Peri-conceptional changes in maternal exposure to sewage sludge chemicals disturbs fetal thyroid gland development in sheep

Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Genetic and Metabolic Determinants of Human Epigenetic Variation

Peer reviewed

Somatostatin agonist pasireotide promotes a physiological state resembling short-day acclimatization in the photoperiodic male Siberian hamster (Phodopus sungorus)

Peer reviewed

Obesity : How dangerous is weight gain between pregnancies?

Peer reviewed

When group members go against the grain : an ironic interactive effect of group identification and normative content on healthy eating

Acknowledgements The research leading to these results has been funded by a Tandem Grant from the European Health Psychology Society/CREATE, awarded to the first and second author. The funder had no involvement in the study design, collection or analysis of data, writing the report, or the decision to submit this manuscript for publication.

Vagal blocking for obesity control : a possible mechanism-of-action

Peer reviewed

Epigenetics and developmental programming of welfare and production traits in farm animals

Acknowledgements Financial support for composing this article was obtained from the Agriculture and Horticulture Development Board (AHDB, Beef and Lamb), UK. Concept of review was also initiated from discussions originating from EU COST Action FA1201, Epiconcept: Epigenetics and Periconception Environment

Obesity : How dangerous is weight gain between pregnancies?

Peer reviewed

Placental vascularity and markers of angiogenesis in relation to prenatal growth status in overnourished adolescent ewes

Acknowledgments Supported by the Wellcome Trust project grant 088208 (DJC), Wellbeing of Women research training fellowship 318 (DJC), Scottish Government Work package 4.2 (JMW, JSM and RPA), National Institute for Health Research University College London Hospitals Biomedical Research Centre (ALD) and Hatch ProjectND01748 (DAR).

A Computer Model of Drafting Effects on Collective Behavior in Elite 10,000 m Runners

Purpose Drafting in cycling influences collective behaviour of pelotons. Whilst evidence for collective behaviour in competitive running events exists, it is not clear if this results from energetic savings conferred by drafting. This study modelled the effects of drafting on behavior in elite 10,000 m runners. Methods Using performance data from a men’s elite 10,000 m track running event, computer simulations were constructed using Netlogo 5.1 to test the effects of three different drafting quantities on collective behaviour: no drafting, drafting to 3m behind with up to ~8% energy savings (a realistic running draft); and drafting up to 3m behind with up to 38% energy savings (a realistic cycling draft). Three measures of collective behaviour were analysed in each condition; mean speed, mean group stretch (distance between first and last placed runner), and Runner Convergence Ratio (RCR) which represents the degree of drafting benefit obtained by the follower in a pair of coupled runners. Results Mean speeds were 6.32±0.28m.s-1, 5.57±0.18 m.s-1, and 5.51±0.13 m.s-1 in the cycling draft, runner draft, and no draft conditions respectively (all P<0.001). RCR was lower in the cycling draft condition, but did not differ between the other two. Mean stretch did not differ between conditions. Conclusions Collective behaviours observed in running events cannot be fully explained through energetic savings conferred by realistic drafting benefits. They may therefore result from other, possibly psychological, processes. The benefits or otherwise of engaging in such behavior are, as yet, unclear.

White Adipose Tissue Re-growth after Partial Lipectomy in High Fat Diet Induced Obese Wistar Rats

The effects of partial removal of epididymal (EPI) and retroperitoneal (RET) adipose tissues (partial lipectomy) on the triacylglycerol deposition of high fat diet induced obese rats were analyzed, aiming to challenge the hypothesized body fat regulatory system. Male 28-day-old wistar rats received a diet enriched with peanuts, milk chocolate and sweet biscuits during the experimental period. At the 90th day of life, rats were submitted to either lipectomy (L) or sham surgery. After 7 or 30 days, RET, EPI, liver, brown adipose tissue (BAT), blood and carcass were obtained and analyzed. Seven days following surgery, liver lipogenesis rate and EPI relative weight were increased in L. After 30 days, L, RET and EPI presented increased lipogenesis, lipolysis and percentage of small area adipocytes. L rats also presented increased liver malic enzyme activity, BAT lipogenesis, and triacylglycerol and corticosterone serum levels. The partial removal of visceral fat pads affected the metabolism of high fat diet obese rats, which leads to excised tissue re-growth and possibly compensatory growth of non-excised depots at a later time.

A Palatable Hyperlipidic Diet Causes Obesity and Affects Brain Glucose Metabolism in Rats

Background We have previously shown that either the continuous intake of a palatable hyperlipidic diet (H) or the alternation of chow (C) and an H diet (CH regimen) induced obesity in rats. Here, we investigated whether the time of the start and duration of these feeding regimens are relevant and whether they affect brain glucose metabolism. Methods Male Wistar rats received C, H, or CH diets during various periods of their life spans: days 30-60, days 30-90, or days 60-90. Experiments were performed the 60th or the 90th day of life. Rats were killed by decapitation. The glucose, insulin, leptin plasma concentration, and lipid content of the carcasses were determined. The brain was sliced and incubated with or without insulin for the analysis of glucose uptake, oxidation, and the conversion of [1-14C]-glucose to lipids. Results The relative carcass lipid content increased in all of the H and CH groups, and the H30-60 and H30-90 groups had the highest levels. Groups H30-60, H30-90, CH30-60, and CH30-90 exhibited a higher serum glucose level. Serum leptin increased in all H groups and in the CH60-90 and CH30-90 groups. Serum insulin was elevated in the H30-60, H60-90, CH60-90, CH30-90 groups. Basal brain glucose consumption and hypothalamic insulin receptor density were lower only in the CH30-60 group. The rate of brain lipogenesis was increased in the H30-90 and CH30-90 groups. Conclusion These findings indicate that both H and CH diet regimens increased body adiposity independent treatment and the age at which treatment was started, whereas these diets caused hyperglycemia and affected brain metabolism when started at an early age.

