能量平衡状态下不同膳食脂肪摄入量对大鼠血脂、体脂、脂联素及瘦素的影响

目的探讨能量平衡状态下,不同膳食脂肪摄入量对大鼠血糖、血脂、体脂、胰岛素及瘦素的影响。方法 40只SD雄性大鼠随机分为4组,分别饲喂等能量低脂饲料(脂肪供能比5%)、普通饲料(脂肪供能比15%)、中脂饲料(脂肪供能比25%)和高脂饲料(脂肪供能比40%)。测量第0、5和10周血糖和血脂水平及第0、10周血清脂联素和瘦素水平。10周末取肾周及睾周脂肪垫,计算体脂比,用realtime PCR方法测算脂肪中脂联素及瘦素mRNA的相对表达水平。结果喂养5周及10周后,中脂组和高脂组大鼠血清中甘油三酯含量显著低于低脂组和普通组;10周末,中脂组脂肪中脂联素mRNA的表达水平显著低于低脂组;体脂比、血糖、血胆固醇、血清脂联素和瘦素水平以及脂肪中瘦素mRNA的相对表达水平,各组间均无显著性差异。结论能量平衡状态下,不同的膳食脂肪摄入量对大鼠体脂、血糖、血清甘油三酯、脂联素及瘦素水平均无影响。     

邻苯二甲酸二(2-乙基己基)酯、氯氰菊酯单独及联合染毒对青春前期雄性大鼠生殖发育的不良影响

目的探讨邻苯二甲酸二(2-乙基己基)酯(DEHP)和氯氰菊酯(CYP)单独及联合染毒对青春前期雄性大鼠生殖发育的不良影响。方法选择SPF级3周龄雄性SD大鼠24只,随机分为4组,分别为对照组(喂饲玉米油)、DEHP染毒组(500mg/kg)、CYP染毒组(80mg/kg);DEHP、CYP联合染毒组(DEHP 500mg/kg+CYP 80mg/kg),每组6只。采用经口灌胃方式染毒,每天1次,连续染毒30天。于末次染毒24小时后处死动物,测定大鼠体重、睾丸湿重,并计算睾丸系数;测定血清睾酮水平;制备睾丸病理组织切片,光镜观察其组织学改变,电镜观察生殖细胞超微结构;测定睾丸标志酶乳酸脱氢酶(LDH)、酸性磷酸酶(ACP)、碱性磷酸酶(ALP)和琥珀酸脱氢酶(SDH)的活性。结果与对照组相比,DEHP、CYP单独及联合染毒组睾丸下降时间和包皮分离时间明显延迟,肛门生殖器间距明显缩短(P<0.05或0.01);DEHP单独染毒组睾丸重量及睾丸系数明显降低,血清睾酮水平显著下降(P<0.05),睾丸匀浆中ALP、ACP和LDH活性明显增高,SDH活性显著下降(P<0.01);DEHP、CYP单独及联合染毒组睾丸病理组织学、生殖细胞超微结构均可见明显异常。结论 DEHP、CYP单独及联合染毒对青春前期雄性大鼠均具有明显的生殖毒性作用,可引起生精细胞、支持细胞和间质细胞的变性、坏死及功能障碍,从而导致雄性生殖系统发育和功能的显著异常。其中,DEHP单独染毒呈现主效应,DEHP、CYP联合染毒对大鼠的生殖毒性未呈现明显交互影响。     

