孕哺期高脂膳食对子代SD大鼠血尿酸水平的影响

目的 探索孕哺期高脂膳食对子代SD大鼠血尿酸的影响。方法 10只成年雌性SD孕鼠随机分为对照组和高脂组,分别饲以标准鼠粮和含20%猪油的高脂饲料。4周龄断乳后,对照组雄性仔鼠中10只维持标准鼠粮(B/B),10只转饲以高脂饲料(B/HF);高脂组雄性仔鼠中10只维持原饲料(HF/HF),10只转饲以标准鼠粮(HF/B)。至12周龄,称量体重,测定血尿酸水平及黄嘌呤氧化酶和腺苷脱氨酶活性。结果 HF/HF组仔鼠体重、血尿酸水平及黄嘌呤氧化酶(xanthine oxidase,XOD)活性均显著高于B/B组及HF/B组(P＜0.05),HF/B组仔鼠血尿酸水平及XOD活性高于B/B组(P＜0.05),血ADA活性各组间差异无统计学意义(P>0.05)。结论 孕哺期高脂膳食可对子代高尿酸血症的发生产生影响,断乳后膳食调整可减弱其影响,机制可能与血黄嘌呤氧化酶活性的改变有关。     

Lipid profile of rats fed high-fat diets based on flaxseed, peanut, trout, or chicken skin

OBJECTIVE: Dietary saturated fatty acids are associated with coronary disease. Conversely, dietary monounsaturated polyunsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) seem to exert a protective effect. This study evaluated the lipid profile of rats fed high-fat (HF) diets, with fat added as different sources of PUFA (flaxseed and trout), MUFA (peanut), and saturated fatty acid (chicken skin). METHODS: Adult male Wistar rats were placed into six dietary groups (n = 10): control (normal); high fat, with 1% cholesterol, 10% soy oil, and 5% lard; and four groups fed similar HF diets, with 10% lipid as trout, flaxseed, peanut, or chicken skin. After 28 d the animals were killed. Blood, livers, and adipose tissue samples were collected. RESULTS: A higher level (P < 0.05) of total serum cholesterol was observed in rats fed the normal diet (93.57 +/- 14.95 mg/dL) compared with those fed the HF diet (67.57 +/- 12.54 mg/dL). Total cholesterol levels in rats fed the flaxseed diet were lower (P < 0.05) than in rats fed the other fats. No difference was observed in cholesterol levels between groups fed the peanut and chicken skin diets (P > 0.05). Animals fed the peanut diet showed decreased body weight gain than did animals in the other treatment groups. There were large lipid and cholesterol depositions in livers of rats fed the HF diet. Lipid deposition in adipose tissue followed the same dietary fatty acid profile, i.e., high levels of omega-3 PUFA in the flaxseed group, high levels of MUFA in the peanut and chicken skin groups and high levels of omega-6 PUFA in the trout group. CONCLUSIONS: These data indicate that flaxseed is promising for dietary manipulation of hyperlipidemia.     

Effects of dietary fatty acids and exercise on body-weight regulation and metabolism in rats

OBJECTIVE: To assess the interaction of high-fat diets (HF) made with different dietary fatty acids and exercise on body-weight regulation, adiposity, and metabolism. RESEARCH METHODS AND PROCEDURES: Male Wistar rats born to dams fed HF diets (40% w/w) made with either fish oil (FO), soybean oil (SO), or palm oil (PO) were fed diets similar to their dams and divided randomly into exercise (EX, swimming) or sedentary control (SD) groups when they were 9 weeks old. EX lasted for 6 weeks. Twenty-four hours after the last EX bout, fasted rats were killed by decapitation. Chemical analyses and body composition analysis were conducted. RESULTS: The results demonstrated that different fatty acids had different effects on body weight, composition, and metabolism. SO-fed rats gained the most weight and fat. EX reduced body weight of FO- and PO-fed rats, but SO-fed rats were still heavier and fatter than other rats. Data from SO- and PO-fed rats suggested that they are insulin resistant and that EX normalized this abnormality. Of the three HF diets used, FO produced the least adverse effects compared with PO and SO. DISCUSSION: Not only the quantity of dietary fat, but also the type of fat used, will produce different effects on body weight and metabolism. EX ameliorates the suggested insulin resistance induced in rats fed either highly saturated or n-6 polyunsaturated fatty acids. Long-chain n-3 polyunsaturated fatty acids, as found in fish oil, are more beneficial than n-6 polyunsaturated fatty acids when fed in high amounts to rats.     

