Germfree mice reared on an "antigen-free" diet

Germfree mice were fed through three generations a water soluble, chemically defined, "antigen-free" diet with a supplement of oil and oil-soluble vitamins. Second generation animals were compared to germfree and specific-pathogen-free mice fed a natural-type commercial diet. The ceca of the germfree mice fed the antigen-free diet were smaller than those of germfree mice fed the natural-type diet but larger than those of specific-pathogen-free mice fed the natural-type diet. Their mean spleen size was between that of germfree and specific-pathogen-free mice fed the natural-type diet, but the differences were of borderline significance. Germfree mice fed the antigen-free diet had fewer leukocytes than the other groups. Their serum immunoglobulin G level was one-tenth that of germfree mice fed the natural-type diet and one-hundredth that of specific-pathogen-free mice fed the natural-type diet. Their serum immunoglobulin M was only slightly below germfree, natural-type diet levels. Immunoglobulin A could be detected in the intestinal wall and contents of specific-pathogen-free mice fed the natural-type diet but not in either of the germfree groups.     

Immunological state of adult germfree miniature minnesota pigs

Fundamental hematological and immunological data were obtained on sexually mature germfree miniature pigs fed, after the milk diet period, with cereal-type diet sterilized by γ-radiation, and were compared with data of control conventional animals. Germfree adult pigs had a lower count of peripheral blood leukocytes with a lower percentage of neutrophil granulocytes and without any younger forms, a lower total serum protein level with a negligible amount of γ and α₂ globulin fractions and a higher serum albumin and β globulin level. In the mesenteric lymph nodes and in spleen, surface IgA-bearing cells predominated over surface IgG-bearing cells. Also a large amount of IgA-containing cells was found in the intestinal lamina propria, where the IgG cells were present in a negligible amount. IgM cells were the most frequent surface isotype in peripheral blood. The count of blood T lymphocytes was more than doubled.     

Bacteriocin-producing strain of Enterococcus faecium EK 13 with probiotic character and its application in the digestive tract of rabbits

Enterococcus faecium EK 13 is a bacteriocin-enterocin A producing strain with probiotic properties. In this study its colonization, stability and effect on microflora in rabbits was studied as well as its influence on zootechnical parameters. Fifty rabbits of both sexes (HYPLUS, 30-day old; after weaning) were divided into control (CG) and experimental (EG) groups. They were fed a standard diet. Moreover, 25 rabbits in EG were fed daily (for 4 weeks) 15 g (separate doses ∼1.6 g) of lyophilized EK13 strain (rifampicin resistant variant — rif^R; 10⁹ cfu/g) dissolved in drinking water. After cessation of EK13 (rif^R) strain application, the rabbits in both groups were fed a standard diet for the next 2 weeks. Sampling was performed in double on day 0 (at the beginning of experiment), weekly during EK13 (rif^R) strain application as well as on week 1 and 2 after cessation of EK13 (rif^R) strain application. The counts of EK13 (rif^R) strain reached 7.1 ± 2.6 log₁₀ cfu/g after 4 weeks and even on week 2 after its cessation the counts 5.6 ± 2.3 log₁₀ cfu/g were determined. The total counts of enterococci in the rabbits were already increased in EG comparing with CG (p < 0.05); even 2 weeks after EK13 (rif^R) strain cessation, their counts in EG were 7.2 ± 2.6 log₁₀ cfu/g (p < 0.001). Enterococci in CG reached at the same time the value 3.7 ± 2.6 log₁₀ cfu/g. The counts of E. coli were significantly reduced in EG during 4 weeks (p < 0.05, p < 0.001). Even 2 weeks after EK13 (rif^R) strain cessation significant difference in E. coli counts between CG and EG was detected (p < 0.001). Enterobacteria in EG were significantly reduced (p < 0.001). Average daily gain in EG was 41.0 ± 3.83 in comparison to CG (40.6 ± 3.72); it means almost the same; although rabbits in EG showed higher feed intake per kg of gain than rabbits in CG. Preliminary results demonstrated that EK13 is a perspective probiotic candidate for rabbits. Presented at the Second Probiotic Conference, Košice, 15–19 September 2004, Slovakia.     

