Blood ammonia concentration in mice: normal reference values and changes during growth

To establish normal reference values of blood ammonia concentration in mice, possible factors which may affect blood ammonia determination such as age, sex, strain and sampling site of blood, were investigated by the microdiffusion method. The ammonia concentration in blood collected from the tail (mixture of venous and arterial blood) and left ventricle was significantly higher than that in venous blood collected from the orbital sinus and right auricle. Neither strain nor sex differences were observed. Blood ammonia concentration in newborn pups was 92 +/- 19 micrograms/dl immediately after birth and increased to 184 +/- 22 micrograms/dl 24 hours after birth. This increased level was maintained for a week. By 15 days, it decreased to the level at birth. Thereafter, no significant variation with age was observed. Blood ammonia concentration in mice after weaning, irrespective of age, sex and strain, varied from 38 to 123 micrograms/dl, with a mean +/- SD of 79 +/- 18 micrograms/dl.     

Whey Protein Reduces Early Life Weight Gain in Mice Fed a High-Fat Diet

An increasing number of studies indicate that dairy products, including whey protein, alleviate several disorders of the metabolic syndrome. Here, we investigated the effects of whey protein isolate (whey) in mice fed a high-fat diet hypothesising that the metabolic effects of whey would be associated with changes in the gut microbiota composition. Five-week-old male C57BL/6 mice were fed a high-fat diet ad libitum for 14 weeks with the protein source being either whey or casein. Faeces were collected at week 0, 7, and 13 and the fecal microbiota was analysed by denaturing gradient gel electrophoresis analyses of PCR-derived 16S rRNA gene (V3-region) amplicons. At the end of the study, plasma samples were collected and assayed for glucose, insulin and lipids. Whey significantly reduced body weight gain during the first four weeks of the study compared with casein (P<0.001–0.05). Hereafter weight gain was similar resulting in a 15% lower final body weight in the whey group relative to casein (34.0±1.0 g vs. 40.2±1.3 g, P<0.001). Food intake was unaffected by protein source throughout the study period. Fasting insulin was lower in the whey group (P<0.01) and glucose clearance was improved after an oral glucose challenge (P<0.05). Plasma cholesterol was lowered by whey compared to casein (P<0.001). The composition of the fecal microbiota differed between high- and low-fat groups at 13 weeks (P<0.05) whereas no difference was seen between whey and casein. In conclusion, whey initially reduced weight gain in young C57BL/6 mice fed a high-fat diet compared to casein. Although the effect on weight gain ceased, whey alleviated glucose intolerance, improved insulin sensitivity and reduced plasma cholesterol. These findings could not be explained by changes in food intake or gut microbiota composition. Further studies are needed to clarify the mechanisms behind the metabolic effects of whey.     

Influence of high-fat diet on host animal health via bile acid metabolism and benefits of oral-fed Streptococcus thermophilus MN-ZLW-002

In this study, C57BL/6J male mice were fed normal chow (NC; control) or a high-fat diet (HFD) for 12 weeks, and HFD mice were supplemented with oral administration of Streptococcus thermophilus MN-ZLW-002 (HFD + MN002); n=20/group. Body weight, visceral fat, blood glucose, blood lipids and liver lipid deposition increased in the HFD group, and the composition of gut microbiota, cecum short-chain fatty acids and fecal bile acids (BAs) also changed. Oral-fed MN-002 increased the relative abundances of Ruminococcaceae, Lachnospiraceae and Streptococcaceae and improved blood glucose, liver cholesterol deposition, and serum IL-10, CCL-3 and the fecal BAs composition. In conclusion, the high-fat diet changed the composition of bile acids by shaping the gut microbiota into an obese type, leading to metabolic disturbances. Streptococcus thermophilus MN-ZLW-002 regulated gut microbiota by adjusting the composition of bile acids and improved the perturbation caused by high-fat diets. However, the effect of MN002 observed in animal experiments needs to be verified by long-term clinical trials.     

