in ascorbic acid solution (0.1%) or soaked in water containing 3% of freeze-dried moringa leaf powder, followed by autoclaving. The mucuna seed meals were then used to replace 25% of the total dietary protein in each diet. The performance of fish fed these diets was compared with fish fed a fish meal-based control diet (diet 1), which contained 35% protein. All diets were prepared to be isonitrogenous and isoenergetic. Each treatment had three replicates, using seven fish per aquarium, with a mean initial body weight of 3.9 ± 0.06 g. Fish were fed five times about their maintenance level (3.0 g feed × body weight (kg)−0.8 day−1), and no mortality was observed during the experiment. The growth rate, feed conversion ratio and protein productive value of fish fed diets 1, 3, 4, 5 and 6 were similar. However, with regard to energy retention and apparent net lipid utilization, the values observed in fish fed diet 1 were similar to those of fish fed diets 5 and 6, and diet 6, and significantly higher than other dietary groups. Fish fed diet 2 showed a significantly (P < 0.05) reduced growth performance, higher carcass moisture and ash contents, and lower levels of lipid and energy compared with all other dietary groups. Fish fed diet 2 had a significantly lower plasma cholesterol level compared with other diets. However, no significant variation of muscle cholesterol was found between the dietary groups. Even though the hepato-somatic index of the fish fed diets 3, 4, 5 and 6 was significantly lower than diet 1, these values appeared to be significantly higher compared with fish fed diet 2. The present study indicates that the inclusion of mucuna seed meal (replacement of 25% of total dietary protein of feed) after soaking in any one of the tested solutions followed by autoclaving significantly improved the growth performance and feed utilization of tilapia compared with that of the raw seeds. Moreover, these values were similar to the performance obtained with the fish meal-based control diet 1. This might be due to the relative reduction of anti-nutrients, particularly the non-protein amino acid 3, 4-dihydroxyphenylalanine, and increased palatability and nutrient availability of processed beans.

Evaluation of fat sources on cholesterol and lipoproteins using pigs selected for high or low serum cholesterol

At approximately 8 weeks of age, four-way cross (Chester White×Landrace×Large White×Yorkshire) pigs ( n=24) were selected based on genetically high (H) or low (L) serum cholesterol levels—12 from each genetic group—to determine the relationship between genetics, fat source, and sex class on plasma cholesterol, growth, carcass characteristics, and cholesterol and lipid content of muscle and adipose tissues. Boars and gilts, six each from the two genetic groups, were assigned randomly to one of three dietary treatments for 46 days. A standard grower diet was modified to include beef tallow (T), corn oil (CR) or coconut oil (CC), and the pigs were given ad libitum access to feed. Cholesterol was added to each diet to ensure the diets contained the same amount of cholesterol. Except for the plasma lipids, there were no differences between boars and gilts at the initial evaluation or at the end of the treatment; therefore, sex means were pooled for statistical analyses. Body weight was unaffected by diet on days 18, 29 or 46. Blood samples were taken on days 1, 29, and 46 via the anterior vena cava. Plasma total cholesterol (TC) and low density lipoprotein cholesterol (LDL) concentrations were greater in the H than L groups (overall TC in H and L pigs=150 and 124 mg/dl, respectively, and LDL in H and L pigs=105 and 76 mg/dl, respectively). Pigs fed diets containing saturated fats had greater TC and LDL than pigs fed unsaturated fats (TC=165, 149, and 126 mg/dl for T, CC, and CR diets, respectively, and LDL=108, 88, and 77 mg/dl for T, CC, and CR diets, respectively). There were significant time×gene×sex interactions for both TC and LDL yielding subtle differences in the response of the sexes from the two genetic groups over time. Pigs were slaughtered on day 46, and carcass data were collected. There were no differences in fat at the first rib, 10th rib, last rib, or last lumbar vertebra, but differences ( P <0.05) were found between genetic groups for M. longissimus thoracis et lumborum (LTL) muscle area (H=21.0±0.8 cm 2, L=18.1±1.0 cm 2) and USDA muscle score (H=2.1±0.1, L=1.7±0.1). There were no genetic or diet effects for cholesterol content of pre-rigor or post-rigor LTL muscle. Neither genetics nor dietary treatment affected the cholesterol content of the adipose tissue. There were no differences in fat percentage between genetic groups for muscle or adipose tissue. There were differences ( P <0.05) in total lipid content among the dietary treatments for the pre-rigor (T=6.0±0.6%, CC=4.3±0.3%, CN=3.9±0.5%) and post-rigor (T=6.4±0.9%, CC=4.1±0.3%, CN=5.0±0.4%) LTL. Cholesterol accretion in muscle and adipose tissues of growing pigs was not influenced by source of fat in the diet or by their genetic propensity for high or low plasma cholesterol.