Physiological Response of Rabbit Bucks to Dietary Fumonisin: Performance,Haematology and Serum Biochemistry

Maize grains contaminated with fumonisin, a metabolite of Fusarium verticillioides was incorporated into matured male rabbits’ diet to evaluate its effects on performance, haematology and serum biochemistry in rabbits. Thirty individually caged crossbred adult rabbit bucks averaging 1.36 ± 0.01 kg (about 22–24-week-old) were randomly allotted to three treatment diets comprising a control diet (containing 0.35 ± 0.02 mg fumonisin/kg) and two test diets containing 12.30 ± 0.16 and 24.56 ± 0.14 mg fumonisin/kg, constituting treatments 1 (low infection), 2 (medium infection) and 3 (high infection), respectively, in a five-week feeding trial. Results showed that the dry matter intake (DMI) (g/rabbit) at the end of the feeding trial was significantly (P < 0.05) influenced. The DMI declined with increasing dietary fumonisin by a significant 80% and 95% (P < 0.05) for high and medium levels of dietary fumonisin, respectively, relative to the mean weekly DMI of 609.93 ± 45.08 g by rabbits fed diet with low level of fumonisin. The weekly weight gain tended to decrease with increased dietary fumonisin levels, while the haematological and serum biochemical components examined, were not statistically influenced among the diets when fed to male rabbits for a period of 5 weeks. Target audience: Livestock farmers, Feed millers, and Animal nutritionists.     

Oxidative modification of lipoproteins in hypertriglyceridemic patients and hypercholesterolemic rabbits in vivo

Many lines of evidence suggest that LDL is oxidized in vivo and that Ox-LDL is present in the artery wall. But the oxidation of VLDL and HDL in vivo has not yet been reported. In this study, the oxidative modification of serum LDL, VLDL, and HDL in patients with endogenous hypertriglyceridemia (HTG) and in serum of rabbits fed on high cholesterol diet were made. The serum LDL, VLDL and HDL were isolated by the density gradient ultracentrifugation. The oxidative modification of LDL, VLDL and HDL were identified by agarose eletrophoresis, absorbance at 234 nm and fluorescence of TBARS. The results showed that serum TC, TG and TBARS in the HTG group (n= 25) and in rabbits fed with a high fat diet (for 12 weeks, n = 8) were significantly higher than those of the corresponding control groups (normal subjects, n = 25; rabbits fed with a normal diet, n = 8; p < 0.01). The electrophoretic mobilities of LDL, VLDL and HDL were increased when compared with the controls, and absorbance at 234 nm and TBARS of LDL, VLDL and HDL in the HTG group and in the high fat diet rabbits were significantly higher than those of the controls (p < 0.01). These results suggest that not only LDL but also VLDL and HDL were oxidatively modified in vivo in the patients with HTG and in the rabbits fed with a high cholesterol diet.     

The Relationship between the Intestinal Microflora and the Effects of Diets containing Raw Navy Beans (Phaseolus vulgaris) on the Growth of Japanese Quail (Coturnix coturnix japonica)

S ummary : Japanese quail chicks died within a few days when fed diet containing raw navy beans, whereas a similar diet containing autoclaved beans supported normal growth. The diet containing raw beans was nonlethal to germfree quail chicks, but did not support such good growth as the heated bean diet. The effects of associating germfree quail on the raw bean diet with various combinations of 149 pure cultures of bacteria isolated from the intestines of ordinary quail have been studied. Strains of Escherichia coli were shown to be responsible for the lethal effects of the raw bean diet.     