Generation and characterization of a mouse model of the metabolic syndrome: apolipoprotein E and aromatase double knockout mice

The aim of this study was to create a comprehensive mouse model of the metabolic syndrome by crossing aromatase-deficient (ArKO) mice with apolipoprotein E-deficient (ApoE(-/-)) mice. Successive crossbreeding of ArKO with ApoE(-/-)-deficient mice generated double knockout, MetS-Tg mice. The phenotypic characteristics of the MetS-Tg mice were assessed at 3, 6, and 12 mo of age and compared with age- and sex-matched wild-type (WT) controls. Blood pressure and heart rate were recorded by a noninvasive, computerized tail-cuff system. Oral glucose and intraperitoneal insulin tolerance tests were performed. Serum cholesterol levels were measured by a combined quantitative colorimetric assay. Plasma adiponectin, C-reactive protein (CRP), insulin, interleukin-6 (IL-6), leptin, resistin, and tumor necrosis factor-α (TNF-α) were measured by multiplexed ELISA. MetS-Tg mice displayed significantly increased body weight, central obesity, and elevated blood pressure at all three ages compared with WT mice. Elevated serum cholesterol was associated with higher triglycerides and LDL/VLDL cholesterol particles and was accompanied by a decrease in HDL and histological evidence of fatty liver. MetS-Tg mice of all ages showed impaired glucose tolerance. At 12 mo, MetS-Tg mice had elevated plasma levels of CRP, IL-6, leptin, and TNF-α, but resistin levels were largely unchanged. We now report that this combination of gene knockouts produces a novel strain of mice that display the diverse clinical features of the metabolic syndrome, including central obesity, progressive hypertension, an adverse serum lipid profile, fatty liver, glucose intolerance, insulin resistance, and evidence of an inflammatory state.     

代谢调衡饮治疗代谢综合征的临床疗效观察

目的:考察代谢调衡饮治疗代谢综合征的临床疗效。方法:将60例代谢综合征患者随机分为试验组和对照组,对照组口服卡托普利和二甲双胍,试验组在此基础上加服代谢调衡饮,疗程3个月,观察两组治疗前后体重指数、血压、血糖、血脂等指标变化。结果:试验组有效率明显高于对照组(P<0.05)。与对照组相比,试验组患者治疗后体重指数、血压、血糖、血脂指标改善更明显(P<0.05 or P<0.01)。结论:代谢调衡饮对代谢综合征患者具有减重降压,降糖调脂功效,是干预代谢调衡饮的有效方剂。     

虎眼万年青多糖降血糖作用的研究

目的:研究虎眼万年青多糖对四氧嘧啶诱导的糖尿病小鼠的降糖作用以及对糖尿病相关特征的影响。方法:采用腹腔注射四氧嘧啶致糖尿病小鼠模型;分成阳性药物组、模型对照组、空白对照组、虎眼万年青多糖高、中、低剂量组,连续给药14d,观察糖尿病小鼠的体重、血糖水平、总胆固醇(TG)和甘油三脂(TC)的变化。结果:经灌胃给药14d后,与空白对照组比较,模型组小鼠体质量呈下降趋势(P0.01),血糖值(P0.01)、总胆固醇TG(P0.01)、甘油三酯TC(P0.01)均明显上升;与模型组比较,虎眼万年青多糖高、中剂量组能有效降低糖尿病小鼠的血糖水平(P0.01),总胆固醇TG(P0.01),甘油三脂TC(P0.01),并且虎眼万年青多糖高剂量组可缓解糖尿病小鼠体重减轻症状(P0.01),而低剂量组作用效果不明显(P0.05)。结论:虎眼万年青多糖能够降低四氧嘧啶致糖尿病小鼠血糖水平,改善血脂代谢紊乱。     

Hyperglycemia and hyperlipidemia are associated with endothelial dysfunction during the development of type 2 diabetes

Diabetes mellitus impairs endothelial function, which can be considered as the hallmark in the development of cardiovascular diseases. Hyperglycemia, hyperinsulinemia, and hyperlipidemia are believed to contribute to endothelial dysfunction. In the present study, we investigated the possible links among these plasma metabolic markers and endothelial function in a mouse model during the development of type 2 diabetes. C57BL/6J-Lepob/ob mice at 8, 12, and 16 weeks were used to study endothelial function during the establishment of type 2 diabetes. Endothelial function was accessed in vitro in the thoracic aorta by measuring acetylcholine (ACh)-stimulated vasodilatation. Blood plasma was obtained for the measurements of glucose, insulin, triglycerides, and cholesterol levels. Correlation and multiple regression analysis revealed strong negative associations between the ACh responsiveness and the plasma levels of glucose, insulin, and lipid profiles at the age of 8 weeks. Associations were observed at neither older age nor in C57BL/6J mice. In conclusion, the increase in plasma levels of glucose, insulin, and lipids is associated with the impairment of the endothelial function during the early stage of the development of type 2 diabetes. The loss of correlation at an older age suggests multifactorial regulation of endothelial function and cardiovascular complications at later stages of the disease.     