Insulin insensitivity is rapidly reversed in rats by reducing dietary fat from 40 to 30% of energy.

The objective of this study was to determine the effect of reducing dietary fat content from 40 to 30% of total energy on body composition and insulin sensitivity in rats. Female Sprague-Dawley rats were fed either a control diet (30% energy as fat) or a high fat diet (40% energy as fat) for 10 wk. In vivo glucose tolerance tests indicated that both basal and glucose-stimulated insulin concentrations were elevated in rats fed the high fat diet. Two groups of rats offered the high fat diet were then fed the control diet (HF,C) and two that had received the high fat diet were then fed a diet (30% energy as fat) containing a fat-mimetic carbohydrate (HF,M). Two groups continued to receive the high fat diet and two groups continued to receive the control diet. Rats were killed 1 and 2 wk after the diet switch. In vivo glucose tolerance tests indicated that insulin sensitivity was corrected in HF,C and HF,M rats after 3 d. Body fat content was greater in rats fed the high fat diet and remained high after 7 d of consuming either diet with 30% of energy from fat. There was no effect of diet on liver fatty acid utilization or on diaphragm glucose oxidation. Adipocytes from all treatment groups were insulin resistant, possibly due to feeding status or age of the rats. The results of this study suggest that a moderate reduction in fat intake, from 40 to 30% of energy, can produce a rapid improvement of insulin sensitivity in insulin-insensitive rats, independent of changes in body fat content and irrespective of the means used to reduce dietary fat content.     

Influence of Dietary Fats Upon Systolic Blood Pressure in the Rat

Studies were performed to determine whether feeding diets with differing fatty acid content and composition had an influence on systolic blood pressure in the rat. Weanling male rats were fed standard laboratory chow (2.9% fat in total), or synthetic diets (10% fat in total) containing fish oil, butter, coconut oil or corn oil, for 5 weeks. Coconut oil and butter diets were rich in saturated fatty acids, whilst fish oil and corn oil were rich in the n-3 and n-6 unsaturated fatty acids respectively. Systolic blood pressure was measured using an indirect tail-cuff method at the end of the feeding period, and compared to a group of weanling rats.

Feeding the different diets did not alter the growth of the rats, so all animals were of similar weights at the time of blood pressure determination. Control (chow fed) animals, at nine weeks of age, had higher systolic blood pressures than the weanling, baseline control group. Fish oil fed rats had similar pressures to the chow fed rats. Corn oil fed rats had significantly lower systolic pressures than the controls. The rats fed the diets rich in saturated fatty acids (butter and coconut oil) had significantly higher blood pressures than all other groups. Systolic blood pressure was found to be significantly related to the dietary intakes of saturated and unsaturated fatty acids. The dietary intake of linoleic acid was significantly higher in corn oil fed rats than in other groups. Systolic blood pressure was inversely related to linoleic acid intake. Feeding a diet rich in saturated fatty acids significantly increases blood pressure in the rat. A high intake of n-6 fatty acids, and in particular linoleic acid, appears to have a hypotensive effect. Prenatal exposure of the rats to a maternal low protein diet, abolished the hypertensive effects of the coconut oil diet and the hypotensive effect of the corn oil diet upon young adult females. The intrauterine environment may, therefore, be an important determinant of the effects of these fatty acids on blood pressure in later life.     

High dietary calcium reduces body fat content,digestibility of fat,and serum vitamin D in rats

OBJECTIVE: This study investigated which aspect of energy balance was responsible for the decrease in body fat content of rats fed a high-calcium, high-dairy protein diet. RESEARCH METHODS AND PROCEDURES: Male Wistar rats were fed a control diet (25% kcal fat, 14% kcal protein from casein, 0.4% by weight calcium) or high-calcium diet (25% kcal fat, 7% kcal protein from nonfat dry milk, 7% kcal protein from casein, 2.4% calcium) for 85 days. Body weights, digestible energy intakes, energy expenditures, rectal temperatures, body composition, and serum glucose, insulin, free fatty acids, triglycerides, and 1,25-dihydroxyvitamin D were measured. RESULTS: Rats fed high-calcium diet gained significantly less weight than controls and had 29% less carcass fat. Gross energy intake was not significantly different between groups, but digestible energy was 90% of gross energy in the high-calcium diet compared with 94% in the control diet because of increased fecal excretion of dietary lipid. The difference in digestible energy intake accounted for differences in carcass energy. Body temperatures and energy expenditures of the rats were not different. The high-calcium diet reduced serum triglycerides by 23% and serum 1,25-dihydroxyvitamin D by 86%. DISCUSSION: These results confirm that a high-calcium diet decreases body weight and fat content due to a lower digestible energy intake caused by increased fecal lipid and a nonsignificant reduction in gross energy intake.     

