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1.
Weanling male Wistar rats were fed 20% protein diets based on casein or either of two combinations of soy protein isolate and ground raw soy providing three levels of soybean trypsin inhibitors (SBTI; 0,448 and 808 mg of trypsin inhibited per 100g of diet respectively). DL-ethionine was included at three levels (0,0.05% and 0.10%) with each level of SBTI. After 4, 8 and 12 weeks ofad libitum feeding, diets containing SBTI without DL-ethionine were associated with decreases in weight gain, feed efficiency, serum cholesterol and serum urea nitrogen. Higher levels of triglycerides, glutamate pyruvate transaminase (SGPT) and altered serum free amino acid levels were also found. Increased dietary levels of DL-ethionine also resulted in deficits in growth and feed efficiency, decreased serum cholesterol, increased SGPT and similar alterations in serum free amino acids. Combination of dietary SBTI with DL-ethionine resulted in even greater growth deficits and serum cholesterol decreases as well as increases in SGPT and serum triglycerides and changes in serum free amino acid levels. Methionine deficiency in the young rats fed SBTI and DL-ethionine was indicated by the changes in serum amino acids and growth deficits. Moderation of some effects over the 12 week test period suggested decreased methionine requirements in the older rats.  相似文献   

2.
In two year feeding trials, histologic changes in the pancreas of the Wistar rat were evaluated after chronic dietary exposure to raw and heated, dehulled, defatted soy flour and soy protein isolates which provided a range of trypsin inhibitor (TI) concentrations from 93 to 1271 mg/100 g diet. Also investigated was the nutritional interaction of level of dietary protein with the development of pancreatic pathology. Graded levels of TI were achieved from mixtures of raw and heated soy flour or protein isolate. Dietary protein levels were 10%, 20%, and 30%; the two higher levels obtained in some diets through casein supplementation. A total of 26 diets, including casein controls, were fed to groups of 40 male rats. Growth rates with these diets were commensurate with protein quality and level. Mortality rates tended to be slightly greater in the higher protein diets, and rats fed only raw soy as a source of protein survived well.Two lesions, nodular hyperplasia (NH) and acinar adenoma (AA) constituted the major pathological findings in the pancreas, and the incidence rates of both were positively associated with the concentration of dietary TI. The incidences of pancreatic NH and AA compared to those of the corresponding casein control were significantly elevated in rats fed heated soy flour supplying 10% protein and the lowest level of TI investigated (93 mg/100 g diet). At low levels of TI (215 mg/100 g diet), supplementation by casein to raise the concentration of protein from 10% to 20% and 30% reduced the frequency of NH and AA. When the dose-response data for NH and AA was linearized by plotting the probit of percent incidence against log of TI concentration per gram of dietary protein, the response to soy flour and soy protein isolate was not significantly different. Numerous lesions commonly found in the aging rat were diagnosed, and modulation of their rate of occurrence by nutritional factors associated with the diets was apparent in some instances.Reference to a company and/or product named by the Department is only for purposes of information and does not imply approval or recommendation of the product to the exclusion of others which may also be suitable.  相似文献   

3.
Numerous factors affect plasma cholesterol and, therefore, representpotential interferences with the specific effects of diet on lipid metabolism.After casein intake, serum cholesterol levels depend on many experimentalconditions in rats, such as the type of casein, the presence or absence ofcholesterol in the diet, the age and strain of rat, the diet composition, thenutritional status. The effect of fasting duration on selected parameters wasstudied in adult male Wistar rats fed a 20% casein and 1% cholesterol-based diet. No changes were observed in total serum, lipoproteins-B andHDL cholesterol and in triglyceride values after an 8 h-fast compared tonon-fasted animals. A significant decrease was induced in total andlipoproteins-B cholesterol with a 12 h-fast. A prolonged fast resulted ina significant decrease in these parameters and in triglycerides and inHDL-cholesterol levels.Fasted animals fed heated soybean meal instead of casein did not display amarked decrease in serum lipids. It appeared that the fasting effect wasmore marked in animals fed casein than in animals fed soybeans. Theseresults showed the importance of experimental conditions such as nutritional status ofanimals when blood samples are taken in studies of the hypocholesterolemiceffect of soy protein compared to casein.  相似文献   