GAS6 / AXL 信号通路失活对小鼠能量代谢的影响简

目的 研究小鼠生长停滞特异蛋白6（growth arrest-specific gene 6,GAS6）信号通路的失活对维持机体能量代谢稳态的影响.方法 以GAS6主要受体Axl基因敲除（Axl-/-）小鼠及其野生型（Axl＋/＋）小鼠为研究对象,比较两组动物基础血糖值、血脂四项指标、脂肪系数及骨骼肌中糖代谢信号蛋白PI3K、AKT与葡萄糖转运蛋白4（glucose transporter 4,GLUT4）基因表达水平及其蛋白磷酸化水平间的差异;同时检测人工诱发2型糖尿病（type 2 diabetes mellitus,T2DM）造模前后小鼠血清GAS6蛋白水平与T2DM模型成模率的改变之间是否存在相关性.结果 Axl-/-小鼠血脂出现异常波动,且脂肪沉积率显著高于野生型小鼠（P＆lt;0.01）.Axl-/-小鼠血糖调节能力受损,其空腹血糖值显著高于野生型,骨骼肌Glut4的mRNA水平升高,而PI3K、AKT和GLUT4蛋白的磷酸化水平均略有下降.经人工诱发T2DM后,Axl＋/＋和Axl-/-小鼠血浆中GAS6浓度均显著低于各自对照组,且Axl-/-小鼠T2DM模型的成模率是Axl＋/＋小鼠的2倍（P＆lt;0.01）.结论 GAS6/AXL信号通路的激活在一定程度上降低血糖和抑制脂肪沉积.     

Impaired insulin sensitivity and elevated ectopic fat in healthy obese vs. nonobese prepubertal children

Insulin sensitivity is impaired and ectopic fat (accretion of lipids outside of typical adipose tissue depots) increased in obese adults and adolescents. It is unknown how early in life this occurs; thus, it is important to evaluate young children to identify potential factors leading to the development of metabolic syndrome. We examined an ethnically diverse cohort of healthy, exclusively prepubertal children (N = 123; F = 57, M = 66; age 8.04 ± 0.77 years) to examine differences in insulin sensitivity and ectopic and visceral fat deposition between obese and nonobese youth. Obesity was categorized by age- and sex-adjusted BMI z-scores (nonobese = z-score <2 (N = 94) and obese = z-score ≥2 (N = 29)). Insulin sensitivity was assessed by both a frequently sampled intravenous glucose tolerance test (S(i)) and the homeostatic model assessment of insulin resistance (HOMA(IR)). Intramyocellular lipids (IMCLs) from soleus and intrahepatic lipids (IHLs) were assessed by magnetic resonance spectroscopy, visceral adipose tissue (VAT) by magnetic resonance imaging, and total body fat by dual-energy X-ray absorptiometry. We also examined serum lipids (total cholesterol, triglycerides, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol) and blood pressure (diastolic and systolic). Obese children exhibited significantly lower S(i) (5.9 ± 5.98 vs. 13.43 ± 8.18 (mμ/l)(-1)·min(-1), P = 0.01) and HDL-C and higher HOMA(IR) (1.68 ± 1.49 vs. 0.63 ± 0.47, P < 0.0001), IMCL (0.74 ± 0.39 vs. 0.44 ± 0.21% water peak, P < 0.0001), IHL (1.49 ± 1.13 vs. 0.54 ± 0.42% water peak, P < 0.0001), VAT (20.16 ± 8.01 vs. 10.62 ± 5.44 cm(2), P < 0.0001), total cholesterol, triglycerides, low-density lipoprotein cholesterol, and systolic blood pressure relative to nonobese children. These results confirm significantly increased ectopic fat and insulin resistance in healthy obese vs. nonobese children prior to puberty. Excessive adiposity during early development appears concomitant with precursors of type 2 diabetes and the metabolic syndrome.     