beta3-adrenoceptor agonist prevents alterations of muscle diacylglycerol and adipose tissue phospholipids induced by a cafeteria diet

BACKGROUND: Insulin resistance induced by a high fat diet has been associated with alterations in lipid content and composition in skeletal muscle and adipose tissue. Administration of beta3-adrenoceptor (beta3-AR) agonists was recently reported to prevent insulin resistance induced by a high fat diet, such as the cafeteria diet. The objective of the present study was to determine whether a selective beta3-AR agonist (ZD7114) could prevent alterations of the lipid profile of skeletal muscle and adipose tissue lipids induced by a cafeteria diet. METHODS: Male Sprague-Dawley rats fed a cafeteria diet were treated orally with either the beta3-AR agonist ZD7114 (1 mg/kg per day) or the vehicle for 60 days. Rats fed a chow diet were used as a reference group. In addition to the determination of body weight and insulin plasma level, lipid content and fatty acid composition in gastronemius and in epididymal adipose tissue were measured by gas-liquid chromatography, at the end of the study. RESULTS: In addition to higher body weights and plasma insulin concentrations, rats fed a cafeteria diet had greater triacylglycerol (TAG) and diacylglycerol (DAG) accumulation in skeletal muscle, contrary to animals fed a chow diet. As expected, ZD7114 treatment prevented the excessive weight gain and hyperinsulinemia induced by the cafeteria diet. Furthermore, in ZD7114 treated rats, intramyocellular DAG levels were lower and the proportion of polyunsaturated fatty acids, particularly arachidonic acid, in adipose tissue phospholipids was higher than in animals fed a cafeteria diet. CONCLUSIONS: These results show that activation of the beta3-AR was able to prevent lipid alterations in muscle and adipose tissue associated with insulin resistance induced by the cafeteria diet. These changes in intramyocellular DAG levels and adipose tissue PL composition may contribute to the improved insulin sensitivity associated with beta3-AR activation.     

Glucosamine attenuates increases of intraabdominal fat,serum leptin levels,and insulin resistance induced by a high-fat diet in rats

The levels of circulating nonesterified fatty acids increase during obesity and contribute to insulin resistance by inhibiting insulin-stimulated glucose transport and phosphorylation in human muscles. In cells, glucose-6-phosphate is primarily used in glycogenesis and glycolysis; only 1% to 3% is converted to glucosamine-6-phosphate, which enters the hexosamine-biosynthesis pathway. The major end product of this pathway, uridine-5′-diphosphate-N-acetyl-glucosamine, which is increased by exogenous glucosamine (GlcN) administration, mediates insulin resistance. We hypothesized that the administration of GlcN to rats receiving a high-fat (HF) diet may potentiate the effects of an HF diet on glucose tolerance and other metabolic variables. To evaluate this relationship, 2 groups of rats were fed with a control or HF diet; and another 2 groups received glucosamine hydrochloride at a dose of 500 mg/kg dissolved in drinking water for 21 weeks. Metabolic variables related to insulin resistance were then measured. The levels of blood glucose and serum insulin were higher in a glucose tolerance test in the HF group as compared with the control group. Rats receiving GlcN had reduced liver glycogen and only slightly worsened glucose tolerance as compared with control rats, although this did not induce insulin resistance as evaluated by the homeostasis model assessment. Glucosamine administration was able to partially or completely inhibit some effects of the HF diet by reducing fat depot weight and serum leptin levels, thus resulting in a smaller increase in the insulinemic response to a glucose injection and lower postabsorptive glycemia.     