Progressive effects of nigella sativa ogaiast the interaction of sodium nitrite and sun - set yellow in albino rats

It has been noticed that kids usually eat and drink food containing food preservator and food colorants at the same time. This behavior has been attracted the attention to study the interaction between one of food preservatives ( sodium nitrite NaNO3) and one of bood colorants (sunset -yellow S.S.Yellow). The interaction of the limited dose of these two components resulted in a lethal dose. So, 1 /10 of this dose was used for 30 days and left for another 15 days post the last dose for recovery. Other group was supplemented with Nigella sativa ( N.S) oil in addition to the same mixture. Ingestion of (NaNO3 and S.S.Yellow) mixture significantly decreased rat's body weight, RBC and WBC counts, Hb%, Hct%, serum inorganic phosphorus, serum protein and serum albumin. Significant increases were observed in serum glucose, T3, T4, calcium, -GT, LDH, CPK, Alk.ph and cholesterol. Also cholesterol of brain, liver and heart were significantly elevated. No changes were recorded for; organ/body weight, respiratory rate, heart beats, rectal temperature, acid phosphatase activity, AST and ALT activities of serum and tissues, protein of tissues, serum globulin, and total lipids of serum and tissues, cholesterol of muscle and kidney and serum triglyarides. A complete recovery of most biochemical and haematological parameters was observed days after stoppage of the mixture or after administration of Nigella sativa oil. This study ringe bells of dangerous. The study showed also that even the permitted colourants and food preservatives when taken together or if taken in excessive quantity may be harmful. Therefore, provision should be made for quantities estimation of food additives in various food stuff.

Effect of Yeast Chromium and L-carnitine on Lipid Metabolism of Broiler Chickens

A 3×4 (chromium and L-carnitine) experiment was designed to investigate the single and interactive effects of adding yeast Cr and L-carnitine to corn-soybean meal diets on lipid metabolism of broiler chickens. Four hundred and eighty one-day-old avian chickens were randomly allocated to 12 treatments of 40 each for 7 weeks. Levels of adding Cr were 0, 400, 600 µg/kg and those of L- carnitine was 0, 30, 50, 100 mg/kg, respectively. The result showed that adding 600 µg/kg Cr or 100 mg/kg L-carnitine alone had better regulative effects on fat and cholesterol metabolism than lower adding levels. Effects were more significant at the end of the experiment. There were significantly interactive effects between Cr and L-carnitine on triaclyglycerol, whole cholesterol, HDL, dissociating FFA, and blood glucose, cholesterol and triaclyglycerol of liver, and cholesterol of chest muscle at the end of experiment (p=0.0001-0.0315). But Cr or L-carnitine had no significant effect on growth performance of broiler chickens (p>0.05). (Asian-Aust. J. Anim. Sci. 2003. Vol 16, No. 12 : 1809-1815)

Ethyl icosapentate (omega-3 fatty acid) causes accumulation of lipids in skeletal muscle but suppresses insulin resistance in OLETF rats

Ethyl icosapentate (EPA) is known to improve insulin resistance in non–insulin-dependent diabetes mellitus (NIDDM); however, its mechanism is unclear. In this study, we attempted to determine the mechanism of EPA's effects on insulin resistance in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. Administration of EPA caused a reduction in plasma cholesterol and triglycerides, but increased cholesterol and triglyceride contents in skeletal muscle. EPA did not have an effect on glucose or insulin levels. EPA accelerated the glucose infusion rate (GIR) and improved the endothelium-dependent relaxation of OLETF rat the thoracic aorta caused by addition of acetylcholine. However, the improvement observed in endothelium-dependent relaxation disappeared after addition of Nw-nitro-L-arginine (L-NA). Furthermore, when L-NA and indomethacine were added to the medium, relaxation of the aorta in EPA-treated rats was weaker than that in control rats. These actions may cause NO induction in the endothelium and an increase in prostaglandin I2 (PGI2) and prostaglandin I3 (PGI3) action, which in turn may result in improvement of insulin resistance. Copyright 2003, Elsevier Science (USA). All rights reserved.