Variation in plasma biochemical parameters in captive adult red-legged partridges (Alectoris rufa) during daylight hours

Blood biochemical parameters may provide useful information about the physical condition of the individual, making them a useful tool in ecological studies. However, to avoid biases, factors affecting circulating levels of plasma metabolites must be investigated. In this paper, we analyse the effect of daytime sampling hour on seven plasma metabolites in adult red-legged partridges (Alectoris rufa) with free access to food during the breeding season. We found that sampling hour affected circulating levels of glucose and triglycerides but not those of cholesterol, total protein, uric acid, urea or albumin. A sex effect was found only for glucose, uric acid, urea and triglycerides. Repeated sampling affected all the parameters studied. These results suggest that the effect of sex, sampling hour and repeated sampling should be carefully controlled for (methodologically or by statistical procedures) to avoid undesirable sources of error at least in some blood parameters.     

Gender-associated differences in metabolic syndrome-related parameters in Göttingen minipigs

Gender-associated differences in pathophysiology and treatment of disease are an evolving area in human medicine that should be addressed in animal models. The aim of this study was to characterize gender differences in metabolic parameters of G?ttingen minipigs and to determine which gender has the metabolic profile that is most appropriate as a model for human metabolic syndrome. Blood samples were collected from fasted, lean male and female G?ttingen minipigs at 8 wk and 8 mo of age. Samples were analyzed for glucose, fructosamine, insulin, C-peptide, glucagon, triglycerides, total cholesterol, high-density lipoprotein cholesterol (HDL-c), free fatty acids, leptin, testosterone, and 17beta-estradiol. Insulin sensitivity and beta cell function were estimated by homeostasis model assessment and degree of obesity by measuring the abdominal circumference. Male minipigs had higher concentrations of both testosterone and estradiol. Female minipigs had a larger abdominal circumference and higher concentrations of C-peptide, insulin, triglyceride, total cholesterol, HDL-c and leptin but a lower concentration of free fatty acids and lower HDL-c:total cholesterol ratio. Compared with male minipigs, female minipigs were more insulin-resistant and had a higher beta-cell function. No gender-associated differences were found in any of the other investigated parameters. In conclusion, female minipigs were more obese and insulin-resistant and had a more atherogenic plasma profile than did their male counterparts and therefore may be better models for metabolic syndrome. Their high concentrations of both testosterone and estradiol may protect male minipigs from obesity and metabolic disturbances.     

microRNA-30c reduces plasma cholesterol in homozygous familial hypercholesterolemic and type 2 diabetic mouse models

High plasma cholesterol levels are found in several metabolic disorders and their reductions are advocated to reduce the risk of atherosclerosis. A way to lower plasma lipids is to curtail lipoprotein production; however, this is associated with steatosis. We previously showed that microRNA (miR)-30c lowers diet-induced hypercholesterolemia and atherosclerosis in C57BL/6J and Apoe^−/− mice. Here, we tested the effect of miR-30c on plasma lipids, transaminases, and hepatic lipids in different mouse models. Hepatic delivery of miR-30c to chow-fed leptin-deficient (ob/ob) and leptin receptor-deficient (db/db) hypercholesterolemic and hyperglycemic mice reduced cholesterol in total plasma and VLDL/LDL by ∼28% and ∼25%, respectively, without affecting triglyceride and glucose levels. And these mice had lower plasma transaminases and creatine kinase activities than controls. Moreover, miR-30c significantly lowered plasma cholesterol and atherosclerosis in Western diet-fed Ldlr^−/− mice with no effect on plasma triglyceride, glucose, and transaminases. In these studies, hepatic lipids were similar in control and miR-30c-injected mice. Mechanistic studies showed that miR-30c reduced hepatic microsomal triglyceride transfer protein activity and lipid synthesis. Thus miR-30c reduced plasma cholesterol in several diet-induced and diabetic hypercholesterolemic mice. We speculate that miR-30c may be beneficial in lowering plasma cholesterol in different metabolic disorders independent of the origin of hypercholesterolemia.     