重复性“饥饿/再投喂”对大鼠体重控制与能量平衡调节的影响

目的探讨经过重复性"饥饿/再投喂"饲喂方式处理的大鼠再摄取高脂食物时,与体重控制和能量平衡调节有关的瘦素(leptin)和一系列神经内分泌因子及激素的表达变化。方法设计"重复性饥饿1天/再投喂1天,持续6周"的饲喂方式(基础饲料)处理实验组(RFR),实验-高脂饲料组大鼠(RFR-LF/HF)另6周改为每天喂以高脂饲料。对照组随机分为3组,对照组喂基础饲料6周后处死,高脂饲料组改用高脂饲料,基础饲料组继续用基础饲料喂养至12周。比较各组大鼠体重、Lee’s指数和脂体比的差异,检测血脂、血清生长激素、甲状腺素、瘦素、胰岛素和血浆促肾上腺皮质激素含量,应用RT-PCR法检测下丘脑神经肽Y(NPY)、前阿黑皮素原(POMC)mRNA的表达水平。结果 RFR-LF/HF组Lee’s指数、脂体比、血清总胆固醇(TC)、甘油三酯(TG)、低密度脂蛋白(LDL)、瘦素和胰岛素水平均显著低于高脂饲料组而高于基础饲料组,下丘脑NPY mRNA表达水平显著高于高脂饲料组和基础饲料组,POMC mRNA表达水平显著低于高脂饲料组和基础饲料组。结论重复性"饥饿/再投喂"饲喂处理可降低高脂饮食诱导的肥胖程度,减轻瘦素抵抗和胰岛素抵抗,但会引起中枢神经内分泌肽表达的极度紊乱。     

β3-adrenoceptor agonist prevents alterations of muscle diacylglycerol and adipose tissue phospholipids induced by a cafeteria diet

Background

Insulin resistance induced by a high fat diet has been associated with alterations in lipid content and composition in skeletal muscle and adipose tissue. Administration of β3-adrenoceptor (β3-AR) agonists was recently reported to prevent insulin resistance induced by a high fat diet, such as the cafeteria diet. The objective of the present study was to determine whether a selective β3-AR agonist (ZD7114) could prevent alterations of the lipid profile of skeletal muscle and adipose tissue lipids induced by a cafeteria diet.

Methods

Male Sprague-Dawley rats fed a cafeteria diet were treated orally with either the β3-AR agonist ZD7114 (1 mg/kg per day) or the vehicle for 60 days. Rats fed a chow diet were used as a reference group. In addition to the determination of body weight and insulin plasma level, lipid content and fatty acid composition in gastronemius and in epididymal adipose tissue were measured by gas-liquid chromatography, at the end of the study.

Results

In addition to higher body weights and plasma insulin concentrations, rats fed a cafeteria diet had greater triacylglycerol (TAG) and diacylglycerol (DAG) accumulation in skeletal muscle, contrary to animals fed a chow diet. As expected, ZD7114 treatment prevented the excessive weight gain and hyperinsulinemia induced by the cafeteria diet. Furthermore, in ZD7114 treated rats, intramyocellular DAG levels were lower and the proportion of polyunsaturated fatty acids, particularly arachidonic acid, in adipose tissue phospholipids was higher than in animals fed a cafeteria diet.

Conclusions

These results show that activation of the β3-AR was able to prevent lipid alterations in muscle and adipose tissue associated with insulin resistance induced by the cafeteria diet. These changes in intramyocellular DAG levels and adipose tissue PL composition may contribute to the improved insulin sensitivity associated with β3-AR activation.     

Polyunsaturated fatty acid-rich diets: effect on adipose tissue metabolism in rats

The aim of the present study was to evaluate the effect of diets rich in n-6 and n-3 fatty acids on adipose tissue metabolism. Starting at weaning, male Wistar rats were fed ad libitum, for 8 weeks with one of the following diets: C, rat chow; S, rat chow containing 15 % (w/w) soyabean oil; F, rat chow containing 15 % (w/w) fish oil; SF, rat chow containing 15 % (w/w) soyabean and fish oil (5:1, w/w). Casein was added to the fat diets to achieve the same 20 % (w/w) protein content as in the control chow. Food intake and body weight were measured weekly. The rats were killed by decapitation and the retroperitoneal (RET) and epididymal (EPI) white adipose tissues were removed and weighed. Tissue lipid and protein content, in vivo lipogenesis rate, uptake of diet-derived lipids, in vitro lipolytic rate, adipocyte area, lipoprotein lipase, ATP citrate lyase, and malic enzyme activities were evaluated. Carcass lipid and protein contents were also measured. Energy intake was reduced while carcass lipid content was increased in the three fat-fed groups. However, carcass protein and body weight gains were elevated only with diets F and SF. Lipolysis rate was diminished by diets F and SF, while the uptake of diet-derived lipids was elevated by the diet S in both RET and EPI tissues. These metabolic alterations may have contributed to the increase in in vivo lipogenesis rate in the presence of decreased ATP citrate lyase and malic enzyme activities induced by the three lipid diets. These results indicate that enrichment of the diet with polyunsaturated fatty acids causes changes in adipose tissue metabolism that favour fat deposition. Different metabolic pathways were preferentially affected by each type of fatty acid used.     