A heterozygote phenotype is present in the jvs +/− mutant mouse livers

The juvenile visceral steatosis ( jvs) mouse, having a mutation in the carnitine transporter gene Octn2, is a model of primary systemic carnitine deficiency in humans (SCD, OMIM 212140). Like humans with SCD, homozygous jvs −/− mice have hepatic and cardiac steatoses, reduced plasma and tissue carnitines, and increased urinary carnitine clearance. Because symptomatic heterozygotes have been reported for some fatty acid oxidation disorders, including SCD, we compared the jvs heterozygotes to normal control mice. We measured the free and esterified carnitine, total cholesterol, and triglycerides in adult liver samples, myocardium, and skeletal muscle. Our results indicate significant differences between the livers of nonfasting adult normal ( n=8) vs jvs heterozygotes ( n=8) ( means± SEM, p<0.01) for the following parameters: free carnitine, 2.28±0.36 nmol/ mg protein vs 0.41±0.13; total carnitine, 3.48±0.36 vs 1.27±0.25; triglycerides, 0.14±0.04 vs 0.39±0.02; and total cholesterol, 0.21±0.02 vs 0.39±0.04, but not for esterified carnitine, 1.18±0.17 vs 0.90±0.17 ( p>0.05). There is also a negative correlation between hepatic free carnitine and triglycerides from jvs heterozygotes ( p<0.05). Similar results were obtained with myocardium and skeletal muscle. We conclude that free and total carnitine levels are significantly lower in the heterozygote mouse liver and heart while triglyceride and total cholesterol levels are significantly higher. We speculate that in situations of lipolytic stress, some SCD heterozygotes might develop clinical symptoms of carnitine deficiency.

Effects of different fibre sources and fat addition on cholesterol and cholesterol‐related lipids in blood serum, bile and body tissues of growing pigs

Knowledge is limited on the efficacy of hindgut-fermentable dietary fibre to reduce blood, bile and body tissue cholesterol levels. In three experiments with growing pigs the effects of different kinds and levels of bacterially fermentable fibre (BFS) on cholesterol metabolism were examined. Various diets calculated to have similar contents of metabolizable energy were supplied for complete fattening periods. In the first experiment, a stepwise increase from 12 to 20% BFS was performed by supplementing diets with fermentable fibre from sugar beet pulp (modelling hemicelluloses and pectin). Beet pulp, rye bran (modelling cellulose) and citrus pulp (pectin) were offered either independently or in a mixture in the second experiment. These diets were opposed to rations characterized in carbohydrate type by starch either mostly non-resistant (cassava) or partly resistant (maize) to small intestinal digestion. The third experiment was planned to explore the interactions of BFS from citrus pulp with fat either through additional coconut oil/palm kernel oil blend or full-fat soybeans. In all experiments the increase of the BFS content was associated with a constant (cellulose) or decreasing (hemicelluloses, pectin) dietary proportion of non-digestible fibre. In experiment 1 an inverse dose-response relationship between BFS content and cholesterol in blood serum and adipose tissue as well as bile acid concentration in bile was noted while muscle cholesterol did not respond. In experiment 2 the ingredients characterized by cellulose and hemicelluloses/pectin reduced cholesterol-related traits relative to the low-BFS-high-starch controls whereas, except in adipose tissue cholesterol content, the pectinous ingredient had the opposite effect. However, the changes in serum cholesterol mainly affected HDL and not LDL cholesterol. Adipose tissue cholesterol also was slightly lower with partly resistant starch compared to non-resistant starch in the diet. Experiment 3 showed that the use of citrus pulp increased serum cholesterol concentrations when levels were low in the corresponding low-BFS diets (low-fat and soy bean diets), but caused no further increase in the coconut-oil/palm kernel oil blend diet. From the present results it seems that fermentable hemicelluloses have a more favourable effect of decreasing metabolic cholesterol and related traits than hardly digestible fibre, fermentable cellulose or, particularly, pectin. Furthermore, some types of fibre expressed a certain potential to reduce cholesterol content of fat pork and pork products by up to 10% (experiment 1) and 25% (experiment 2).