4.
The hypocholesterolemic effect of dietary proteins could not be related to their vegetal or animal origin and seemed correlated to their different amino acids proportions. Comparing rats fed soy protein diet to those fed casein diet for 45 days, we observed a decrease of serum HDL cholesterol levels. Furthermore sequential centrifugation showed a decrease of HDL2–3 fraction and especially apolipoprotein E in the serum of soy protein fed rats. The sodium phytate, added to the diet, did not change the metabolism of sterols.  相似文献   

5.
The effect of inclusion of cashew globulin to a casein diet on lipid metabolism was studied in rats fed diets with two levels of cashew globulin meal. Inclusion of cashew globulin to a casein diet produced lower levels of total cholesterol, triacylglycerol and phospholipids in the serum and tissues and lower levels of serum lipoprotein cholesterol. There was decreased cholesterogenesis in the liver as evidenced by decreased activity of HMG CoA reductase and decreased release of lipoproteins into circulation. Rats fed cashew globulin along with casein also showed higher activity of LPL in the heart and adipose tissue and higher activity of LCAT. Increased hepatic diversion of cholesterol to bile acid synthesis and increased excretion of bile acids and sterols were also observed in these groups. Activity of glucose-6-phosphate dehydrogenase and malic enzyme was decreased in rats fed cashew globulin along with casein. This study demonstrates that cashew globulins included in the diet of rats are able to alter lipid metabolism which results in lower levels of lipid parameters in the serum and tissues.  相似文献   

6.
Previous research carried out in an animal model of retinoid-induced hypertriglyceridemia – rats fet a 13-cis retinoic acid (13cRA)-containing diet having casein as the protein source – has demonstrated that the complete replacement of dietary casein with soy protein isolate (SPI) can decrease the severity of this condition. In this study, the effect of partially replacing dietary casein with SPI was investigated. Five groups of male Fischer 344 rats were used in a 14-day study, with two groups being fed diets having casein as the protein source, without or with 13cRA (groups A and B, respectively), and three groups being fed 13cRA-containing diets in which SPI was used to bring about the isonitrogenous replacement of 25, 50, or 100% of the casein in the formula for the diet used for group B (groups C-E, respectively). Serum triglyceride concentration for group B was significantly different ( p < 0.05) from that of groups A, D, and E (5.41 vs 2.62, 4.04, and 2.66 mmol/l, respectively). Serum cholesterol concentrations for groups D and E were significantly lower ( p < 0.05) than for groups A and B (1.63 and 1.60 vs 2.00 and 2.14 mmol/l, respectively). Thus, the isonitrogenous replacement of 50% of dietary casein with SPI can reduce the severity of retinoid-induced hypertriglyceridemia while decreasing the serum concentration of cholesterol.  相似文献   

7.
A feeding trial was conducted in order to evaluate the potential effect on the lipid profile in a experimentally induced situation of hypercholesterolemia of a previously uninvestigated legume (Cicer aretinum L.) widely included in Mediterranean and Latinamerican human diets. Rats fed on a hypercholesterolemic diet containing saturated fat, cholesterol and cholic acid (H) had 123 percent higher serum cholesterol and 62 percent greater triacylglycerols levels than the animals receiving casein (C) protein. The LDL and VLDL cholesterol levels were 1330 percent and 35 percent higher, respectively, and HDL cholesterol 34 percent lower in the group of animals given the H diet as compared to controls. Further feeding of the hypercholesterolemic rats with animal protein (HC) resulted in a significant decrease of triacylglycerols (–70 percent), which reflected the decrease in the VLDL fraction. These effects on the lipid metabolism were more marked when the legumeCicer aretinum L. was present in the diet (HL). Significantly decreased concentrations of total cholesterol (–54 percent) and triacylglycerols (–70 percent) as well as the levels of LDL (–54 percent) and VLDL (–70 percent) were seen in rats fed chickpeas. In conclusion, a differential hypocholesterolemic effect between dietary casein and chickpea intake in a model of hypercholesterolemia induced by the diet was found, with beneficial effects on the lipid metabolism when legume was included in the diet as compared to casein. This suggests, for apparently the first time, that chickpea consumption may have a corrective effect in some alterations of the lipid profile.Abbreviations ANF Antinutritional factors - CD Cardiovascular disease - C Casein diet (Control diet) - H Hypercholesterolemic diet - L Legume diet - SD standard deviation  相似文献   