Effect of a starter diet supplementation with mannan-oligosaccharide or inulin on health status, caecal metabolism, digestibility of nutrients and growth of early weaned rabbits

The effect of a dietary supplementation with mannan-oligosaccharide (MOS, Bio-Mos, Alltech Inc.) and inulin (Frutafit® IQ) on growth, health, and caecal traits was studied on 348 rabbits (Hyplus®), weaned at 25 days of age. Three hundred and thirty rabbits (110 per group) were used for the health status and growth performance trial, while 18 rabbits (six per group) were used for caecal metabolism evaluation at the age of 42 days of age. Three diets were formulated: C (control), M (0.3% MOS) and I diet (4% inulin). Digestibility of the diets was measured in 10 rabbits per group between 36 and 40 days of age. The control diet was fed to rabbits of the C group from weaning to 74 days of age (slaughter). Diets M and I were fed to rabbits of the respective group from weaning to 46 days of age, then were fed with control diet till slaughter. From 25 to 46 days of age, the weight gain was slightly higher in control rabbits ( P = 0.11), while no differences were recorded for the whole period. No differences among groups in the mortality, which was high due to an enteropathy-infected environment, were significant. The lowest morbidity ( P = 0.05) as well as the health risk index were recorded in rabbits fed the diet with inulin ( P = 0.03). After change of diet, the health risk index increased in the rabbits previously fed the diet with additives, thereby no significant differences in the health status were recorded for the whole period. Total caecal volatile fatty acids concentration was higher ( P < 0.01) and the pH ( P < 0.01) and ammonia concentration ( P = 0.01) lower in rabbits fed the inulin diet than in other rabbits. In these animals, acetate molar proportion was higher ( P = 0.01) and that of propionate as well as the propionate/butyrate ratio significantly lower than in other rabbits. Butyrate molar proportion was higher in rabbits fed the diet with MOS ( P < 0.01). In rabbits fed the inulin diet a higher activity of inulinase was recorded ( P < 0.001) than in other rabbits. A significantly lower digestibility of cellulose was observed in rabbits fed the diet with MOS. The results of our study suggest the importance of using inulin-type fructans in the nutrition of young rabbits. The higher health risk index of rabbits after change of diets indicates that prebiotics should be given for a longer time during the fattening period.     

The effects of nutritional status of rabbits and sheep on their resistance to the ticksRhipicephalus evertsi evertsi andR. appendiculatus

Rabbits and sheep were exposed to low-and high-protein diets and subsequently infested three times with adults ofRhipicephalus appendiculatus andRhipicephalus evertsi evertsi. The mean weight ofR.e. evertsi females which dropped from rabbits maintained on a high-protein diet decreased from 515.0±24.9 mg (naive) to 381.5±25.0 (second infestation) to 340.3±23.3 mg (third infestation) while the weight of ticks fed on animals which were exposed to a low-protein diet did not change significantly (2.7%). The mean weight of engorged females ofR. appendiculatus which completed their blood meal on rabbits (high protein) decreased from 520.9±31.8 (naive) to 369.3±39 mg (3rd infestation), a significant decrease of 29.1% compared to a 12.3% decrease in weight between the 1 st and 3rd infestation of females fed on animals on a low-protein diet.Rhipicephalus e. evertsi fed on sheep exhibited the same phenomenon. The mean decrease in weight of 4rd-infestation ticks which dropped from sheep fed lucerne was 26.2% compared to 16.6% for ticks from sheep which were fed on grass.Hosts maintained on a low-protein diet failed to acquire resistance to ticks, lost weight and developed anaemia while those on a high-protein diet developed resistance, maintained weight and did not develop anaemia.The nutritional stress of the hosts and its application in South Africa are discussed.     