Three lipoprotein receptors and cholesterol in inclusion-body myositis muscle.

An important aspect of inclusion-body myositis (IBM) vacuolated muscle fibers (VMF) is abnormal accumulation of amyloid-beta precursor protein (AbetaPP) epitopes and its product, amyloid-beta (Abeta), and of phosphorylated tau (p-tau) in the form of paired helical filaments. Lipoprotein receptors and cholesterol are known to play an important role in AbetaPP processing, Abeta production, and tau phosphorylation. In 10 IBM and 22 control muscle biopsies the authors immunolocalized low-density lipoprotein receptor (LDLR), very low-density lipoprotein receptor (VLDLR), and low-density lipoprotein receptor-related protein (LRP), and colocalized them with Abeta, p-tau, APOE, and free cholesterol. In each biopsy, virtually all IBM VMF had strong LDLR-immunoreactive inclusions, which colocalized with Abeta, APOE, p-tau, and free cholesterol. VLDLR was increased mainly diffusely, but in approximately 50% of the VMF it was also accumulated in the form of inclusions colocalizing with Abeta, APOE, and free cholesterol, but not with p-tau. LRP inclusions were present in a few VMF. In all myopathies, a subset of regenerating and necrotizing muscle fibers had prominent diffuse accumulation of both LDLR and free cholesterol. At normal neuromuscular junctions (NMJ) postsynaptically, LDLR and VLDLR, but not LRP, were immunoreactive. 1) Abnormal accumulation of LDLR, VLDLR, LRP, and cholesterol within IBM vacuolated muscle fibers suggests novel roles for them in the IBM pathogenesis. 2) Expression of LDLR and VLDLR at normal NMJ suggests physiologic roles for them in transsynaptic signaling pathways, increased internalization of lipoproteins there, or both. 3) Increased LDLR and free cholesterol in some regenerating and necrotizing muscle fibers suggest a role for them in human muscle fiber growth and repair and necrotic death.

Dietary effects on muscle fatty acid composition of finished heifers

The effects of diet on Longissimus muscle fatty acid composition was determined using 24 crossbred heifers of Simmental vs. Nelore and Limousin vs. Nelore. The experimental diets were: 1) corn and yeast (CY); 2) corn, cottonseed meal + meat and bones meal (CMB); 3) cassava hull and yeast (CHY); 4) cassava hull, cottonseed meal + meat and bones meal (CHMB). Feeding CHMB diets resulted in lower lipid and higher cholesterol contents (P&lt;0.05) for both crosses. Most of the identified fatty acids were monounsaturated, and the highest percentage was found to oleic acid (C18:1w9), with values ranging from 32.54 to 46.42%. Among the saturated fatty acids the palmitic acid (C16:0) showed the highest percentage, with its contents ranging between 19.40 and 32.44%. The highest polyunsaturated/saturated fatty acid ratio was of 0.30, and the lowest was of 0.08. Feeding CY diets resulted in lower cholesterol and higher polyunsaturated fatty acid contents of the Longissimus muscle.

Characteristics of steers of six beef breeds fattened from eight months of age and slaughtered at a target level of intramuscular fat – II. Meat quality