8.
Values (%) for true digestibility of crude protein and individual amino acids in 20 selected foods were determined by the rat balance (fecal) method. The products were fed as the sole source of protein in diets containing 8% crude protein (N × 6.25). Lowest true protein digestibility values (79–84) were obtained for pinto beans, kidney beans and lentils; intermediate values (89–92) were obtained for chick peas, beef stew, skim milk (over heated), rolled oats, whole wheat cereal, and pea protein concentrate; and highest values (94–100) were obtained for sausage, macaroni-cheese, rice-wheat gluten cereal, skim milk, tuna, soy isolate, peanut butter, chicken frankfurters, beef salami, casein and casein + methionine. In animal foods, peanut butter and soy isolate, the differences between true digestibility of crude protein and most individual amino acids were less than 5%. However, the values for true digestibility of methionine and cystine were up to 44% lower than those of crude protein in pinto beans, kidney beans, lentils, chick peas and pea concentrate. In these legumes, digestibility of crude protein was not a good predictor of digestibility of the limiting amino acids.  相似文献   

9.
This study investigated the nutritional effect of sunflower seed proteinfraction (SSPF) extracted with isopropanol on growth, plasma and tissuelipid profile, protein content and erythrocyte membrane lipid profile ofrats. Dehulled sunflower seeds were extracted with isopropanol at 50±1 °C resulting in a protein fraction (71.5%) with low residualchlorogenic acid (0.07%) and fiber (3.3%) contents. Rats fed thesunflower seed protein fraction had a similar body weight gain and foodefficiency ratios in comparison to those fed casein. Rats fed SSPF incontrast had a significantly higher growth and food efficiency ratio thanthe rats fed sunflower meal (SM), extracted with hexane. However,dietary proteins exerted a separate effect on plasma total cholesterol,low density lipoprotein (LDL)-cholesterol, low density lipoprotein to highdensity lipoprotein cholesterol (LDL-C/HDL-C) ratio and triglyceridecontent. Sunflower seed protein fraction resulted in a significantdecrease in plasma cholesterol (p < 0.05) and LDL-cholesterol (p <0.02) levels compared to the casein fed rats. Membrane phospholipidprofile also showed a marked variation with the type of dietary protein.Rats fed SSPF and SM did not show much variation in plasma lipids, plasmaproteins, liver and brain lipids and membrane phospholipid concentrations.Protein content, liver and brain lipid profile of the groups fed SSPF andcasein were comparable, suggesting that the nutritional value of SSPF isbetter than SM and equivalent to that of casein.  相似文献   

10.
The effects of cowpea and amino acid supplementation on the protein quality and chemical characteristics of a maize-based West African traditional weaning food were studied. Process optimization for improved nutritive value was also determined. Supplementation of the traditional weaning food with cowpea increased the lysine, tryptophan and threonine content while the sulphur-amino acids decreased with increasing levels of cowpea. Further supplementation of 70:30 maize/cowpea blends with lysine, threonine or methionine did not significantly improve (p>0.05) protein quality in terms of the biological value (BV) and net protein utilization (NPU), although significant increases in the protein scores were noted. However, considerable improvements in the BV and NPU were recorded in blends fortified with either tryptophan alone or a combination of lysine, tryptophan, methionine and threonine. Cooking whole cowpea seeds for 45 min before incorporating in the blend formulation also significantly improved (p<0.05) the protein quality of maize/cowpea blends. The BV and NPU of blends containing 30% pre-cooked cowpea increased from 52 to 76% and 50 to 71% respectively compared to pure maize porridge. The protein content increased from 10 to 14% and the utilizable proteins more than doubled. The weight increase of experimental rats fed with these blends was comparable to that of rats on casein diet. A 30% supplementation of the maize-based weaning food with cowpea therefore greatly enhances the nutritive value especially when the cowpea is pre-cooked for 45 min. Use of chemical scores alone for such blends cannot be a reliable index of blend quality.  相似文献   

