Micronucleus test in mice fed on an irradiated diet

A mutagenicity study was carried out in mice fed on a gamma-irradiated diet. As an indicator of mutagenic activity, we observed an incidence of micronuclei in erythrocytes. The average body weight of the mice fed on the diet irradiated to dose range of 400-1,000 kGy decreased, and the mice fed on the 800-1,000 kGy-irradiated diet died during the period from 8 to 14 days after the start of feeding. On the other hand, when the mutagenic activity of the irradiated diet was tested by observing occurrence of micronucleus in erythrocytes, no significant increase was recognized. These results indicated that the irradiated diet had no mutagenic activity, even though it possessed a toxic effect on the growth of mice.     

藤黄果提取物对高脂日粮诱导的大鼠部分组织中氨基酸谱的影响

为探讨藤黄果提取(-)-羟基柠檬酸(HCA)对高脂日粮诱导的大鼠部分组织器官中氨基酸谱的影响,选用100只雄性SD大鼠随机分成5组:普通日粮对照组,高脂日粮对照组,高脂日粮添加藤黄果提取物低剂量组、中剂量组和高剂量组,每组20只。高脂日粮组分别于日粮中添加相当于(-)-HCA的剂量为0,1 000,2 000和3 000 mg/kg的藤黄果提取物,饲养8周后采集静脉血,分离血清,取肝脏、腿肌等样品。试验结果表明:与普通日粮对照组比较,高脂日粮对照组中,大鼠体增重和BMI均极显著升高(P0.01)。与高脂日粮对照组比较,3个剂量的藤黄果提取物处理均可极显著降低大鼠的体增重(P0.01);低剂量组中肝糖原含量显著升高(P0.05),高剂量组肌糖原含量显著升高(P0.05),但对血糖浓度无显著性影响(P0.05);血清中T3和T4含量在高剂量处理组均显著升高(P0.05),血清瘦素含量在低剂量组显著升高(P0.05),而血清中胰岛素的含量则无显著变化(P0.05)。氨基酸组成分析结果表明:在血清中,藤黄果提取物处可以显著升高血清中部分生糖氨基酸的含量,支链氨基酸中异亮氨酸(Ile)及芳香族氨基酸色氨酸(Trp)的含量(P0.05);在肝脏中,藤黄果提取物可以显著降低肝脏组织中大部分生糖氨基酸和芳香族氨基酸的含量(P0.05),而对肝脏中支链氨基酸的影响不显著(P0.05);在腿肌中,(-)-HCA处理可显著降低生糖氨基酸的含量(P0.05),可以极显著降低支链氨基酸的含量(P0.01),同时(-)-HCA可以极显著降低芳香族氨基酸的含量(P0.01)。以上结果表明,藤黄果提取物通过改变大鼠血清中激素的含量、降低肝脏和肌肉中生糖氨基酸的含量,提高机体糖代谢的水平,达到抑制大鼠体重增加的效果。     

Growth,behavioural, serum biochemical and morphological changes in female rabbits fed high-fat diet

This study aimed to determine whether high-fat diet (HFD) could cause growth, behavioural, biochemical and morphological changes in young female rabbits. Thirty-six female rabbits were randomly divided into two groups fed with either a high-fat diet (HFD) or a standard normal diet (SND) for 5 weeks. Growth and behavioural changes were recorded during the 5-week feeding period. Tissue samples, including blood and adipose tissue, were obtained after slaughter. HFD rabbits weighed more by the end of the feeding period, had a higher percent body weight and adipose tissue weight change and had longer body and bust lengths than SND rabbits. HFD rabbits significantly reduced their feed intake and feeding frequency during the fourth and fifth weeks. HFD rabbits also showed lower frequency of drinking and resting and increased stereotypical behaviour. Besides, HFD rabbits showed significant physiological abnormalities. HFD rabbits had higher serum cholesterol (TC) and triglycerides (TG) levels than SND rabbits at the end of the feeding period, and higher free fatty acid (FFA) levels than rabbits in the SND group after the third week of feeding. Serum thyroxine (T4) increased significantly in week 2 and week 5 and triiodothyronine (T3) increased significantly in week four. However, there was no significant change in serum glucose (GLU) and insulin (INS) levels. Additionally, HFD reduced the area and diameter of perirenal and subcutaneous fat cells and increased their density. Our findings suggest that HFD rabbits had higher weight gains, accumulation of fat, and more behavioural changes than SND rabbits. Although high levels of fat in the diet had a low impact on hyperglycaemia, it could lead to hyperlipidemia and hyperthyroidism. Our results also suggest that sustained HFD may cause the proliferation of adipocytes in young female rabbits.     