Abstract. Meat quality of Angus (AN), Simmental (SI), Charolais (CH), Limousin (LI), Blonde d'Aquitaine (BL), and Piedmontese (PI) steers (n = 22 per breed group) was measured in the M. longissimus dorsi (M.l.d.) and the M. biceps femoris, regio glutea (M.b.f.). Animals were fattened in two subsequent series on a forage-based diet until a target level of 3.5 % intramuscular fat (IMF) was reached aecording to real-time ultrasound assessments in the live animals or until 15 months of fattening had passed. Series 1 was performed in a tie-stall barn while a loosehousing system with straw bedding was applied in series 2. The actually measured IMF contents in M.l.d. were 3.35, 3.47, 3.49, 3.48, 2.34 and 2.40 % for AN, SI, CH, LI, BL and PI, respectively. Breed group differences in IMF content were mostly accompanied by a contrary Variation either in muscle water or protein content. Muscle cholesterol levels were similar for all breeds amounting to 47 and 51 mg/100 g on average in M.l.d. and M.b.f, respectively. Early and late postmortem muscle pH was relatively similar among breeds, but water-holding capacity, measured as losses due to drip, ageing, thawing and cooking, was unfavourably high in AN (drip loss excepted) in both muscles. Cooking loss tended to be lowest in PI, drip loss in SI. The AN showed the palest meat. In line with lightness, heme iron contents were clearly lowest in both muscles in the AN steers. There was no relationship found between IMF and shear force among breed groups. No significant differences between breed groups occurred in M.l.d. collagen solubility and shear force. Apart from breed differences, there were several differences noted between fattening series, namely clearly better water-holding capacity and lower shear force of the meat from series 2 (group housing) than from series 1 (tied System). The results indicate that in steers of similar IMF content and raised under the same feeding and management conditions, differences in most M.l.d. and M.b.f. quality traits were apparent, with the exception of shear force and M.l.d. collagen solubility.

Effects of Quillaja saponins on growth, metabolism, egg production and muscle cholesterol in individually reared Nile tilapia ( Oreochromis niloticus)

The effects of supplementation of a Quillaja saponin (QS) mixture in the diets of tilapia have been studied using a respirometer system that allowed feeding and continuous measurement of oxygen consumption of individual fish. Five fish each were given control diet (C group) and control diet supplemented with 150 mg kg −1 (S150 group) or 300 mg kg −1 (S300 group) QS. At the end of 14 weeks the weight gain of the S300 group was significantly higher than control ( P<0.05) whereas that of the S150 group had an intermediate value. The S150 group had a higher growth rate ( P=0.05) after the first 3 weeks of feeding with the experimental diets, compared to the other two groups. At the end of the experiment the S300 group had significantly higher ( P<0.05) average values for energy retention, apparent lipid conversion, carcass fat, energy and significantly lower ( P<0.05) average values for apparently unutilised energy and carcass ash content compared to the C group. The corresponding values of the S150 group were intermediate between the C and S300 groups. One out of two female fish in the S150 group and both female fish in the S300 group never produced eggs during the entire 14-week experimental period. Contrarily, all three female fish in the control group and one out of the two female fish in the S150 group regularly produced eggs, at a rate of approximately once in every 14 days. The muscle cholesterol level in the S300 group was significantly higher than that of the C group. Possible mechanisms of action of the dietary saponins are discussed.

Altos níveis dietéticos de cobre no desempenho e no colesterol sérico e muscular de frangos de corte

O cobre, em níveis supranutricionais nas dietas de frangos de corte, atua como promotor do crescimento. Para avaliar as respostas no desempenho e no colesterol sérico e muscular de frangos de corte, 1200 pintos (600 machos e 600 fêmeas) receberam rações suplementadas com 50, 100 ou 150 mg kg-1 de cobre como citrato cúprico, ou 200 mg kg-1 de cobre como sulfato cúprico pentahidratado, ou uma dieta controle, não suplementada, em um experimento em blocos casualizados com três repetições e arranjo fatorial de cinco tratamentos e dois sexos. As rações, baseadas em milho e farelo de soja e adequadas em todos os nutrientes (12 mg kg-1 de cobre na dieta controle), e água foram fornecidas à vontade durante o experimento de 42 dias. Não houve efeito (P&gt;0,05) de tratamentos nas variáveis ganho de peso, consumo de ração (CR), conversão alimentar (CA) e mortalidade + refugagem (M+R) nos períodos de 1 a 21 dias e de 22 a 42 dias, com valores médios de 0,778 e 1,501 kg para GP, 1,181 e 3,087 kg para CR, 1,540 e 2,060 para CA, 1,42 e 2,08 % para M+R, respectivamente. Ao final do experimento o peso vivo (2,310 kg), o ganho de peso diário (55 g), o fator de produção (282,2), o colesterol no soro sangüíneo (129 mgdL-1) e o colesterol no músculo (55,9 mg 100 mL-1) também não foram afetados pelos tatamentos (P&gt;0,05). Os machos e as fêmeas tiveram níveis semelhantes de colesterol (P&gt;0,05) no soro e no músculo.