妊娠期二月桂酸二丁基锡暴露对子代雄性大鼠生殖系统的影响

目的探讨妊娠期二月桂酸二丁基锡(DBTD)暴露对子代雄性大鼠性成熟后生殖系统的影响及其作用机制。方法将16只健康SPF级妊娠Wistar大鼠随机分为4组,分别为溶剂对照(玉米油)组和低(10 mg/kg)、中(20 mg/kg)、高剂量(30 mg/kg)DBTD染毒组,每组4只。采用灌胃方式进行染毒,染毒容量为5 ml/kg,自妊娠第12～20天连续染毒。仔鼠出生后第70天,每组随机抽取10只雄性大鼠,称重后处死,测定睾丸和附睾重量及其脏器系数、附睾精子数以及血清中黄体生成素(LH)、卵泡刺激素(FSH)和睾酮(T)以及睾丸组织中睾酮(T)的水平,并观察睾丸组织病理学改变。结果各剂量DBTD染毒组子代雄性大鼠体重、附睾重量及其脏器系数、血清中LH和FSH水平与溶剂对照组相比,差异均无统计学意义。与溶剂对照组比较,高剂量DBTD染毒组子代雄性大鼠睾丸重量及其脏器系数,中、高剂量DBTD染毒组子代雄性大鼠附睾精子数较高,差异均有统计学意义(P0.05或P0.01)。且随着DBTD染毒剂量的升高,子代雄性大鼠睾丸重量及其脏器系数以及附睾精子数均呈升高趋势。与溶剂对照组比较,高剂量DBTD染毒组子代雄性大鼠血清T水平和各剂量DBTD染毒组子代雄性大鼠睾丸T水平均较高,差异有统计学意义(P0.05或P0.01)。结论在本实验染毒时间和剂量范围内,孕期DBTD染毒可干扰子代雄性大鼠体内T的合成和代谢,从而促进睾丸发育和精子形成。     

烟草烟雾对青春期雄性大鼠性激素水平的影响

目的探讨烟草烟雾对青春期雄性大鼠睾丸损伤及性激素的影响。方法将5周龄SPF级雄性SD大鼠80只随机分为对照组和染毒组,每组40只。染毒组采用呼吸道静式染毒法吸入烟草烟雾,每日1次,每次2 h,共染毒8周。于染毒后第2、4、6、8周分别处死染毒组与对照组大鼠各10只,观察大鼠睾丸组织结构,并测定血清中睾酮(T)、卵泡刺激素(FSH)、黄体生成素(LH)水平。结果染毒6、8周时大鼠睾丸重量低于对照组,染毒4~8周时大鼠血清中T、LH水平低于对照组,染毒2~8周时FSH水平低于对照组,差异均有统计学意义(P0.05)。睾丸病理切片显示,染毒组大鼠睾丸组织萎缩、细胞裂解、间质组织变性。结论烟草烟雾可导致青春期雄性大鼠睾丸组织损伤,血清性激素水平降低。     

乐果对雄性大鼠生殖系统及其胎鼠发育的影响

目的：为进一步观察长期摄入小剂量乐果对雄性大鼠生殖系统及其胎鼠发育的影响。方法：以12.50mg/Kg浓度的乐果灌胃断乳SD大鼠60只。结果：发现其血清睾酮（To)和间质细胞刺激素（LH）浓度明显降低（P＜0．001和P＜0．05）；睾丸碱酸性磷酸酶（ACP），乳酸脱氢酶（LDH）的活性明显抑制（P＜0．05）；睾丸部分曲精小管上皮层次有所减少，多为2层；上皮部分有变性；部分腔内成熟精子减少；胎鼠体重明显减小，并有短肢畸形和吸收胎。结论：长期摄入小剂量乐果对大鼠雄性生殖系统及其胎鼠发育有一定程度的危害。     

呋喃丹对大鼠睾丸组织标志酶活性影响的动态观察

为探讨农药呋喃丹对雄性大鼠睾丸组织的损害作用 ,以低、中、高剂量 (0 3、1 5和 3 0mg kgBW)经口连续染毒 77天 ,分别于染毒第 7、35和 77天检测大鼠血清及睾丸组织匀浆中 β-葡萄糖苷酶 (β-G)、葡萄糖 - 6 -磷酸脱氢酶 (G - 6 -PD)、乳酸脱氢酶同工酶X(LDHx、)的活性。结果显示 ,染毒第 7天大鼠 3个染毒组血清中 β -G活性显著低于对照组 (P <0 0 5) ,低剂量组睾丸组织匀浆中 β -G活性高于对照组、而高剂量组低于对照组 (P <0 0 5) ;染毒第 77天中高剂量组血清中G - 6 -PD活性 ,高剂量组睾丸组织匀浆中LDHx活性均低于对照组 (P <0 0 5) ,其它指标及时段未见明显改变。提示呋喃丹对大鼠睾丸组织有一定损害作用。     