Effect of capsaicin on cholecystokinin and neuropeptide Y expressions in the brain of high-fat diet fed rats

Capsaicin, one of the pungent principles of hot pepper, has been reported to cause a cessation of increases in body weight and fat gain induced by high-fat feeding. Especially, in body weight and feeding control, cholecystokinin (CCK) has been well known as a satiety signal and neuropeptide Y (NPY) has been described as one of the most potent orexigenic signals. This study was carried out to investigate the effect of capsaicin on CCK- and NPY- immunoreactivities (IR) in the brain of high-fat fed rats. The animals were divided into normal-fat diet (NF), high-fat diet (HF) and high-fat diet containing capsaicin (HF-CAP) groups. Mean body weight gain (MBWG) of HF group was higher than that of NF group. However, in HF-CAP group, MBWG was lower than that of HF group. CCK-IR in suprachiasmatic nucleus (SCN), paraventricular nucleus (PVN), median eminence (ME), arcuate nucleus (ARC) and amygdala was not prominent in all the groups. In cerebral cortex, CCK-IR was more reduced in HF-CAP group than in the other groups. In the HF-CAP group, NPY-IR in the hypothalamic nuclei, amygdala and cerebral cortex was more poorly found than in the NF and HF groups. It is concluded that (1) NPY-IR may react more sensitively on capsaicin than CCK-IR, (2) no rapid increase of body weight in capsaicin treated rats may result from the diminished food intake through the low expression of NPY in hypothalamus in HF-CAP group.     

Bile acid extraction rate in the liver of cows fed high-fat diet and lipid profiles in the portal and hepatic veins

The purposes of this study are to assess the responses of increased supplemental dietary fat in the cow, without upsetting rumen fermentation, on the bile acid (BA) extraction rate in the liver and to determine whether this diet would affect the postprandial lipid profiles in the portal and hepatic venous blood. Six Holstein cows were equipped with catheters fitted in the portal and hepatic veins. Two cows each were assigned randomly to a sequence of three dietary treatments of 21-day period. The methodology of this study was based on the supplementation of the basal concentrate diet with 0 (control), 5, or 10% calcium salts of fatty acids (CSFA). The total bile acids were significantly increased in the portal and hepatic veins with the 5% CSFA diet, whereas no increase occurred with the 10% CSFA diet. Data obtained in this study showed that 10% CSFA diet failed to stimulate BA secretion to exceed the values obtained with 5% CSFA-diet. Moreover, there was no change in the hepatic extraction rate of BA in animals fed either the 0 or 5% CSFA diets which ranged from 2.4 to 6.5-fold and 3.1 to 7.3-fold, respectively. However, the extraction rate increased sharply with the 10% CSFA diet (27-fold). The median portal and hepatic concentrations of total lipids, triglycerides, total cholesterol, phospholipids and non-esterified fatty acids did not show any significant increase during feeding of the control diet. Moreover, feeding either the 5 or 10% CSFA diet did not significantly increase these values in either vein.     

Effects of protein and carbohydrate sources on digestibility and digesta flow rate in weaned pigs fed a high-fat, dry diet

Two trials were conducted to evaluate the effects of protein source (48% CP soybean meal or casein) and carbohydrate source (25% dextrose or 25% lactose) on digestibility and digesta flow rate in early-weaned pigs. Diets contained 10% crude soybean oil and were formulated to contain 3.5 g lysine, 2.3 g Ca and 2.0 g P per 1,000 kcal DE of diet. In Trial 1, nutrient digestibility was greater for older than for younger pigs. Apparent digestibilities for energy, DM, CP and fat were lower (P less than .08) for younger and older pigs fed soybean meal rather than casein. Digestibility of soluble carbohydrates was less (P less than .02) for younger pigs fed soybean meal rather than casein as a protein source. Fat digestibility was lower (P less than .05) in younger pigs fed dextrose than in pigs fed lactose. A protein X carbohydrate source interaction (P less than .01) existed for fat digestibility by older pigs. In Trial 2, pigs were euthanatized, and digestibilities anterior to the ileum and the colon (pre-ileal and pre-cecal) were determined. At the ileum, fat digestibility was lower (P less than .05) for pigs fed soybean meal, whereas CP digestibility was lower (P less than .05) for pigs fed either soybean meal or dextrose. A protein X carbohydrate interaction was observed for ileal digestibilities of DM (P less than .06) and total carbohydrates (P less than .03) with lowest values obtained for the soybean meal plus dextrose diet. For casein diets, digestibility values were similar between the two carbohydrate sources.(ABSTRACT TRUNCATED AT 250 WORDS)     