11.
A basal diet (containing 20% soybean protein isolate) was supplemented with limiting amino acids (AA, methionine, threonine and tryptophan); wheat bran (WB, 24.3%); amylose (AM, 10%) or a combination of AA and WB or AM to investigate their effects on the levels of blood serum urea nitrogen (BUN), other blood parameters, growth and fecal characteristics in young rats. After 3 weeks feeding, supplementation of the basal diet with AA or WB resulted in improved growth (gain/food ratio) while the addition of AM had no effect on rat growth. Addition of WB to the basal diet had no effect on BUN while the addition of AA and AM caused about 20 and 12% reduction in BUN values, respectively. Rats fed the AA-AM diet had the lowest BUN values (42% lower than those fed the basal diet). Fresh volume, fresh weight, moisture and dry weight of feces in rats fed the WB diets were about four to five fold higher than in those fed the AM diets. The results suggested that BUN may not be a good predictor of growth and protein quality in diets containing AM or a source of dietary fiber (WB).  相似文献   

12.
The protein quality of algaeSpirulina platensis was evaluated biochemically in adult albino rats by serum protein regeneration studies. Rats depleted for 12 days were repleted for 15 days with diets containing 10% protein derived from algae, methionine supplemented algae, or casein. On protein depletion, the activity of the hepatic enzymes, succinic dehydrogenase and alanine aminotransferase, were lowered while the activity of alkaline phosphatase increased. Protein repletion with algal and casein diets resulted in an increased activity of succinic dehydrogenase and alanine amino transferase and a decrease in alkaline phosphatase activity. However, the levels of these three enzymes were lower with the algal than with the casein diets. Algal diets regenerated serum protein effectively though to a slightly lesser extent than casein.  相似文献   

13.
Two rapeseed protein concentrates (RPC) supplemented with zinc oxide were fed to male and female rats at two levels providing approximately half or all of the protein in a purified basal diet containing 20% protein (N×6.25). Control groups were given either a purified basal diet with casein or a laboratory chow diet. After 16 weeks, there were no significant (P<0.05) differences in body weight except the male rats fed the casein control diet had higher body weights than did other male rats. No significant differences were observed in organ weights including thyroids, hematology, bone marrow differential counts, serum glucose, urea nitrogen, total protein, albumin/globulin ratio, cholesterol, transaminases or alkaline phosphatase. The levels of serum vitamins A and E of females fed some of the RPC diets were less than in those fed the caseincontrol diet, but equal to those in females fed laboratory chow diet. Females fed either RPC or casein in the semi-purified diets, which contained zinc oxide, exhibited kidney calcification.Bureau of Nutritional Sciences, No. 112; Food Research Institute, No. 420.  相似文献   

14.
Seafood is assumed to be beneficial for cardiovascular health, mainly based on plasma lipid lowering and anti-inflammatory effects of n-3 polyunsaturated fatty acids. However, other plasma risk factors linked to cardiovascular disease are less studied. This study aimed to penetrate the effect of a phospholipid-protein complex (PPC) from Antarctic krill on one-carbon metabolism and production of trimethylamine-N-oxide (TMAO) in rats. Male Wistar rats were fed isoenergetic control, 6%, or 11% PPC diets for four weeks. Rats fed PPC had reduced total homocysteine plasma level and increased levels of choline, dimethylglycine and cysteine, whereas the plasma level of methionine was unchanged compared to control. PPC feeding increased the plasma level of TMAO, carnitine, its precursors trimethyllysine and γ-butyrobetaine. There was a close correlation between plasma TMAO and carnitine, trimethyllysine, and γ-butyrobetaine, but not between TMAO and choline. The present data suggest that PPC has a homocysteine lowering effect and is associated with altered plasma concentrations of metabolites related to one-carbon metabolism and B-vitamin status in rats. Moreover, the present study reveals a non-obligatory role of gut microbiota in the increased plasma TMAO level as it can be explained by the PPC’s content of TMAO. The increased level of carnitine and carnitine precursors is interpreted to reflect increased carnitine biosynthesis.  相似文献   