橄榄油和鱼油对大鼠血脂和脂质过氧化的影响

为观察橄榄油和鱼油对大鼠血脂水平及脂质过氧化的影响 ,将 44只Wistar大鼠随机分成 4组 ,分别接受正常饲料、高脂饲料、高脂饲料加橄榄油灌胃 (4ml·kg- 1 ·d- 1 )和高脂饲料加鱼油灌胃 (4ml·kg- 1 ·d- 1 )处理。实验期 6周。结果显示 ,橄榄油和鱼油均能降低大鼠血清总胆固醇和甘油三酯水平 ,并且鱼油的效果较橄榄油好 ,鱼油能够显著提高高密度脂蛋白胆固醇 ;橄榄油和鱼油均可降低高脂饲料引起的肝 体比值增大 ,而且鱼油可以明显减少肾脏和睾丸周围脂肪。橄榄油组和鱼油组大鼠的血清丙二醛水平均明显下降 ;而且红细胞超氧化物歧化酶活性有所提高 ,表明橄榄油和鱼油对进食高脂饲料引起的体内过氧化物水平升高具有拮抗作用。结果提示橄榄油和鱼油对高血胆固醇、甘油三酯有降低作用 ,并能改善高脂所致体内过氧化状态异常 ,减轻对机体的过氧化损伤 ,鱼油的效果优于橄榄油     

长期低剂量双酚A暴露对高脂喂养大鼠肝脏的影响

目的探讨长期低剂量双酚A(BPA)暴露对雄性大鼠肝脏的影响。方法将50只8周龄雄性Wistar大鼠随机分为普通对照组、高脂对照组、高脂饲料+低剂量BPA[10μg/(kg·d)]组、高脂饲料+中剂量BPA[50μg/(kg·d)]组和高脂饲料+高剂量BPA[250μg/(kg·d)]组,共5组。连续35周通过饮食途径给予大鼠BPA后,测定体质量、肝脏系数、体脂百分数,肝脏中甘油三酯、总胆固醇、丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)以及肝脏丙二醛(MDA)和谷胱甘肽过氧化物酶(GSH-Px)指标。结果高脂饲料组与普通饲料组血清中AST水平无差别,但高脂饲料组的血清中ALT水平明显高于普通饲料组(P0.01);此外,高脂饮食+高剂量BPA组大鼠血清中AST和ALT水平均明显高于高脂饲料组(P0.05),不同剂量的BPA对大鼠体质量、体脂百分数、肝脏中脂肪及MDA和GSH-Px均无明显影响(P0.05)。结论长期高剂量BPA暴露对高脂喂养雄性大鼠肝脏功能具有明显的损害作用。     

等能量摄食条件下不同膳食脂肪供能比对大鼠血糖、血脂的影响

目的探讨等能量摄食条件下不同膳食脂肪供能比对大鼠血糖和血脂等指标的影响。方法将40只雄性SD大鼠按随机区组法分为低脂饲料、普通饲料、中脂饲料和高脂饲料组4组,等能量饲喂脂肪供能比分别为5%、15%、25%、40%的饲料10周。每周测大鼠体重和体长,第0、5和10周取尾血测空腹血糖、血脂和胰岛素水平,第10周末取肾周及附睾周脂肪称重,计算体脂比。结果实验第5、10周,大鼠体重、Lee's指数、体脂比、血清胰岛素和低密度脂蛋白胆固醇水平在各组间差异无统计学意义;第10周,高脂组血糖与低脂组相比显著升高(P0.01);高脂组总胆固醇、甘油三酯、高密度脂蛋白胆固醇与低脂组相比显著降低(P0.01);第10周,高脂组血糖与0周相比升高(P0.05),高脂组总胆固醇、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇与0周相比降低(P0.01)。结论在等能量摄食、正常生长条件下,高脂肪供能比饲料不会引起大鼠肥胖,但可能会导致大鼠糖脂水平的改变。     

