Ninety-day oral toxicity studies on two genetically modified maize MON810 varieties in Wistar Han RCC rats (EU 7th Framework Programme project GRACE)

The GMO Risk Assessment and Communication of Evidence (GRACE; www.grace-fp7.eu) project is funded by the European Commission within the 7th Framework Programme. A key objective of GRACE is to conduct 90-day animal feeding trials, animal studies with an extended time frame as well as analytical, in vitro and in silico studies on genetically modified (GM) maize in order to comparatively evaluate their use in GM plant risk assessment. In the present study, the results of two 90-day feeding trials with two different GM maize MON810 varieties, their near-isogenic non-GM varieties and four additional conventional maize varieties are presented. The feeding trials were performed by taking into account the guidance for such studies published by the EFSA Scientific Committee in 2011 and the OECD Test Guideline 408. The results obtained show that the MON810 maize at a level of up to 33 % in the diet did not induce adverse effects in male and female Wistar Han RCC rats after subchronic exposure, independently of the two different genetic backgrounds of the event

One-year oral toxicity study on a genetically modified maize MON810 variety in Wistar Han RCC rats (EU 7th Framework Programme project GRACE)

The GRACE (GMO Risk Assessment and Communication of Evidence; www.grace-fp7.eu) project was funded by the European Commission within the 7th Framework Programme. A key objective of GRACE was to conduct 90-day animal feeding trials, animal studies with an extended time frame as well as analytical, in vitro and in silico studies on genetically modified (GM) maize in order to comparatively evaluate their use in GM plant risk assessment. In the present study, the results of a 1-year feeding trial with a GM maize MON810 variety, its near-isogenic non-GM comparator and an additional conventional maize variety are presented. The feeding trials were performed by taking into account the guidance for such studies published by the EFSA Scientific Committee in 2011 and the OECD Test Guideline 452. The results obtained show that the MON810 maize at a level of up to 33 % in the diet did not induce adverse effects in male and female Wistar Han RCC rats after a chronic exposure

Impact of ovariectomy, high fat diet, and lifestyle modifications on oxidative/antioxidative status in the rat liver

Aim To estimate the impact of high fat diet and estrogen deficiency on the oxidative and antioxidative status in the liver of the ovariectomized rats, as well as the ameliorating effect of physical activity or consumption of functional food containing bioactive compounds with antioxidative properties on oxidative damage in the rat liver. Methods The study was conducted from November 2012 to April 2013. Liver oxidative damage was determined by lipid peroxidation levels expressed in terms of thiobarbituric acid reactive substances (TBARS), while liver antioxidative status was determined by catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), glutathione reductase (GR) activities, and glutathione (GSH) content. Sixty-four female Wistar rats were divided into eight groups: sham operated and ovariectomized rats that received either standard diet, high fat diet, or high fat diet supplemented with cereal selenized onion biscuits or high fat diet together with introduction of physical exercise of animals. Results High fat diet significantly increased TBARS content in the liver compared to standard diet (P = 0.032, P = 0.030). Furthermore, high fat diet decreased the activities of CAT, GR, and GST, as well as the content of GSH (P < 0.050). GPx activity remained unchanged in all groups. Physical activity and consumption of cereal selenized onion biscuits showed protective effect through increased GR activity in sham operated rats (P = 0.026, P = 0.009), while in ovariectomized group CAT activity was increased (P = 0.018) in rats that received cereal selenized onion biscuits. Conclusion Feeding rats with high fat diet was accompanied by decreased antioxidative enzyme activities and increased lipid peroxidation. Bioactive compounds of cereal selenized onion biscuits showed potential to attenuate the adverse impact of high fat diet on antioxidative statu

Effects of high fat diet, ovariectomy, and physical activity on leptin receptor expression in rat brain and white fat tissue