沙棘果对高脂膳食大鼠肝脏脂代谢的影响

为了研究沙棘果对高脂膳食大鼠肝脏脂代谢的影响,以60只雄性Wistar大鼠为研究对象,随机分为5组,对照组、高脂模型组、沙棘果低、中和高剂量组。对照组给予基础饲料,其余各组给予高脂饲料喂养,同时试验组每日用不同浓度的沙棘果匀浆液灌胃大鼠。4周后处死动物,采集肝脏,分别测定肝脏脂质、脂代谢相关酶及抗氧化指标,光镜下观察肝脏组织病理改变。结果:沙棘果匀浆液可显著降低肝脏总胆固醇(TC)水平,增加高密度脂蛋白(HDL-C)水平;使肝脏组织总脂酶(LPS)、肝脂酶(HL)和脂蛋白脂酶(LPL)活性增强,MDA生成量减少。结论:沙棘果可降低高脂膳食大鼠肝脏脂质水平,提高肝脏脂代谢酶活性,增强抗氧化能力,减缓肝细胞的脂质过氧化。     

Fat source affects growth of weanling rats fed high-fat diets low in zinc

In two 3-week experiments with a 2-factorial design, weanling rats were fed semi-purified diets in which the zinc concentration was either suboptimal or adequate for maximum growth. In experiment 1, one low-fat diet and four diets enriched with 26% beef tallow (BT), butterfat (BF), coconut oil or sunflower oil (SF) were compared. The low-Zn SF diet did not support growth. The animals fed the high-Zn SF diet had the lowest final weights among all other groups, and their serum and femur Zn concentrations were markedly depressed. In experiment 2, the low- and high-Zn diets were enriched with 18% BT, SF, BT + SF (1:1 w/w), or olive oil (OL). Final live weights showed a Zn × fat source interaction. The low-Zn SF and OL groups consumed less food and weighed less than the low-Zn BT group. At the high-Zn level, final weights were comparable among groups. Serum and femur Zn concentrations did not significantly vary among groups fed diets with the same Zn level. Possibilities for the growth-retarding effect of the diets rich in unsaturated fatty acids (SF and OL) are discussed. Metabolic studies are needed to clarify the observed zinc × fat source interaction.     

The plasma level of triacylglycerols in horses fed high-fat diets containing either soybean oil or palm oil

The influence of dietary soybean oil versus palm oil on the plasma level of triacylglycerols was determined in a crossover experiment with four horses. Based on published data for humans and laboratory animals it was expected that a diet rich in unsaturated fatty acids in the form of soybean oil compared to saturated fatty acids in the form of palm oil would lower the plasma triacylglycerol level. The feeding of soybean oil versus palm oil for a period of four weeks did not change the level of plasma triacylglycerols in horses. Mean levels of triacylglycerol, free fatty acids and 3-hydroxybutyrate were 0.17 (SE, 0.04), 0.44 (SE, 0.063) and 0.16 (SE, 0.008) mmol/l, respectively. The fatty acid composition of the plasma triacylglycerols reflected the fatty acid composition of the diets. The activity of lipoprotein lipase was not different between the treatments. It is concluded that, under the present experimental conditions, the feeding of soybean oil to horses does not affect triacylglycerol secretion into plasma and thus does not influence the concentration of plasma triacylgycerols, when compared to the feeding of palm oil.     