十溴联苯醚对雄性大鼠生殖系统的影响

将60只SD雄性大鼠随机分为空白对照组、溶剂对照组及BDE-209低、中、高(250 mg/kg,500 mg/kg,1 000 mg/kg)剂量组,每天灌胃1次,持续30 d;显微镜下观察并计算大鼠精子的数量、活动度和畸形率;应用放射免疫法测定雄性大鼠血清中睾酮(testosterone,T)、黄体生成素(luteinizing hormone,LH)、卵泡刺激素(follicle stimula-ting hormone,FSH)的水平。与对照组比较,BDE-209染毒组大鼠睾丸和附睾脏器系数明显下降,大鼠睾丸和附睾脏器系数与染毒剂量存在效应关系(P<0.05)。BDE-209染毒组大鼠精子数量和精子活动度明显低于对照组,精子畸形率明显高于对照组,大鼠精子的数量、活动度和畸形率与染毒剂量存在效应关系(P<0.05)。BDE-209染毒组大鼠血清中T、LH和FSH水平明显低于对照组,且呈剂量-效应关系。提示BDE-209亚急性染毒对雄性成年大鼠具有一定的生殖毒性。     

Better dietary adherence and weight maintenance achieved by a long-term moderate-fat diet

The objective of the present study was to determine the effects of a long-term moderate-fat diet (30 % energy from fat) v. a low-fat one (20 % energy from fat) on metabolic risks. The study was a randomised, prospective 14-month trial on overweight and obese patients (eighty-nine overweight and obese men and women). The intervention was a moderate-fat diet (30 % energy) or a low-fat diet (20 % energy). The main outcome measurements were change in body weight, waist circumference, LDL-cholesterol, HDL-cholesterol, total cholesterol, TAG, and systolic and diastolic blood pressure. Forty-five subjects on the moderate-fat diet and forty-four subjects on the low-fat one were studied. Characteristics of all randomised participants were similar in both groups. After 7 months, the moderate- and low-fat diets had similar effects on cardiovascular risks. The moderate-fat diet was more successful after 14 months in reducing weight ( -5.0 (SD 2.5) kg in the moderate-fat group v. -1.2 (SD 1.1) kg in the low-fat one; P < 0.0001), waist circumference (-5.5 (SD 2.4) cm in the moderate-fat group v. - 2.3 (SD 1.3) cm in the low-fat one; P < 0.0001), and other cardiovascular risk factors as well (LDL, TAG, total cholesterol and systolic blood pressure). In conclusion, a moderate-fat energy-restricted diet in the long term might have more beneficial effects on weight maintenance and cardiovascular risk factors compared with a low-fat diet. Better dietary adherence with the moderate-fat diet may be the reason for its successful effects.     

Effects of high-fat diet intake on glucose uptake in central and peripheral tissues of non-obese rats

We previously demonstrated that plasma glucose concentration was higher while plasma insulin concentration was lower in rats fed a high-fat diet. In the present study, we examined the effects of high-fat diet on glucose uptake in central and peripheral tissues in non-obese rats. Forty male Sprague-Dawley rats were fed high- or low-fat diets for 4 wk. Body weight and body fat accumulation were not different between the two diet groups after 4 wk. Glucose uptake in the skeletal muscles and adipose tissues, estimated by the 2-deoxy-D-glucose method, was lower in the rats fed the high-fat diet than that in the rats fed the low-fat diet, whereas uptake in the liver and pancreas did not differ between the two groups. Glucose uptake in the hypothalamus and cortex was higher in the high-fat diet group as compared with that in the low-fat diet group. These results suggest that increased plasma glucose levels in rats fed the high-fat diet were caused by a decrease in glucose uptake in the skeletal muscles and adipose tissues. Reduced plasma insulin level in the high fat diet group with no difference in glucose uptake in the pancreas may be due to increased sympathetic activity in the pancreas resulting from the increased glucose uptake in the brain regions involved in autonomic functions.     