Effects of Montmorillonite on Pb Accumulation,Oxidative Stress,and DNA Damage in Tilapia (<Emphasis Type="Italic">Oreochromis niloticus</Emphasis>) Exposed to Dietary Pb

In order to investigate the effects of montmorillonite (MMT) on reducing dietary lead (Pb) toxicity to tilapia (Oreochromis niloticus), 240 fish were randomly divided into four treatments denominated as follows: control treatment (fed with a basal diet), MMT treatment (fed with a basal diet added with 0.5% MMT), Pb treatment (fed with a basal diet added with 100 mg Pb per kilogram dry weight (dw)), and Pb + MMT treatment (fed with a basal diet added with 100 mg Pb per kilogram dw and 0.5% MMT). Changes in Pb accumulation, oxidative stress, and DNA damage in tilapia were measured after 60 days. DNA damage was assessed using comet assay. The results showed that MMT supplemented in diet significantly reduced Pb accumulation in kidney and blood of tilapia exposed to dietary Pb (P < 0.05). Malondialdehyde level decreased insignificantly while levels of total antioxidant capacity and glutathione (GSH), activities of glutathione peroxidase, and superoxide dismutase increased insignificantly in kidney of tilapia in Pb + MMT treatment as compared to Pb treatment (P > 0.05). Significant decreases in tail length, tail DNA, tail moment, and Olive tail moment of peripheral blood cells in Pb + MMT treatment were observed when compared with Pb treatment (P < 0.05). The results indicated that dietary MMT supplementation could alleviate dietary Pb toxicity to tilapia effectively.     

Pattern of cardiac fibrosis in rabbits periodically fed a magnesium-restricted diet and administered rare earth chloride through drinking water

It has been postulated that causation of the tropical cardiomyopathy endomyocardial fibrosis (EMF) is linked to magnesium (Mg) deficiency and cardiac toxicity of the rare earth element cerium (Ce). The aim of the present study was to define the myocardial lesions in rabbits that were fed on Mg-restricted diet (70–80 ppm) periodically and were provided drinking water contaminated with rare earth chloride (1 g/L). Forty New Zealand white rabbits were divided into four groups following a 2 × 2 factorial design. Two groups were periodically fed on Mg-restricted diet with one of them receiving water contaminated with rare earth chloride. The other two groups were continuously fed on Mgsufficient diet (350–400 ppm) with one of them receiving water contaminated with rare earth chloride. All animals were sacrificed at the end of 6 mo. Cardiac tissues were subjected to histology, elemental analysis (calcium [Ca], Mg, and Ce) and estimation of collagen content and collagen phenotypes. Histological lesions were compared with those of EMF in humans and those of acute Mg deficiency in animals. The results suggest that in rabbits, recurrent episodes of Mg deficiency lead to myocardial fibrosis similar to the pattern observed in human EMF.     

Difference in antibody production to hererologus erythrocytes in conventional, specific-pathogen-free (SPF), germfree and antigen-free mice.

The expression of antibody-producing capacities against hamster erythrocytes (HRBC), known to be weakly immunogenic in mice, was compared among conventional, SPF, germfree and antigen-free mice. ICR strain germfree and antigen-free mice showed antibody production to HRBC comparable to that in conventional or specific-pathogen-free (SPF) mice. In the NC strain, some of the conventional mice produced low titers of antibody after a single injection of HRBC, but none of the germfree mice showed such a transient antibody production. In the ICR-KIG strain, which was selected from the colony-bred ICR strain, antibodies with high titers were produced after a single injection of HRBC under both conventional and germfree conditions. The onset of conversion from 2-mercaptoethanol (2-ME) sensitive to 2-ME resistant antibody after a single injection of HRBC was not delayed in the germfree mice when compared with the conventional or SPF mice. Antibody production to sheep erythrocytes (SRBC), known to be highly immunogenic in mice, was not influenced by exogeneous stimulation from microorganisms or diet. No differences in antibody production to SRBC were detected irrespective of the maintenance conditions of the mice. Stimulation with microorganisms or diet may not be required as essential elements for the maturation of antibody-producing capacities, but such a stimulation appears to modify the antibody response. The modifying effect was more prominent in the antibody response against weakly immunogenic antigens than against highly immunogenic ones.     