Testosterone and Regional Fat Distribution

The effects of testosterone treatment of abdominally obese men have been assessed by evaluating the following parameters: The metabolic activity of different adipose tissue regions in vivo (using lipid label as a tracer) and in vitro (measuring lipoprotein lipase(LPL) activity), the total and visceral adipose tissue mass, insulin sensitivity, fasting blood glucose, blood lipids, and blood pressure as well as prostate volume. Middle-aged men with abdominal obesity were treated with transdermal administration of testosterone (T), dihydrotestosterone (DHT) or placebo (P) during 9 months. The study was double-blind. Treatment with T was followed by an inhibited uptake of lipid label in adipose tissue triglycerides, a decreased LPL-activity and an increased turn-over rate of lipid label in the abdominal adipose tissue region in comparisons with the DHT and P groups. These effects on adipose tissue metabolism were not detected in the femoral adipose tissue region in any of the groups. T treatment was also followed by a specific decrease of visceral fat mass (measured by CT-scan), by increased insulin sensitivity (measured with the euglycemic glucose clamp), by a decrease in fasting blood glucose, plasma cholesterol and triglycerides as well as a decrease in diastolic blood pressure. In the DHT group an increased visceral mass was detected. No other changes in these variables were found in the DHT and P groups. There were no detectable changes in prostate volume (measured by ultra-sound), prostate specific antigen concentration, genito-urinary history or urinary flow measurements in any of the groups. It is suggested that T substitution to a selected group of men results in general metabolic and circulatory improvements. The prostate area needs further careful attention.     

Blood analysis in newborn donkeys: hematology,biochemistry, and blood gases analysis

The knowledge of reference ranges for hematologic, biochemical, and blood gas parameters in the different species and the influence of breed and age on them is a fundamental tool for the clinician. For this reason, the aim of this study was to evaluate the age-related changes of hematologic and biochemical parameters in Martina Franca donkey foals during the first 3 weeks of life and of blood gases during the first 24 hours of age. Fifteen healthy donkey foals were enrolled; blood samples were collected from each foal at 10 minutes after birth, 1 hour after the first and second suckles, 12 and 24 hours after birth, daily from Day 2 to 7, and at Days 10, 14, and 21 of life. Erythrocytes, leukocytes, and platelets counts were assessed; also metabolic (alanine aminotransferase, aspartate aminotransferase, gamma glutamyl transferase, creatinphospokinase, lactate dehydrogenase, alkaline phosphatase, glucose, blood urea nitrogen, creatinine, total proteins, albumins, cholesterol, and total bilirubin) and electrolytic parameters (Ca, P, Mg, Na, K, and Cl) were evaluated. Finally, blood gases and metabolic parameters (pH, pCO₂, pO₂, sO₂, TCO₂, HCO₃, lactate, and base excess) on venous blood were assessed with a portable analyzer. A statistical analysis to evaluate the influence of age and sex was performed. Several differences were found between sampling times, demonstrating that age influences these parameters. Moreover differences were found compared with data reported in literature for donkey foals of another species, horse foals, and adult donkeys. Although a great interindividual variation for some parameters exists, this study demonstrated that interval references should be addressed not only to different species, but also to specific breeds and to the neonatal period.     

Chromium picolinate and conjugated linoleic acid do not synergistically influence diet- and exercise-induced changes in body composition and health indexes in overweight women