Modulation of body fat and serum leptin levels by dietary conjugated linoleic acid in Sprague-Dawley rats fed various fat-level diets

OBJECTIVES: In this study, we examined the effect of dietary conjugated linoleic acid (CLA) on body fat levels in Sprague-Dawley rats. METHODS: Rats were fed AIN-93G type diets containing 4%, 7%, and 10% fats with or without 1.5% CLA. RESULTS: Three weeks after the onset of the experimental period, the weights of perirenal white adipose tissue were lower in CLA-fed rats. The weights of epididymal white adipose tissue also were lower in CLA-fed rats than in control rats, but this effect disappeared with increased dietary fat level. Serum leptin levels tended to be lower in the CLA group, especially the low-fat diet group, than in the control group. There were significant positive correlations between serum leptin level and weights of perirenal and epididymal white adipose tissues in control groups, but these correlations were weaker in the CLA groups. Serum tumor necrosis factor-alpha levels also tended to be lower in CLA-fed rats, and this tendency was most remarkable in the rats fed 7% fat diets. CONCLUSION: In conclusion, dietary CLA, especially the low-fat diet, reduced body fat without hepatic injury to Sprague-Dawley rats.     

Characteristics of nonalcoholic fatty liver disease induced in wistar rats following four different diets

BACKGROUND/OBJECTIVESThe prevalence of nonalcoholic fatty liver disease (NAFLD) has increased worldwide in parallel with overnutrition characterized by high-fat and high-carbohydrate intake. Our objective was to establish, in 16 weeks, a model of NAFLD in Wistar pathogen-free rats following four dietary types.MATERIALS/METHODSForty (6 weeks old) healthy Wistar male rats, weighing an average of 150 g were randomly divided into four groups of ten and assigned a diet with the same quantity (15 g/rat/day), but with different composition. The moderate-fat (MF) group was fed a moderate-fat diet (31.5% fat and 50% carbohydrates), the high-fat (HF) group was fed a fat-rich diet (51% fat), the high-sucrose (HS) group and the high-fructose (HFr) group were fed a carbohydrate-rich diet (61%). The carbohydrate contents of the HS group was composed of 60.3% sucrose while that of the HFr group was composed of 59.3% fructose.RESULTSAt week 16, the HF group had the highest percentage of cells enriched in fat (40%) and the highest weight and liver weight (P < 0.05). The HFr group showed significantly higher levels of serum triglycerides, alanine aminotransferase and adiponectin at week 16 as compared to week 1 (P < 0.05).CONCLUSIONSThe 15 g/rat/day diet composed of 51% fat or 61% carbohydrates enriched mainly in fructose may induce characteristics of NAFLD in rats.     

长期应激结合高脂饲料对大鼠胸主动脉的损伤作用

[目的]观察长期应激结合高脂饲料对大鼠胸主动脉的损伤作用。[方法]雄性Wistar大鼠24只,随机分为4组,每组6只,分别为对照组（c组）、高脂饲料喂养组（HC组）、单纯足底电刺激并辅以噪声刺激组（CS组）及高脂饲料结合应激组（HC＋CS组）。持续12周实验结束后取血,取胸主动脉。检测大鼠血清中总胆固醇（TC）、三酰甘油（TG）、高密度脂蛋白（HDL）、低密度脂蛋白（LDL）、游离脂肪酸（FFA）、超氧化物歧化酶（SOD）、丙二醛（MDA）、超氧阴离子（O^-2）;采用放免法检测血清中肿瘤坏死因子（TNF-α）、ELISA法检测氧化型低密度脂蛋白（OX-LDL）,电镜观察胸主动脉病理变化。[结果]血清学指标检测显示HC＋CS组与HC组及cs组有明显的区别：出现了更明显的血脂紊乱（TC、FFA、LDL升高,HDL下降,尤其OX-LDL升高很明显）,炎症反应（血清TNF-α升高）,氧化应激（SOD活力明显下降,血清MDA和O^-2水平明显升高）;同时电镜观察发现HC＋CS组的胸主动脉也出现了明显损伤,而HC组和cs组的损伤程度明显较轻。[结论]长期应激结合高脂饲料有协同作用,可促进大鼠胸主动脉的损伤。     