Bitter melon (Momordica charantia) reduces adiposity,lowers serum insulin and normalizes glucose tolerance in rats fed a high fat diet

Bitter melon (BM) is known for its hypoglycemic effect but its effect on rats fed a hyperinsulinemic high fat diet has not been examined. In a dose-response (0.375, 0.75 and 1.5%) study, oral glucose tolerance was improved in rats fed a high fat (HF; 30%) diet supplemented with freeze-dried BM juice at a dose of 0.75% or higher (P < 0.05). At the highest dose, BM-supplemented rats had lower energy efficiency (P < 0.05) and tended (P = 0.10) to have less visceral fat mass. In a subsequent experiment, rats habitually fed a HF diet either continued to consume the diet or were switched to a HF+BM, low fat (LF; 7%) or LF+BM diet for 7 wk. BM was added at 0.75%. Final body weight and visceral fat mass of the two last-mentioned groups were similar to those of rats fed a LF diet for the entire duration. Rats switched to the HF+BM diet gained less weight and had less visceral fat than those fed the HF diet (P < 0.05). The addition of BM did not change apparent fat absorption. BM supplementation to the HF diet improved insulin resistance, lowered serum insulin and leptin but raised serum free fatty acid concentration (P < 0.05). This study reveals for the first time that BM reduces adiposity in rats fed a HF diet. BM appears to have multiple influences on glucose and lipid metabolism that strongly counteract the untoward effects of a high fat diet.     

Purslane extract effects on obesity-induced diabetic rats fed a high-fat diet

Purslane extract in the form of ethanolic formulation is rich in polyphenols, flavonoids and anthocyanin, w-3 fatty acids and melatonin. The present study was designed to investigate the anti-obesity and anti-diabetic effects of purslane using obese diabetic rats. The rats received either regular diet, high-fat diet or high-fat diet with additional purslane (150 and 300 mg/kg body weight) for 8 weeks. Purslane, co-administered with a high fat diet, significantly inhibited body weight gain, blood glucose, triglyceride, total cholesterol, LDL-C, HDL-C, free fatty acids and the atherogenic index levels in a dose dependent manner. Purslane-treated rats at doses of 150 and 300 mg/kg body weight improved the insulin resistance index when compared to high fat diet control. In conclusion, purslane ethanolic extract showed effects indicative of potential anti-obesity and anti-diabetic actions in rats fed a high fat obesity-induced diet.     

Resistance to ketosis during prolonged fasting by rats fed on a diet containing undecanoic acid, an odd-carbon-number fatty acid.

1. Sixty-four male rats were fed on a nutritionally complete diet containing 30% of the dietary energy as fat. For thirty-two rats (control) the fat source was maize oil; for the remaining thirty-two rats (experimental) the fat source was triundecanoin-maize oil (7:3, w/w). 2. After 6 weeks, groups of control and experimental rats were fasted and killed on days 0, 1, 2, and 4 of the fasting period. In the experimental group, adipose-tissue fatty acids contained, on average, 246 mmol undecanoic acid/mol total fatty acids. In contrast, the adipose tissue of the control group did not contain odd-carbon-number fatty acids. 3. Plasma glucose levels were significantly higher for all fasted experimental groups and blood ketone levels were significantly lower for these groups. 4. Thus, during prolonged starvation, animals which accumulated odd-C-number fatty acids resisted the development of ketosis. It appeared that odd-C-number fatty acids mobilized from fat depots during fasting may provide their terminal three-C-residues for gluconeogenesis rather than for acetyl-CoA production, thereby allowing for better maintenance of blood glucose and insulin levels than in control animals. 5. It is concluded that the lower acetyl-CoA production and higher blood insulin levels reduce ketogenesis.     