This study assessed the effects of combined chromium picolinate (CP) and conjugated linoleic acid (CLA) supplementation on energy restriction and exercise-induced changes in body composition, glucose metabolism, lipid lipoprotein profile and blood pressure in overweight, premenopausal women. For 12 weeks, 35 women [age 36+/-1 years (mean+/-S.E.M.); BMI 28.0+/-0.5 kg/m2] were counseled to consume a 2092 kJ/day (500 kcal/day) energy deficit diet and performed 30 min of moderate-intensity walking or jogging 5 days/week. The women were randomly assigned to ingest either CP-CLA [400 mug chromium (Cr), 1.8 g CLA in 2.4 g tonalin oil, n=19] or placebo (<0.1 microg Cr, 2.4 g canola oil, n=16). Compared to baseline, urinary Cr excretion increased 22-fold, plasma CLA isomer 18:2 (c9,t11) content increased 79% and plasma CLA isomer 18:2 (t10,c12) became detectable in CP-CLA and were unchanged in Placebo. Over time, body weight decreased 3.5+/-0.5% (CP-CLA -2.6+/-0.5; placebo -2.5+/-0.5 kg) and fat mass decreased 8.9+/-1.3% (CP-CLA -2.7+/-0.5, placebo -2.4+/-0.5 kg), with no differences in responses between groups. Fasting blood hemoglobin A1c, plasma glucose and insulin, a homeostatic assessment of insulin resistance, serum total cholesterol (CHOL), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol, triacylglycerol (TG), CHOL/HDL ratio, TG/HDL ratio and sitting systolic and diastolic blood pressures were not changed over time or influenced by CP-CLA. The use of a combined CP and CLA supplement for 3 months does not affect diet- and exercise-induced changes in weight and body composition or improve indexes of metabolic and cardiovascular health in young overweight women.     

Ethnic differences in body composition and other markers of cardiovascular disease risk: study in matched Haitian and White subjects from Quebec

Objectives: People of African descent may be at greater risk of metabolic syndrome (MS) compared with whites. We examined the associations among MS markers, body composition, and resting metabolic rate (RMR) in black Haitians and in white subjects living in Quebec, Canada. Research Methods and Procedures: Forty randomly selected Haitians were matched with 40 white subjects for age, sex, and BMI. Glycemic status and insulin resistance were assessed based on a 3‐hour glucose tolerance test. Blood lipids, blood pressure, abdominal fat (computed tomography), and waist circumference (WC) were measured. RMR was estimated by indirect calorimetry. Results: Triglycerides were significantly correlated with blood pressure only in Haitians and with the area under the curve for insulin only in whites. Haitians had significantly (p < 0.05) lower triglycerides and higher high‐density lipoprotein‐cholesterol concentrations but higher blood pressure than whites at any given WC value. General linear models showed that Haitians had less visceral adipose tissue than whites for the same WC. RMR was lower among Haitians for any given value of BMI or WC than in whites. Also, WC was more strongly associated with glucose area under the curve and to log‐homeostasis model assessment in white than in Haitian subjects. Discussion: The MS may be ethnospecific in its features and etiology. The standard anthropometric indices of obesity may not be as effective in populations of African descent compared with whites, unless appropriate cut‐off values are defined.     

Effects of oocyte vitrification on the behaviors and physiological indexes of aged first filial generation mice

To evaluate the long-term effects of oocyte cryopreservation on the health of the first filial generation (F1), we used B6D2F1 mice for oocyte collection, in vitro fertilization, and breeding. The female F1 mice born from the offspring of fresh mature oocytes (control group) and from the offspring of vitrified oocytes with traditional vitrification medium (VM group) and new improved vitrification medium (2P10E7D group) were maintained until 14–15 months of age for behavioral tests and 16–17 months of age for physiological analyses. Behavioral indexes, including anxiety-like status, discrimination ability, learning and memory ability, were investigated. Physiological indexes including body weight, body fat, heart rate, blood pressure, and blood lipids were also analyzed. In our results, the behavioral indexes, body weight, body fat, heart rate, blood pressure, total cholesterol (TC), high-density lipoprotein cholesterol (HDL), and low-density lipoprotein cholesterol (LDL) did not show significant differences among the three groups. However, the triglyceride (TG) level of the VM group was higher than that of the 2P10E7D group. Moreover, compared with the control group, both the VM group and the 2P10E7D group showed greatly increased diastolic blood pressure. This study is the first to report that oocyte vitrification might affect metabolic physiological indexes via transgenerational inheritance rather than behaviors related to anxiety-like status and cognitive ability. Furthermore, different vitrification media might have differential transgenerational effects.     