高脂诱导非酒精性脂肪肝对CYP2A5表达的影响

为了研究高脂诱导脂肪肝对CYP2A5表达的影响,选取雄性C57BL/6J小鼠18只,随机分成对照组(control)、高脂组(NAFLD)和阳性对照组(PYR),每组6只,分别饲喂基础饲料和高脂饲料,阳性对照组饲喂基础饲料在处死前一天给予吡唑诱导,连续8周后小鼠断颈处死,取肝脏测定mRNA,CYP2A5的蛋白表达和酶活性。其结果阳性对照组CYP2A5的mRNA、蛋白表达和酶活性与对照组相比分别增加229%、80%、151%差异极显著(P0.01)。高脂诱导组与对照组相比CYP2A5的mRNA、蛋白表达和酶活性分别增加69%、34%、43%(P0.01)。表明高脂诱导非酒精性脂肪肝可增加CYP2A5的mRNA、蛋白表达水平和酶活力。     

The effect of cellulase on calves fed an acidified milk diet]

The purpose of this research was to establish the influence of 3 j Cx cellulase applied per gram of COT concentrate mixture, fed in combination with a milk diet acidified by formic acid to the value of pH 4.6, on calf growth performance in one metabolism and two field experiments. In the metabolism experiment two groups of calves, with six animals in each, were fed acidified whole milk, which was diluted stage by stage till weaning at 60 days of age. The average live weight gain in the control at the end of the milk feeding period, i.e. from 14 to 60 days of age, was 29.90 kg. This corresponds to a daily live weight gain of 0.650 g. The total live weight gain of male calves in the experimental group was 29.30 kg, corresponding to a daily live weight gain of 0.638 g (Tab. I). Tab. II shows the average feed and nutrient intakes per kg live weight gain. The calves which received the enzyme supplement tend to have the higher feed conversion rate. During the forage feeding period, i.e. from 61 to 90 days of age, the average daily live weight gains were 1.10 kg and 0.980 kg in the control and experimental groups, respectively (Tab. III). The average live weight of 90 days old male calves was 107.70 kg and 103.90 kg in the control and experimental groups, respectively. The amount of consumed nutrients (digestible protein and starch units); in relation to the total feed intakes, is lower in the experimental groups, which proves the higher feed conversion rate (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Hypokalaemic episodic polymyopathy in cats fed a vegetarian diet

A previously undocumented hypokalaemic condition with a cyclical nature, comprising acute bouts of polymyopathy followed by spontaneous recoveries, is described in the cat. Cats being fed a high protein vegetarian diet developed recurrent episodes of polymyopathy, characterised by ventroflexion of the head and neck, stiff forelimb gait, lateral head-resting and generalised muscle weakness. Plasma potassium concentrations (mean +/- standard deviation) were reduced from 3.28 +/- 0.33 mmol/l at the beginning of the experiment to 2.45 +/- 0.24 mmol/l during bouts of myopathy. This hypokalaemia was associated with increased creatine kinase activities indicative of muscle damage, and decreased urinary potassium concentrations, and was caused by insufficient dietary potassium. Cats that received the same diet supplemented with potassium did not develop hypokalaemic polymyopathy. Spontaneous recoveries of affected cats were not associated consistently with increases in plasma potassium concentrations. Plasma taurine concentrations decreased and glutamic acid increased markedly in all cats fed the experimental diet. There was no evidence of thiamin deficiency associated with the high glutamic acid intake. Veterinarians should be aware that hypokalaemic cats, and in particular those on potassium-deficient diets, may show cyclical disease with episodes of polymyopathy recurring after periods of spontaneous clinical recovery. This condition in cats may be a useful animal model for familial hypokalaemic periodic paralysis in humans.     

Septicemic salmonellosis in two cats fed a raw-meat diet

Salmonella gastroenteritis and septicemia were diagnosed in two cats presented for necropsy. Both cats resided in the same household and were fed a home-prepared, raw meat-based diet. Salmonella was isolated from multiple organs in both cats and from samples of raw beef incorporated into the diet fed to one of the cats. Subtyping of the bacterial isolates yielded Salmonella newport from one cat and from the diet it had been fed. This report provides evidence that the practice of feeding raw meat-based diets to domestic cats may result in clinical salmonellosis.     