Intake of trans fatty acid-rich hydrogenated fat during pregnancy and lactation inhibits the hypophagic effect of central insulin in the adult offspring

OBJECTIVE: Using rats we examined whether maternal intake of hydrogenated fat rich in trans fatty acids affects brain fatty acid profile, hypothalamic content of insulin receptor and insulin receptor substrate-1 proteins, and the hypophagic effect of centrally administered insulin in 3-mo-old male progeny. METHODS: Throughout pregnancy and lactation, Wistar rats ate isocaloric/normolipidic diets with soybean oil (control) or soybean oil-derived hydrogenated fat (trans diet) as a fat source. Upon weaning, the trans offspring continued on the trans diet (trans group) or were switched to a control diet (trans-control group). RESULTS: Compared with control rats, trans rats had lower brain levels of eicosapentaenoic acid. Compared with trans rats, trans-control rats had increased levels of total polyunsaturated fatty acids and arachidonic acid and decreased levels of trans fatty acids, saturated fatty acids, and monounsaturated fatty acids. Insulin receptor and insulin receptor substrate-1 levels were significantly lower (44% and 38%, respectively) in trans than in control rats. In trans-control rats, insulin receptor was 26% lower (P < 0.05), whereas insulin receptor substrate-1 was 50% lower, than in control rats. Insulin decreased 24-h feeding in control (27%) and trans (38%) rats but failed to do so in trans-control rats. The latter group had increased serum glucose levels. CONCLUSIONS: The data suggest that the early (intrauterine/perinatal) exposure to hydrogenated fat rich in trans fatty acids programmed the hypothalamic feeding control mechanisms. As young adults, only trans-control animals showed loss of insulin-induced hypophagia, indicating that the mismatch between early and later nutritional environments was relevant. However, the trans group also showed signs of altered appetite signaling mechanisms, suggesting that the early adaptations may have deleterious consequences later in life.     

Detrimental effects of a high fat diet in early renal injury are ameliorated by fish oil in Han:SPRD-cy rats

Dietary fish oils containing (n-3) fatty acids can modulate renal inflammatory injury. We previously demonstrated that a high fat (HF) diet worsens early renal disease progression in the Han:SPRD-cy rat model of polycystic kidney disease (PKD). Therefore, using HF (20 g/100 g diet) and low fat (LF; 5 g/100 g diet) diets, we compared the effects of menhaden oil (MO), soybean oil (SO) and cottonseed oil (CO) on renal function and histology in male Han:SPRD-cy rats fed the diets for 6 wk in the early stages of renal disease. Overall, rats fed HF compared with those fed LF diets had larger kidneys, more renal fibrosis and lower creatinine clearance (main effects of fat level).Rats fed MO rather than CO and SO diets had significantly lower kidney weights, kidney water content, cyst volumes and serum cholesterol and triglyceride concentrations (main effects of fat type). Rats fed MO diets also had less renal fibrosis than those fed CO diets, but the least fibrosis was in rats fed SO diets. Analysis of simple effects (due to interactions between fat level and type) revealed that HF diets increased renal inflammation in rats fed CO diets, but reduced inflammation was present in those fed SO and MO diets; HF diets also increased compared with LF diets serum urea nitrogen concentrations in rats fed the MO and CO diets, but not the SO diet. These results confirm that high dietary fat worsens early disease progression in this model of renal disease, and further demonstrate that diets with oils containing (n-3) fatty acids ameliorate some of the detrimental effects of a high fat diet.     

Effect of palatable hyperlipidic diet on lipid metabolism of sedentary and exercised rats