15.
The aim of this study was to evaluate the protein quality of organic and genetically modified soy by feeding specific diets to rats. Three groups of Wistar rats (n = 10) were used, and each group was named according to the food that they ate. There was an organic soy group (OG), a genetically modified soy group (GG), and a control group (CG). All animals received water and diet ad libitum for 455 days. At the end of this period, the weight of the GG group was the same as that of the OG, and both were higher than CG. Protein intake was similar for the OG and GG, which were significantly lower (p < 0.0005) than the CG. The growth rate (GR) of the rats, albumin levels, and total levels of serum protein were comparable for all groups. Hematocrit (p < 0.04) and hemoglobin (p < 0.03) for the OG and GG were less than the CG. Although the OG and GG demonstrated reduced hematocrit and hemoglobin, both types of soy were utilized in a way similar to casein. This result suggests that the protein quality of soy is parallel to the standard protein casein in terms of growth promotion but not hematological indicators.  相似文献   

16.
The chemical compositions, of raw and treated lupine flour were determined and compared with other plant protein sources. The protein content in the dry matter was 47.7% in untreated seeds ofLupinus mutabilis and about 56% in debittered seeds. The oil-cake contained 65.3% protein. The amino acid analysis showed that lupine protein is characterized by a low level of S-amino acids, the content of which amounts to only 50% of that of the FAO standard reference pattern. The protein quality was measured using the biological tests PER (Protein Efficiency Ratio), NPU (net protein utilization), and BV (biological value) in rats on diets with and without DL-methionine supplementation. PER determinations gave low values for the non-supplemented lupine proteins (1.34, semi-sweet variety; 1.53, water-extracted seeds; 1.19, oil-cake; 3.09, casein), but the PER's were improved by the addition of 0.2% DL-methionine to the diets (3.05, 2.69, 2.81, respectively). Raw as well as processed lupine protein showed an excellent apparent digestibility (80.0–85.8%; casein, 87.1%). The observed NPU and BV values confirmed the importance of methionine supplementation. The true digestibility of 92% was equivalent to that of casein. The complementation effects of mixing lupine protein with proteins from wheat, oat, barley, rice, maize, potato, quinua or fish were investigated by determination of the PER values of the respective mixtures. Feeding lupine protein with cereal proteins resulted in PER values that exceeded by far those of the proteins fed separately (true complementation). This result was not observed for the mixture of potato and lupine. High quality proteins like quinua and fish protein also showed no complementation effect with lupine protein but did improve the quality of the lupine protein to a great extent. The best results could be obtained with combinations of three different plant proteins, in which lupine protein always contributed one third of total protein. These mixtures resulted in PER values equal to those for casein or other animal proteins and may be applied as an economical way to prevent and combat malnutrition.  相似文献   

17.
This study investigated the effects of chitosan oligosaccharide (COS) on glucose metabolism and hepatic steatosis in a high-fat (HF) diet/streptozotocin-induced diabetic rat model. Male Wistar rats were divided into: (1) normal control (NC group), (2) HF diet (HF group), (3) streptozotocin (STZ)-induced diabetes with HF diet (DF group), and DF group supplemented with (4) 0.5% COS (D0.5F group), (5) 1% COS (D1F group), and (6) 5% COS (D5F group) for 4 weeks. COS supplementation significantly decreased the plasma glucose, BUN, creatinine, uric acid, triglyceride (TG), and total cholesterol (TC) levels, and hepatic glucose-6-phosphatase activity, and significantly increased hepatic hexokinase activity and glycogen content in diabetic rats; but the increased hepatic TG and TC levels could not be significantly decreased by COS supplementation. Supplementation of COS increased superoxide dismutase activity and decreased lipid peroxidation products in the diabetic rat livers. COS supplementation significantly increased phosphorylated AMP-activated protein kinase (AMPK) protein expression, and attenuated protein expression of hepatic phosphoenolpyruvate carboxykinase (PEPCK) and phosphorylated p38 and renal sodium-glucose cotransporter-2 (SGLT2) in diabetic rats. These results suggest that COS may possess a potential for alleviating abnormal glucose metabolism in diabetic rats through the inhibition of hepatic gluconeogenesis and lipid peroxidation and renal SGLT2 expression.  相似文献   