Aim To evaluate in a rat animal model whether ovariectomy, high fat diet (HFD), and physical activity in the form of running affect leptin receptor (Ob-R) distribution in the brain and white fat tissue compared to sham (Sh) surgery, standard diet (StD), and sedentary conditions. Methods The study included 48 female laboratory Wistar rats (4 weeks old). Following eight weeks of feeding with standard or HFD, rats were subjected to either OVX or Sh surgery. After surgery, all animals continued StD or HFD for the next 10 weeks. During these 10 weeks, ovariectomy and Sh groups were subjected to physical activity or sedentary conditions. Free-floating immunohistochemistry and Western blot methods were carried out to detect Ob-R in the brain and adipose tissue. Results StD-ovariectomy-sedentary group had a greater number of Ob-R positive neurons in lateral hypothalamic nuclei than StD-Sh-sedentary group. There was no difference in Ob-R positive neurons in arcuatus nuclei between all groups. Ob-R distribution in the barrel cortex was higher in HFD group than in StD group. Ob-R presence in perirenal and subcutaneous fat was decreased in StD-ovariectomy group. Conclusion HFD and ovariectomy increased Ob-R distribution in lateral hypothalamic nuclei, but there was no effect on arcuatus nuclei. Our results are first to suggest that HFD, ovariectomy, and physical activity affect Ob-R distribution in the barrel cortex, which might be correlated with the role of Ob-R in election of food in rats

A novel way of liver preservation improves rat liver viability upon reperfusion

Background/aim: Currently, the liver is cold-preserved at 0~4 °C for experimental and clinical purposes. Here, we investigated whether milder hypothermia during the initial phase of the preservation period was beneficial for liver viability upon reperfusion. Methods: In the first set of experiments, rat livers were preserved either conventionally in clinically used histidine-trypthopan-ketoglutarate (HTK) solution (Group A: 45 min and Group B: 24 h) or by slow cooling HTK solution (from 13 °C to 3 °C) during the initial 45 min of preservation (Group C: 24 h). In the second set of experiments, additional groups of livers were evaluated: Group BB—preservation according to Group B and Group CC—preservation according to Group C. Further, some livers were preserved at 13 °C for 24 h. Livers were then reperfused using a blood-free perfusion model. Results: Bile production was approximately 2-fold greater in Group C compared to Group B. Alanine transaminase (ALT) and aspartate transaminase (AST) release into perfusate were 2~3-fold higher in Group B compared to Group C. No significant differences were found in ALT and AST release between Group C and Group A. Livers in Group CC compared to Group BB exhibited significantly lower portal resistance, greater oxygen consumption and bromosulfophthalein excretion into bile and lower lactate dehydrogenase (LDH) release into perfusate. Histological evaluation of tissue sections in Group BB showed parenchymal dystrophy of hepatocytes, while dystrophy of hepatocytes was absent in Group CC. Livers preserved at 13 °C for 24 h exhibited severe ischemic injury. Conclusion: These results suggest that the conventional way of liver preservation is not suitable at least for rat livers and that slow cooling of HTK solution during the initial phase of cold storage can improve liver viability during reperfusion

Sagittal (A) and coronal (B and C) drawings of the rat brain with the topography of brain nuclei and areas where <i>nephrectomized rats</i> responded with <i>losartan treatment</i> with moderate to high expressions of Fos as compared to <i>placebo-treated nephrectomized</i> animals.

<p>The rostro-caudal levels of the coronal sections are indicated on Fig. A). <i>Dark blue</i> = highly, <i>light blue = </i>moderately <i>elevated</i> Fos activation, <i>red = </i>highly, <i>light red</i> = moderately <i>depleted</i> Fos activation. (For the level of numerical changes <i>see </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0066543#pone-0066543-t002" target="_blank">Table 2</a>.) <i>Abbreviations and numbers: see</i> Fig. 1.</p

Sagittal (A) and coronal (B and C) drawings of the rat brain with the topography of brain nuclei and areas where neurons in <i>nephrectomized rats</i> responded to <i>moxodinine treatment</i> with moderate to high expressions of Fos as compared to <i>placebo-treated nephrectomized</i> animals.

<p>The rostro-caudal levels of the coronal sections are indicated on Fig. A). <i>Dark blue</i> = highly, <i>light blue = </i>moderately <i>elevated</i> Fos activation, <i>red = </i>highly, <i>light red</i> = moderately <i>depleted</i> Fos activation. (For the level of numerical changes <i>see </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0066543#pone-0066543-t002" target="_blank">Table 2</a>.) <i>Abbreviations and numbers: see</i> Fig. 1.</p

Characteristics of sham-operated and 4/6-nephrectomized (4/6NX) rats at sacrifice.

<p>Cl: clearance; AGE: advanced glycation end products-associated fluorescence of plasma; AU: arbitrary units; AOPPs: plasma advanced oxidation protein products; K-W: Kruskal-Wallis test;</p><p>+: p<0.05 vs. SHAM-PLAC;</p>*<p>: p<0.05 vs. 4/6NX-PLAC (Exact 2-sided Man-Whitney U-test with Bonferonni correction).</p