Effects of Different Fatty Acids and Dietary Lipids on Adiponectin Gene Expression in 3T3-L1 Cells and C57BL/6J Mice Adipose Tissue

Obesity is positively correlated to dietary lipid intake, and the type of lipid may play a causal role in the development of obesity-related pathologies. A major protein secreted by adipose tissue is adiponectin, which has antiatherogenic and antidiabetic properties. The aim of this study was to evaluate the effects of four different high-fat diets (enriched with soybean oil, fish oil, coconut oil, or lard) on adiponectin gene expression and secretion by the white adipose tissue (WAT) of mice fed on a selected diet for either 2 (acute treatment) or 60 days (chronic treatment). Additionally, 3T3-L1 adipocytes were treated for 48 h with six different fatty acids: palmitic, linoleic, eicosapentaenoic (EPA), docosahexaenoic (DHA), lauric, or oleic acid. Serum adiponectin concentration was reduced in the soybean-, coconut-, and lard-enriched diets in both groups. Adiponectin gene expression was lower in retroperitoneal WAT after acute treatment with all diets. The same reduction in levels of adiponectin gene expression was observed in epididymal adipose tissue of animals chronically fed soybean and coconut diets and in 3T3-L1 cells treated with palmitic, linoleic, EPA, and DHA acids. These results indicate that the intake of certain fatty acids may affect serum adiponectin levels in mice and adiponectin gene expression in mouse WAT and 3T3-L1 adipocytes. The effects appear to be time dependent and depot specific. It is postulated that the downregulation of adiponectin expression by dietary enrichment with soybean oil or coconut oil may contribute to the development of insulin resistance and atherosclerosis.

Exercise Training in Rats Impairs the Replenishment of White Adipose Tissue after Partial Lipectomy

The aim of this study was to evaluate the effect of exercise training on the metabolism of rats following the partial removal of fat pads. Three-month-old male Wistar rats were subjected to the partial removal (L) of retroperitoneal white adipose tissue (RET) and epididymal white adipose tissue (EPI), or a sham operation (Sh). Seven days after surgery, both sets of rats were subdivided into exercised (LE or ShE) (swimming 90 min/day, 5 days/week, 6 weeks) and sedentary (LS or ShS) groups. Partial removal of the fat pads increased the lipogenesis rates in both the RET and EPI and decreased the weight and lypolysis rate of the EPI, while the RET weight was not significantly affected by lipectomy. In both lipectomized and sham-operated groups, exercise training caused a reduction in carcass lipid content, food intake, RET and EPI weights, and RET lipogenesis rate. On the other hand, the exercise training increased the percentage of diet-derived lipid accumulation in both tissues, either in sham and lipectomized rats. These results confirmed that regrowth is not uniform and depends on the particular fat pad that is excised. They also demonstrated that exercise training following the partial removal of fat pads modified adipose tissue metabolism, impaired the replenishment of adipose tissue, and decrease body adiposity.

Fructose Alters Adiponectin, Haptoglobin and Angiotensinogen Gene Expression in 3T3-L1 Adipocytes

Fructose- or sucrose-rich diets can cause insulin resistance and increase the risk of cardiovascular disease. Adipokines are correlated with the development of these diseases in obesity. We hypothesize that fructose and sucrose induce insulin resistance via effects on adipokine gene expression in adipocytes. This study analyzed the effect of fructose or glucose on adiponectin, haptoglobin, and angiotensinogen gene expression in 3T3-L1 adipocytes. Ten days after differentiation, the cells were pretreated with serum- and glucose-free medium. Twenty-four hours later, fructose or glucose (0, 5, 10, or 20 mmol) was added into the medium, and the cells were collected after a further 24 hours. Adiponectin, haptoglobin, and angiotensinogen gene expression were determined. Adiponectin gene expression increased when 10 or 20 mmol glucose was added compared with that observed for the non–hexose-treated cells. A similar effect occurred when 5 mmol fructose was added. Glucose (10 mmol) and fructose (20 mmol) stimulated haptoglobin gene expression in 3T3-L1 adipocytes compared with 0 mmol, with glucose producing a more pronounced effect. Although 20 mmol fructose caused an increase in angiotensinogen gene expression, glucose did not. In conclusion, in this study of 2 hexoses revealed an increase in adiponectin gene expression, suggesting that the effect of a glucose-rich diet on the development of insulin resistance is not related to the effect of these hexoses on adipocyte adiponectin gene expression. However, insulin resistance and cardiovascular disease promoted by fructose-rich diets could be partially related to the effect of fructose on adiponectin and angiotensinogen gene expression.