Passage of foreign proteins across the intestinal wall of newborn rabbits

Foreign proteins penetrate across the wall of rabbit jejunum takes place within the first eight hours after birth. Sensitization by foreign protein (cow's milk protein) during early postnatal ontogeny is the cause of death of artificially fed germfree rabbits at the age of 21-23 d.     

Lymphatic tissue of the intestinal tract of germfree and conventional rabbits

The lymphatic tissue of ileum, sacculus rotundus and appendix was poorly developed with-out germinal centres in germfree rabbits; on the other hand, in conventional rabbits, the lymphatic tissue was abundant with numerous germinal centers. In germfree rabbits, the stroma of villi of the jejunum and ileum possessed low cellularity, in conventional rabbits, the villi were wide with rich cellularity. The basal position of lymphocytes was predominant in the villi of ileum of germfree rabbits, in conventional rabbits a high percentage of lymphocytes was in the apical position.     

The microbiome affects liver sphingolipids and plasma fatty acids in a murine model of the Western diet based on soybean oil

Studies in mice using germfree animals as controls for microbial colonization have shown that the gut microbiome mediates diet-induced obesity. Such studies use diets rich in saturated fat, however, Western diets in the United States America are enriched in soybean oil, composed of unsaturated fatty acids, either linoleic or oleic acid. Here, we addressed whether the microbiome is a variable in fat metabolism in mice on a soybean oil diet. We used conventionally-raised, low-germ, and germfree mice fed for 10 weeks diets either high or low in high-linoleic-acid soybean oil as the sole source of fat. Conventional and germfree mice gained relative fat weight and all mice consumed more calories on the high fat vs. low fat soybean oil diet. Plasma fatty acid levels were generally dependent on diet, with microbial colonization status affecting iso-C18:0, C20:3n-6, C14:0, and C15:0 levels. Colonization status, but not diet, impacted levels of liver sphingolipids including ceramides, sphingomyelins, and sphinganine. Our results confirm that absorbed fatty acids are mainly a reflection of the diet and that microbial colonization influences liver sphingolipid pools regardless of diet.     

Feeding responses of the red fox (<Emphasis Type="Italic">Vulpes vulpes</Emphasis>) to different wild rabbit (<Emphasis Type="Italic">Oryctolagus cuniculus</Emphasis>) densities: a regional approach

We investigate the feeding responses of the red fox (Vulpes vulpes) at a regional scale to different densities of European wild rabbit (Oryctolagus cuniculus) in central–southern Spain. Rabbit abundance indices were obtained in 86 localities during summer 2002. The diet of the fox was studied by analysis of 114 scats collected in 47 of these localities. The feeding response of the fox was examined by a representation of the dry weight percent of rabbit in the diet as a function of the abundance of rabbits; this used data only from those localities where at least 3 scats were collected (70 fox scats from 18 localities). We evaluated the relationship between rabbit abundance and the diversity of the diet of the fox. The feeding patterns of red foxes approximated to Holling’s type III functional response, typical of opportunistic predators. There was a negative relationship between the diversity of the fox’s diet and the abundance of rabbits. Therefore, the fox apparently behaves as a facultative predator, feeding on rabbits when they are abundant and shifting to other prey (and hence a more diverse diet) when rabbits are scarce. These findings are the first step towards understanding the potential role of red foxes in regulating rabbit populations in central–southern Spain.     