Effects of moderate-fat (from monounsaturated fat) and low-fat weight-loss diets on the serum lipid profile in overweight and obese men and women

BACKGROUND: Little evidence of the effects of moderate-fat (from monounsaturated fat) weight-loss diets on risk factors for cardiovascular disease exists because low-fat diets are typically recommended. Previous studies in weight-stable persons showed that a moderate-fat diet results in a more favorable lipid and lipoprotein profile (ie, lower serum triacylglycerol and higher HDL cholesterol) than does a low-fat diet. OBJECTIVE: We evaluated the effects of energy-controlled, low-fat and moderate-fat diets on changes in lipids and lipoproteins during weight loss and subsequent weight maintenance. DESIGN: We conducted a parallel-arm study design in overweight and obese [body mass index (in kg/m(2)): 29.8 +/- 2.4] healthy men and women (n = 53) assigned to consume a low-fat (18% of energy) or moderate-fat (33% of energy) diet for 6 wk to achieve weight loss, which was followed by 4 wk of weight maintenance. All foods were provided and body weight was monitored to ensure equal weight loss between groups. RESULTS: The moderate-fat diet elicited favorable changes in the lipoprotein profile. Compared with baseline, HDL cholesterol was unchanged, whereas triacylglycerol and the ratios of total and non-HDL cholesterol to HDL cholesterol were lower at the end of the weight-maintenance period in the moderate-fat diet group. Despite similar weight loss, triacylglycerol rebounded, HDL cholesterol decreased, and the ratios of total and non-HDL cholesterol to HDL cholesterol did not change during the 10-wk interval in the low-fat diet group. CONCLUSIONS: A moderate-fat weight-loss and weight-maintenance diet improves the cardiovascular disease risk profile on the basis of favorable changes in lipids and lipoproteins. There is merit in recommending a moderate-fat weight-loss diet.     

Grape skin improves antioxidant capacity in rats fed a high fat diet

This study was conducted to investigate the effect of dietary grape skin on lipid peroxidation and antioxidant defense system in rats fed high fat diet. The Sprague-Dawley rats were fed either control (5% fat) diet or high fat (25% fat) diet which was based on AIN-93 diet for 2 weeks, and then they were grouped as control group (C), control + 5% grape skin group (CS), high-fat group (HF), high fat + 5% grape skin group (HFS) with 10 rats each and fed corresponding diets for 4 weeks. The hepatic thiobarbituric acid reacting substances (TBARS) were increased in high fat group as compared with control group, but reduced by grape skin. The serum total antioxidant status, and activities of hepatic catalase and superoxide dismutase, xanthine oxidase and glucose-6-phosphatase were increased by supplementation of grape skin. Glutathione peroxidase activity was significantly higher in CS group than in C group. Grape skin feeding tended to increase the concentration of total glutathione, especially in control group. The ratio of reduced glutathione to oxidized glutathione was lower in high fat groups than in control groups. The ratio was increased by dietary supplementation of grape skin in control group. These results suggest that dietary supplementation of grape skin would be effective on protection of oxidative damage by lipid peroxidation through improvement of antioxidant defense system in rats fed high fat diet as well as rats with low fat diet.     