OBJECTIVE: The present study was designed to examine 1) whether continuous feeding with a palatable hyperlipidic diet and cycling this diet with chow diet would affect lipid and carbohydrate metabolism in a similar way; and 2) whether the effect of chronic exercise on lipid and carbohydrate metabolism would be modified by these diet regimens. METHODS: Male 25-d-old Wistar rats were assigned to one of six groups: sedentary rats fed with chow diet; exercised (swimming 90 min/d, 5 d/wk) rats fed with chow diet; sedentary rats fed with a palatable hyperlipidic diet; exercised rats fed with the palatable hyperlipidic diet; sedentary rats fed with food cycles (four cycles alternating the chow and hyperlipidic diets weekly); and exercised rats fed with food cycles. After 8 wk of treatment, the animals were killed 24 h after the last exercise session. RESULTS: The hyperlipidic diet and food cycles schedules caused similar increases in body weight gain, carcass lipogenesis rate and adiposity, lipid content of the liver and gastrocnemius muscle, and serum total lipid, triacylglycerol, insulin, and leptin levels. The exercise attenuated body weight gain, adipose tissue mass, and serum triacylglycerol, insulin, and leptin levels similarly in the hyperlipidic and food cycles groups. Carcass lipogenesis rate was not affected by exercise in any of the three groups. CONCLUSIONS: The data showed that the continuous intake of a hyperlipidic palatable diet for 8 wk and the alternation of the high-fat intake with periods of chow intake cause obesity and affected lipid metabolism in a similar way. Chronic exercise attenuated body weight gain and adiposity and improved serum lipid concentrations in both high-fat feeding regimens.     

合成油的营养评价 (一)合成油饲料对正常大鼠的生长、血脂水平、肝脂与体脂脂肪酸组成的影响

本文研究了由石油副产品尿素蜡中提炼出辛酸(8:0)和癸酸(10:0),酯化后作为日常食用油的可能性。 (1)用含12％不同油酯(合成油,豆汕,不同比例配合的合成油与豆油,和奇数碳脂肪酸的合成油等)的饲料,分别饲养断乳大鼠12周,每组16只大鼠,雌雄各半,观察其生长、脏体比、血脂与肝脂水平、肝脂与体脂的脂肪酸组成、和体脂碘价的改变。 (2)用12％合成油饲料喂养大鼠的12周内,动物生长良好,未见必需脂肪酸缺乏的典型症状。在饲养期的前8周内,各组动物的体重增长近似,在后4周内,凡掺有含偶数碳脂肪酸的合成油饲料组动物,其体重增加值皆显著较少。 (3)合成油饲料和豆油饲料比较,对大鼠血清胆固醇水平无影响,但显著使血清甘油三酯含量增高。 (4)合成油饲料不影响动物的体成分(水份、蛋白质、脂肪),其体脂含量较豆油饲料组的略低(0.05相似文献   

The effect of a high fat diet on the carnitine content of skeletal and cardiac muscle from streptozotocin-diabetic and control rats

Streptozotocin-diabetic (SZ) and control rats were maintained on high fat (HF) or on low fat (LF) diets for a period of two weeks. Skeletal and cardiac muscle were assayed for free fatty acids and for free, short-chain, and long-chain carnitine. The free fatty acid content of both skeletal and cardiac muscle was increased in SZ rats fed the LF diet and was not augmented appreciably by HF feeding. The level of free carnitine was decreased in muscles from diabetic animals maintained on the LF regimen and was unaffected by the HF diet. The amount of long-chain carnitine esters was increased in both skeletal and cardiac muscle from LF-fed SZ rats and decreased in heart from HF-fed diabetic animals. The absolute amounts of free and long-chain carnitine measured in tissue from the LF fed control rats did not differ consistently from those in muscles from HF-fed control rats. However, the long-chain carnitine/free carnitine ratio was elevated significantly in both skeletal and cardiac muscle from the HF-fed control animals, but was not increased in SZ rats maintained on the HF regimen. Together, these data suggest that high fat feeding results in increased lipid utilization in control but not in diabetic rats.     

Carcass deposition of dietary long-chain odd carbon fatty acids by rats and their effect on plasma glucose and ketone bodies during starvation.

Weanling rats were fed diets containing various levels (0 to 40% of total dietary acids) of long chain, odd-carbon fatty acids (OCFA, 15:0 + 17:0) for 5 weeks. The OCFA did not significantly alter growth or feed efficiency and the OCFA were deposited in the carcass fat in proportion to their concentration in the diet fat. After the 5-week ingestion period, the rats were starved for 48 hours and the effect of carcass OCFA content on weight loss, fat loss, urinary total nitrogen, plasma glucose concentration and plasma ketone body concentrations was determined as a function of starvation time. The results demonstrate that OCFA catabolism during starvation results in a dose related increase in plasma glucose and dose related decrease in plasma ketone bodies without significantly altering the total weight loss, carcass fat loss, or urinary total nitrogen. Finally, the carcass percentage of OCFA did not change during starvation showing that these acids are as readily lost from the carcass during starvation as even chain fatty acids.