Progressive effects of the interaction of Sodium nitrite and sunset yellow on different physiological parameters in albino rats

It has been noticed that the Egyptian children usually eat and drink food containing both food preservative and food colourants at the same time . This has attracted the attention to study the interaction between one of food preservatives (sodium nitrite) and a food coloring agent (sunset yellow). The mixture of the two agents at the limited dose of each was found to be a lethal dose. So, 1/10th of this dose was used daily for 30 days. Animals were devided into three groups. The first group served as a control, while the second group was orally administered a mixture of 10mg sod. nitrite (NaNO3)/kg and 0.5 mg/ kg /day sun set yellow (S.S.Y)/. The third group received selenium (5 mcg/kg) in addition to the above mentioned mixture. After 30 days of treatment, half of the animals from each group were decapitated. The other half of animals was left for another 15 days without treatment for recovery. Ingestion of the mixture of (NaNO3 and S.S.Y) significantly decreased rat body weight, R B C and WBC counts, Hb %. , Hct %. Serum inorganic phosphorus, serum protein and serum albumin. Significant increases were observed in serum glucose, T3, T4, calcium, GGT, LDH, Cpk, ALK.ph and cholesterol. Also cholesterol of brain, liver and heart were significantly elevated. No changes were recorded for organ/ body weight, respiratory rate, heart beats, rectal temperature, AST and ALT activities of serum and tissues, acid phosphatase activity, total lipids of serum and tissues, cholesterol of muscle and kidney and serum triglycerides A complete recovery from the abnormalities of most biochemical and haematological parameters was observed after 15 days recovery or when selenium was administered This draws attention to the dangers of interactions of such preservatives and colorants. The present study showed that even the permitted doses of colourants and food preservatives may be harmful.

Performance, carcass characteristics, and lipid metabolism in growing and finishing Simmental steers fed varying concentrations of copper.

An experiment was conducted to determine the effects of dietary copper (Cu) on performance, carcass characteristics, and lipid metabolism in Simmental steers. Thirty-six Simmental steers (329.3 +/-11.4 kg) were stratified by weight and randomly assigned to treatments. Treatments consisted of the following: control (no supplemental Cu) and 10 or 40 mg Cu/kg DM from Cu sulfate. Each treatment consisted of six replicate pens, with each pen containing two steers. A corn silage-soybean meal-based diet was fed for 56 d. Steers were then switched to a high concentrate diet. Performance was not affected by treatment during the growing or finishing phases. Plasma Cu concentrations were higher (P < 0.05) in steers receiving supplemental Cu by d 56 of the growing phase and remained higher (P < 0.05) at all 28-d sampling periods during the finishing phase. Liver Cu concentrations were higher (P < 0.001) in steers receiving supplemental Cu at the end of the growing phase and on d 84 and at the end of the finishing phase. Steers supplemented with 40 mg Cu had higher (P < 0.001) liver Cu concentrations than those supplemented with 10 mg Cu/kg DM. Serum and longissimus muscle cholesterol concentrations were similar between treatments. Longissimus muscle and backfat fatty acid composition was similar between treatments. These results indicate that Cu supplementation given to Simmental steers increased Cu status but had no effect on performance, carcass characteristics, or lipid or cholesterol metabolism.

Primary responses of rainbow trout to dietary phosphorus concentrations

A series of experiments was conducted to research sensitive indicators for phosphorus status of fish using post-juvenile rainbow trout. Fish were fed up to 24 days with semipurified diets that varied in phosphorus content. Concentrations of glucose-6-phosphate, ATP, creatine phosphate, glucose, total lipids and total cholesterol in blood or skeletal muscle were relatively unchanged by the 24 days of dietary phosphorus restriction. Inorganic phosphorus and ATP levels in the blood, however, correlated significantly and positively. Inorganic phosphorus levels in plasma and urine were significantly lower in fish fed phosphorus-deficient diets than phosphorus-supplemented diets. Urinary phosphorus excretion peaked 6–10 h after feeding fish with diets containing potassium phosphate. Fish receiving either commercial feeds or experimental diets containing phosphorus as fish bone excreted trace amounts of phosphorus in the urine. Faecal content of phosphorus significantly increased when the diet containing potassium phosphate was supplemented with calcium carbonate. Urinary phosphorus concentration was found to be a rapid and sensitive indicator for dietary intake of phosphorus and probably phosphorus status of the fish, and had an advantage over conventional response variables in estimating dietary phosphorus requirement especially with large commercial-size fish.