Histological intestinal alterations in chickens fed low protein diet

To demonstrate whether that hypotrophied histological alterations of intestinal villi and epithelial cells are observed in chickens fed low crude protein (CP) diet, 36 male chickens were allotted into 10%, 16% and 22% CP diets groups for 35 days. The 10% CP group showed a lower value of weight gain and feed efficiency than the other two CP groups (p < 0.05). On the relative weight of visceral organs, the 10% CP group showed a heavier gizzard than the 22% CP group, a heavier jejunum than the other two CP groups and a heavier value of ileum and caeca than the 22% CP group (p < 0.05). On the relative length of intestines, the 10% CP group showed a longer value of duodenum and caeca than the other two CP groups, a longer jejunum than the 16% CP group and a longer colon than the 22% CP group (p < 0.05). The villus height and villus area of all intestinal segments did not change in all groups. The duodenal cell areas and cell mitosis numbers tended to be lower in 10% CP group than in the other two protein groups, and the jejunal cell area and duodenal cell mitosis numbers were decreased in the 10% crude protein group (p < 0.05). In relation to the protuberated cells in the higher CP groups, the 10% CP group showed only faintly protuberated cells on the duodenal and jejunal villus apical surface. The ileal villi did not show specific alterations among each group. The chronic feeding of low CP diet induced a hypotrophied histological alteration. This suggests that the hypotrophied histological alterations can assess that the fed‐diet is not so well‐balanced diets, nutritionally.     

Reduction of allergic symptoms in NC/Jic Jcl mice fed a diet containing casein phosphopeptide preparation, CPP-III

The effect of a commercially available dietary casein phosphopeptide preparation, CPP‐III, consisting mainly of bovine αs2‐casein (1–32) and β‐casein (1–28) on the development of allergic symptoms mediated by IgE antibody was investigated in NC/Jic Jcl mice. No significant difference was observed in the change in mean bodyweight between mice given a diet of a mixture of ovalbumin and CPP‐III (CPP‐III‐added diet) and those given a diet of ovalbumin alone (control diet) as a protein source. Total allergic score of five mice given the CPP‐III‐added diet was less than half that of those given the control diet for 13 weeks. Levels of intestinal total and ovalbumin‐specific immunoglobulin (Ig)A were significantly higher in the CPP‐III‐added diet group than in the control diet group, while the serum ovalbumin‐specific IgE level was significantly smaller in the former. The production of interleukin (IL)‐6 by spleen cells from mice that ingested the CPP‐III‐added diet for 13 weeks was obviously higher than that by spleen cells from mice administered the control diet, while the formation of IL‐4 by spleen cells from the former mice was significantly lower than that by the latter mouse. These results suggest that the oral ingestion of CPP‐III may be beneficial in reducing allergic symptoms mediated by IgE antibody.     

Changes in lipoprotein composition in horses fed a fat-supplemented diet

This study was designed to compare the effects of a fat-supplemented diet versus a traditional diet on the lipoprotein (LP) content in horses. In the first of two trials, eight two-year old horses were fed a basal diet, in which 80% of the digestible energy was supplied as chopped alfalfa hay. One group of four horses (fat-supplemented group, FS) was fed the remaining 20% of the digestible energy as corn oil, while the other group of four horses (control) was fed rolled corn to complete their diet. Blood samples were collected at the start of the experiment and every 2.5 weeks thereafter for 10 weeks. Total serum lipids were measured in both groups of horses and the lipoproteins were fractionated into very low density LP (VLDL), low density LP (LDL), and high density LP (HDL) using ultracentrifugation and agarose-column chromatography. Each LP fraction was measured for protein, cholesterol (CH) and triglyceride TG) content. Total serum lipids were increased in the FS group above the control (9.16 vs. 4.65 mg/ml, week 5). Serum cholesterol and triglyceride concentrations were elevated in the FS group, but were highly variable. Variations in lipid concentrations may have been due to variation in time of sampling during the day. In the second trial, four of the eight horses were used and divided into the same two groups; FS vs. control. After an initial sample, postprandial serial blood samples (1 hour intervals for 8 hours) were drawn at 2, 4 and 6 weeks. Upon examination of the data, Hour 3 post-feeding was chosen to represent postprandial LP values. In both trials, the horses were able to adapt to the added dietary fat. Maintenance of body weight and increased speed of lipid clearance from the blood by the end of each trial in the FS group support this statement. In the FS group, there was an increase in VLDL TG concentration, but not in LDL. This indicates an increase in VLDL TG clearance from the circulation, presumably by increased lipoprotein lipase (LPL) activity. Cholesterol concentrations were also increased in the FS horses in the LDL and HDL. The rise in cholesterol may be attributed to endogenous recycling of liver products such as bile salts, which aid in digestion and absorption and are cholesterol based. In addition, there were greater quantities of LDL and HOL produced in the FS horses as supported by the increased protein concentrations as well as larger peaks for the eluate from the gel filtration column.