Lactation decreases pancreatic lipase mRNA level in the rat

Lactation alters maternal metabolism and increases food intake in rats to support milk production. Pancreatic lipase (PL) is primarily responsible for fat digestion in adults and is regulated by dietary fat. The present research determined the regulation of PL by lactation and dietary fat. In Expt 1, eighteen Sprague-Dawley dams and twelve age-matched virgins (controls) were fed a low-fat diet (LF; 11 % energy as safflower oil) for 7-63 d. At postpartum (day 0), peak lactation (day 15) and post-lactation (day 56) and after 7 d in virgins, the pancreas was removed for mRNA and enzyme analyses. In Expt 2, thirty-six Sprague-Dawley dams were fed LF until day 9 postpartum when dams were divided into three groups of twelve; one continued to be fed LF, one was fed a moderate-fat diet (MF; 40 % energy as safflower oil); and one was fed a high-fat diet (HF; 67 % energy as safflower oil) diet. At peak lactation (day 15) and post-lactation (day 56), the pancreas was removed for mRNA and enzyme analyses. Expt 1 revealed that lactation and post-lactation significantly (P<0.001) decreased PL mRNA (67 % and 76 %, respectively), but only post-lactation decreased PL activity. Increased dietary fat in Expt 2 significantly increased PL mRNA (LF相似文献   

High dietary fat intake increases renal cyst disease progression in Han:SPRD-cy rats

The effect of a high level of dietary fat on renal cyst disease was examined in the Han:SPRD-cy rat model of polycystic kidney disease. Control and diseased rats at 4 wk of age were fed either a low fat or high fat diet (5 or 20 g/100 g diet) for 6 wk. In rats with kidney disease fed the high fat rather than the low fat diet, kidneys were 17% larger, renal fluid content was 19% higher and cyst scores were 30% higher, indicating greater disease progression. In diseased rats fed the high fat diet, serum urea was 25% higher, indicating worsened renal function. Serum creatinine was 49% higher only in males. To examine whether high dietary fat worsened renal cyst disease by altering sex hormone concentrations, serum testosterone and estrogen concentrations were determined. In normal compared with diseased male rats, serum testosterone concentrations were one to three times higher. Serum testosterone concentrations were higher in normal male rats fed the high compared with the low fat diet, but were not affected by diet in diseased rats. Serum estrogen concentrations were unaffected by dietary fat levels or by disease state. Although it remains to be elucidated how dietary fat influences sex hormone concentrations in this disease, the current study demonstrates that a high dietary fat intake increases kidney disease progression in Han:SPRD-cy rats.     

Dietary n-3 fatty acids affect mRNA level of brown adipose tissue uncoupling protein 1, and white adipose tissue leptin and glucose transporter 4 in the rat

We examined the effect of dietary fats rich in n-3 polyunsaturated fatty acids (PUFA) on mRNA levels in white and brown adipose tissues in rats. Four groups of rats were fed on a low-fat diet (20 g safflower oil/kg) or a high-fat diet (200 g/kg) containing safflower oil, which is rich in n-6 PUFA (linoleic acid), or perilla (alpha-linolenic acid) or fish oil (eicosapentaenoic and docosahexaenoic acids), both of which are rich in n-3 PUFA, for 21 d. Energy intake was higher in rats fed on a high-safflower-oil diet than in those fed on low-fat or high-fish-oil diet, but no other significant differences were detected among the groups. Perirenal white adipose tissue weight was higher and epididymal white adipose tissue weight tended to be higher in rats fed on a high-safflower-oil diet than in those fed on a low-fat diet. However, high-fat diets rich in n-3 PUFA, compared to a low-fat diet, did not increase the white adipose tissue mass. High-fat diets relative to a low-fat diet increased brown adipose tissue uncoupling protein 1 mRNA level. The increases were greater with fats rich in n-3 PUFA than with n-6 PUFA. A high-safflower-oil diet, compared to a low-fat diet, doubled the leptin mRNA level in white adipose tissue. However, high-fat diets rich in n-3 PUFA failed to increase it. Compared to a low-fat diet, high-fat diets down-regulated the glucose transporter 4 mRNA level in white adipose tissue. However, the decreases were attenuated with high-fat diets rich in n-3 PUFA. It is suggested that the alterations in gene expression in adipose tissue contribute to the physiological activities of n-3 PUFA in preventing body fat accumulation and in regulating glucose metabolism in rats.