Effects of early‐life exposure to Western diet and wheel access on metabolic syndrome profiles in mice bred for high voluntary exercise

Experimental studies manipulating diet and exercise have shown varying effects on metabolic syndrome components in both humans and rodents. To examine the potential interactive effects of diet, exercise and genetic background, we studied mice from four replicate lines bred (52 generations) for high voluntary wheel running (HR lines) and four unselected control lines (C). At weaning, animals were housed for 60 days with or without wheels and fed either a standard chow or Western diet (WD, 42% kcal from fat). Four serial (three juvenile and one adult) blood samples were taken to measure fasting total cholesterol (TC), high‐density lipoprotein cholesterol (HDL‐C), triglycerides and glucose. Western diet was obesogenic for all mice, even after accounting for the amount of wheel running and kilojoules consumed. Western diet significantly raised glucose as well as TC and HDL‐C concentrations. At the level of individual variation (repeatability), there was a modest correlation (r = 0.3–0.5) of blood lipids over time, which was reduced with wheel access and/or WD. Neither genetic selection history nor wheel access had a statistically significant effect on blood lipids. However, HR and C mice had divergent ontogenetic trajectories for body mass and caloric intake. HR mice also had lower adiposity, an effect that was dependent on wheel access. The environmental factors of diet and wheel access had pronounced effects on body mass, food consumption and fasting glucose concentrations, interacting with each other and/or with genetic strain. These data underscore the importance (and often unpredictable nature) of genotype‐by‐environment and environment‐by‐environment interactions when studying body weight regulation.     

Effect of chromium niacinate and chromium picolinate supplementation on lipid peroxidation, TNF-alpha, IL-6, CRP, glycated hemoglobin, triglycerides, and cholesterol levels in blood of streptozotocin-treated diabetic rats

Chromium (Cr(3+)) supplementation facilitates normal protein, fat, and carbohydrate metabolism, and is widely used by the public in many countries. This study examined the effect of chromium niacinate (Cr-N) or chromium picolinate (Cr-P) supplementation on lipid peroxidation (LP), TNF-alpha, IL-6, C-reactive protein (CRP), glycosylated hemoglobin (HbA(1)), cholesterol, and triglycerides (TG) in diabetic rats. Diabetes (D) was induced in Sprague-Dawley rats by streptozotocin (STZ) (ip, 65 mg/kg BW). Control buffer, Cr-N, or Cr-P (400 microg Cr/kg BW) was administered by gavages daily for 7 weeks. Blood was collected by heart puncture using light anesthesia. Diabetes caused a significant increase in blood levels of TNF-alpha, IL-6, glucose, HbA(1), cholesterol, TG, and LP. Compared with D, Cr-N supplementation lowered the blood levels of TNF-alpha (P=0.04), IL-6 (P=0.02), CRP (P=0.02), LP (P=0.01), HbA(1) (P=0.02), TG (P=0.04), and cholesterol (P=0.04). Compared with D, Cr-P supplementation showed a decrease in TNF-alpha (P=0.02), IL-6 (P=0.02), and LP (P=0.01). Chromium niacinate lowers blood levels of proinflammatory cytokines (TNF-alpha, IL-6, CRP), oxidative stress, and lipids levels in diabetic rats, and appears to be a more effective form of Cr(3+) supplementation. This study suggests that Cr(3+) supplementation can lower the risk of vascular inflammation in diabetes.     

Seasonal variations in the intermediate metabolism of Parastacus varicosus (Crustacea, Decapoda, Parastacidae)

The aim of this study was to analyze the seasonal variations in the metabolism of Parastacus varicosus and examine the possible relationships to its reproduction. Animals were sampled (9 h to 10 h) in each month in the Gravataí River, RS, Brazil. Haemolymph samples were collected from each crayfish in the field for determination of glucose, total proteins, total lipids, and total cholesterol. Hepatopancreas, abdominal muscle, and gonads were removed for determination of glycogen, total proteins, total lipids, and total cholesterol. ANOVA revealed significant seasonal differences in the biochemical composition of all tissues studied; when the sexes were compared these parameters did not show any significant difference in the hepatopancreas and muscle. However, in haemolymph we observed significant variation only in cholesterol and lipid levels. The results suggest that the metabolic variability is related to the stage of maturation of the gonads, in females, where the hepatopancreas and other tissue studies can store and transfer reserves to support maturation to complement the food intake. Variations in the gonadosomatic and hepatosomatic indices suggest that reproduction occurs principally in summer. As in other decapods, abiotic factors such as water temperature, oxygen content, etc. influence the intermediate metabolism.