多沙唑嗪光学异构体对高血脂家兔血脂水平的影响

目的:观察左旋多沙唑嗪(-)DOX、右旋多沙唑嗪(+)DOX和消旋多沙唑嗪(±)DOX对高血脂家兔血脂水平及动物死亡率的影响。方法:取普通级雄性新西兰大耳白兔,给予高脂饮食4周后,血清TC小于10mmol/L的8只家兔为普通饮食组,饲以标准饲料。血清TC大于10mmol/L的40只家兔随机分为4组(n=10):高脂模型组、高脂模型+(-)DOX组、高脂模型+(+)DOX组以及高脂模型+(±)DOX组。普通饮食组和高脂模型组家兔腹腔注射无菌双蒸水;其他3组家兔分别腹腔注射(-)DOX、(+)DOX和(±)DOX,连续9周。分析药物对兔血清总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL-C)和低密度脂蛋白胆固醇(LDL-C)的影响。结果:饲以高脂饮食13周时模型组家兔死亡率达40%,远远高于普通饮食组家兔(10%),亦明显高于(±)DOX和(-)DOX处理组。模型组家兔随高脂饲养的时间延长,血清LDL-C水平进一步显著升高(P0.05和P0.01);而各药物处理组动物的血清LDL-C水平未显著升高(P0.05)。结论:(-)DOX和(±)DOX可提高高脂饮食家兔的生存率,并对高血脂家兔的血清LDL-C紊乱具有轻度的改善作用;该作用可能不是其提高高脂饮食家兔生存率的主要作用机制。     

Vitamin K deficiency of germfree mice caused by feeding standard purified diet sterilized by gamma-irradiation.

Germfree mice died when they were fed a purified diet of AIN-76 formula sterilized by gamma-irradiation. Vitamin K deficiency was suspected and this study was performed to confirm the cause of the death. Germfree mice were fed purified diets of AIN-76 or AIN-93M formula, which were pelleted and sterilized by gamma-irradiation at a dose of 50 kGy. One half of the mice fed the AIN-76 diet died within two weeks and the surviving animals were also in poor health, while 91% of mice fed the AIN-93M diet survived. No hemorrhage was observed grossly in any organs of the surviving animals. Histologically, degeneration with inflammatory cell infiltration was observed as well as hemorrhage and fibrosis in the heart muscles of mice fed the AIN-76 diet. No microscopic lesions were observed in the other organs. Prothrombin time (PT) and activated partial thromboplastin time (APTT) were extremely prolonged when mice were fed the AIN-76 diet. The animals totally recovered when they were intragastrically administered 1 microg/day of vitamin K(3) from the third day of feeding of the AIN-76 diet, except for PT and APTT which were still slightly longer than in mice fed the AIN-93M diet. The concentration of vitamin K(3) supplied in the AIN-76 diet decreased to an undetectable level after gamma-irradiation, while the AIN-93M diet contained 240 microg/kg of vitamin K(1). These results indicate that the deaths of the germfree mice fed the gamma-irradiated AIN-76 diet were caused by vitamin K deficiency. Vitamin K deficiency may cause fatal degeneration of cardiac muscle cells.     

Purification of adenylosuccinate lyase from rat skeletal muscle by a novel affinity column. Stabilization of the enzyme, and effects of anions and fluoro analogues of the substrate.

The turnover of prothrombin and of factor X was investigated in rabbits fed on a 1%-cholesterol-supplemented or a standard diet by studying the evolution of radioactivity in blood and in plasma from these animals after the intravenous injection of either 125I-rabbit factor X or 125I-bovine prothrombin. For factor X, half-lives and fractional pool sizes were similar for the two groups of rabbits in the extravascular, intravascular and plasma compartments. However, the equivalent plasma fractional pool size for the two groups of rabbits was only 73% of that in the intravascular compartment. The fractional catabolic rate for the hypercholesterolaemic rabbits [0.064 +/- 0.007 (of the intravascular pool)/h] was not significantly different from that in the rabbits fed on the standard diet (0.074 +/- 0.008/h). However, the absolute catabolic rate, and therefore the rate of synthesis, was significantly higher (1.261 +/- 0.141 mg/day per kg body wt. of rabbit) in the rabbits fed on the cholesterol-supplemented than that in the rabbits fed on the standard diet (0.705 +/- 0.019 mg/day per kg). The prothrombin half-lives and fractional pool sizes were similar for the two groups of rabbits in the extravascular and the intravascular compartments. The fractional catabolic rate for the hypercholesterolaemic rabbits [0.041 +/- 0.003 (of the plasma pool)/h] was not significantly different from that in the rabbits fed on the standard diet (0.035 +/- 0.003/h). However, the absolute catabolic rate and therefore the rate of prothrombin synthesis was significantly higher (3.96 +/- 0.48 mg/day per kg body wt.) in the rabbits fed on the cholesterol-supplemented than that in the rabbits fed on the standard diet (2.24 +/- 0.12 mg/day per kg).     