18.
茶多酚对蛋鸡生产性能、脂类代谢及蛋品品质的影响   总被引：17，自引：0，他引：17  
本研究进行了两次饲养试验。试验一选用225羽37周龄罗曼蛋鸡随机分为5个处理,在试验基础日粮中分别添加0%、0.05%、0.1%、0.2%、0.4%茶多酚（纯度40%）,试验期59天;试验二选用600羽51周龄罗曼蛋鸡随机分为4个处理,分别在试验基础日粮中添加0%、0.025%、0.055%、0.1%茶多酚（纯度40%）,试验为期8周。探讨了茶多酚对蛋鸡生产性能、脂类代谢、蛋品质量的影响。结果表明：（1）日粮中添加不同剂量茶多酚对蛋鸡产蛋率和饲料利用率有一定的改善,但未见随茶多酚添加水平的升高而提高的趋势。（2）日粮中添加0.1%茶多酚可提高蛋黄中VE58.99%、VA20.96%,添加0.025%茶多酚降低蛋黄中胆固醇35.28%,茶多酚对全蛋中含硫氨基酸有增高趋势,重金属指标符合无公害鸡蛋要求;产蛋后期日粮中添加0.025%~0.1%茶多酚可降低破软蛋率31.59%~47.09%。（3）日粮中添加0.4%茶多酚分别降低46周龄蛋鸡血清总胆固醇19.65%、甘油三酯19.99%、低密度脂蛋白7.69%,提高高密度脂蛋白45.35%;但添加0.025%~0.1%茶多酚对59周龄蛋鸡血脂指标未见显著影响。  相似文献   

19.
Feeding of raw and heated soy flour (RSF & HSF) for 4 or 8 weeks to weanling swine was compared with feeding of casein diets. There was essentially no growth in pigs fed RSF, whereas body weight increased 4.5 fold over 8 weeks with either casein or HSF. No change in pancrease weight as percent body weight was found in any group in either experiment. Both total pancreatic RNA and DNA were decreased in RSF groups, although RNA and DNA/mg pancreas were increased by the RSF diets. Total pancreatic protein, as well as protein/mg, were decreased in RSF-fed pigs compared to casein and HSF. Pancreatic trypsin, chymotrypsin, lipase, and amylase, and fecal trypsin were decreased in RSF-fed pigs to varying degrees compared to either HSF or casein. HSF and casein performance was equivalent in all parameters measured. Results of these experiments are compared with results of feeding similar diets to rats and monkeys.  相似文献   

20.
The powder forms of soy-based infant formulas obtained from four manufacturers were fed to weanling rats for two weeks, as the sole source of protein in diets containing 8% protein, 20% fat, and adequate amounts of minerals and vitamins. The relative protein efficiency ratio (RPER) and the relative net protein ratio (RNPR) values (casein + methionine=100) of diets containing unsupplemented formulas were 71–81 and 78–85, respectively. Supplementation of the formula diets with lysine (0.2%), methionine (0.2%), threonine (0.1%) or tryptophan (0.05%) increased the level of the supplemental amino acid in rat serum but generally failed to improve the RPER or RNPR values. Addition of all four essential amino acids to the formula diets, however, caused a marked improvement in their protein quality (RPER or RNPR values=100). The data suggested that proteins in soy-based formulas could be marginally co-limiting in several indispensable amino acids.Presented in part at the 202nd annual meeting of the American Chemical Society, New York City, 25–30 August 1991.  相似文献   

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