Influence of dietary fat source and copper supplementation on broiler performance, fatty acid profile of meat and depot fat, and on cholesterol content in meat

1. Three hundred and twenty d-old chickens were fed on a wheat/maize‐soyabean meal diet supplemented with (i) 50 g/kg lard, (ii) 25 g/kg lard and 25 g/kg rapeseed oil, (iii) 50 g/kg rapeseed oil, and (iv) 50 g/kg rapeseed oil and 200 mg copper per kg as copper sulphate pentahydrate. 2. Final weights at 39 d of age in chickens receiving rapeseed oil were lower by 9% than in those fed on the diet containing only lard ( P <0.05). The fatty acids profiles of lipids extracted from the tissues of 10 chickens per group reflected those of the diets. 3. The polyunsaturated fatty acid (PUFA) content of breast muscles and abdominal fat (expressed as a percentage of total fatty acids) was increased and the ratio of n-6:n-3 fatty acids was decreased by the substitution of lard by rapeseed oil ( P <0.001). These changes were more pronounced for the adipose tissue than for breast muscles. 4. Copper sulphate supplementation increased the final body weight of chickens by 4.3% ( P <0.05), reduced the saturated fatty acid (SFA) proportion ( P <0.05) in abdominal fat and increased the PUFA:SFA ratio ( P <0.05). The magnitude of improvement, however, was small. 5. The substitution of rapeseed oil for lard decreased the concentration of cholesterol in breast muscles by 13%. Copper supplementation further reduced the cholesterol content by 25%. Both effects were significant ( P <0.001).

Visualizing Cholesterol

Cholesterol is an important lipid that contributes to membrane fluidity and the formation of membrane microdomains. Changes in cholesterol levels can alter signaling processes in cells. Cholesterol is commonly considered to be a constituent of the plasma membrane. Clarke et al . challenge this view with data from human and rat skeletal muscle immunostained with an antibody that recognizes cholesterol. They find that the cholesterol-specific antibody recognizes primarily a structure that morphologically resembles the sarcoplasmic reticulum. Furthermore, the cholesterol antibody colocalized with an antibody against the Ca 2+ ATPase of the sarcoplasmic reticulum and did not overlap with an antibody against the plasma membrane-localized dihydropyridine receptor. Clarke, M.S.F., Vanderburg, C.R., Bamman, M.M., Caldwell, R.W., and Feeback, D.L. (2000) In situ localization of cholesterol in skeletal muscle by use of a monoclonal antibody. J. Appl. Physiol. 89 : 731-741. [Abstract] [Full Text]

In situ localization of cholesterol in skeletal muscle by use of a monoclonal antibody.

A common perception is that cholesterol, the major structural lipid found in mammalian membranes, is localized nearly exclusively to the plasma membrane of living cells and that it is found in much smaller quantities in internal membranes. This perception is based almost exclusively on cell fractionation studies, in which density gradient centrifugation is used for purification of discrete subcellular membrane fractions. Here we describe a monoclonal antibody, MAb 2C5-6, previously reported to detect purified cholesterol in synthetic membranes (Swartz GM Jr, Gentry MK, Amende LM, Blanchette-Mackie EJ, and Alving CR. Proc Natl Acad Sci USA 85: 1902-1906, 1988), that is capable of detecting cholesterol in situ in the membranes of skeletal muscle sections. Localization of cholesterol, the dihydropyridine receptor of the T tubule, and the Ca(2+)-ATPase of the sarcoplasmic reticulum (SERCA2) by means of double and triple immunostaining protocols clearly demonstrates that cholesterol is primarily localized to the sarcoplasmic reticulum membranes of skeletal muscle rather than the sarcolemmal or T tubule membranes. The availability of this reagent and its ability to spatially localize cholesterol in situ may provide a greater understanding of the relationship between membrane cholesterol content and transmembrane signaling in skeletal muscle.