Effect of coconut oil on plasma apo A-I levels in WHHL and NZW rabbits

Age-matched Watanabe (WHHL) and New Zealand White (NZW) rabbits were fed a coconut oil-enriched diet (14%, w/w) for 2 weeks. Lipid and apolipoprotein (apo) A-I levels in plasma and lipoprotein fractions were monitored. Within 3 days after the start of the coconut oil diet, plasma apo A-I and high-density lipoprotein (HDL)-apo A-I levels increased 3-fold in the WHHL rabbits. A smaller but significant increase (63%) in apo A-I and HDL-apo A-I levels was also observed in the NZW rabbits. HDL cholesterol levels also increased from 16 +/- 3 mg/dl during a regular diet to 46 +/- 16 mg/dl (288%) during the coconut oil diet in the WHHL rabbits and from 37 +/- 7 mg/dl to 69 +/- 19 mg/dl (186%), respectively, in the NZW rabbits. Apo A-I and HDL cholesterol levels fell sharply to the original levels soon after switching back to a regular diet (within 3 days for WHHL rabbits and within 5 days for NZW rabbits). The fractional catabolic rate calculated from 125I-HDL kinetic studies indicated that the turnover rate for HDL was significantly slower in WHHL rabbits fed the coconut oil diet than the control diet (0.018 +/- 0.004 h-1 vs. 0.027 +/- 0.007 h-1, P less than 0.01). No changes were found in the NZW rabbits fed either diet. Trilaurin, the main component of the coconut oil (46.9%) supplemented diet (6.5%, w/w), was also used in this study. The effect of trilaurin on plasma apo A-I and HDL-cholesterol levels is discussed.     

脂负荷性饵食对家兔脂代谢的影响

目的探讨建立兔饵食性高脂血症模型的方法,观察高脂饮食对兔体重、死亡率及血脂变化情况。方法取普通级雄性新西兰大耳白兔,其中随机抽取10只作为普通饮食组,喂以普通饮食;其他动物给予高脂饮食,4周后,根据血清TC水平分为高脂饮食敏感组和高脂饮食非敏感组,继续喂养9周,观察三组间兔血清总胆固醇（TC）、甘油三脂（TG）、高密度脂蛋白胆固醇（HDL-C）和低密度脂蛋白胆固醇（LDL-C）的变化。结果与普通饮食组相比,高脂饮食敏感组在第4～13周时血清TC、TG、HDL-C、LDL-C水平显著升高（P〈0.01）,高脂饮食非敏感组在第7～13周时,动物血清TC、HDL-C、LDL-C水平显著升高（P〈0.01）,而高脂饮食非敏感组血清TG水平的改变无统计学意义（P〉0.05）。与高脂饮食敏感组相比,高脂饮食非敏感组家兔血清TC、TG、HDL-C和LDL-C水平的上升程度均显著低于高脂饮食敏感组动物（P〈0.01）。结论首次发现兔对高脂饮食敏感性存在差异,高脂饮食非敏感组家兔抗病能力、对环境的适应能力和耐受性均高于高脂饮食敏感组兔。与高脂饮食敏感组家兔相比,高脂饮食非敏感组家兔对高脂饮食耐受性强。