Slightly different metabolomic profiles are associated with high or low weights duck foie gras

Understanding the evolution of fatty liver metabolism of ducks is a recurrent issue for researchers and industry. Indeed, the increase in weight during the overfeeding period leads to an important change in the liver metabolism. However, liver weight is highly variable at the end of overfeeding within a batch of animals reared, force-fed and slaughtered in the same way. For this study, we performed a proton nuclear magnetic resonance ( 1 H-NMR) analysis on two classes of fatty liver samples, called low-weight liver (weight between 550 and 599 g) and high-weight liver (weight above 700 g). The aim of this study was to identify the differences in metabolism between two classes of liver weight (low and high). Firstly, the results showed that increased liver weight is associated with higher glucose uptake leading to greater lipid synthesis. Secondly, this increase is probably also due to a decline in the level of export of triglycerides and cholesterol from the liver by maintaining them at high hepatic concentration levels. Finally, the increase in liver weight could lead to a significant decrease in the efficiency of aerobic energy metabolism associated with a significant increase in the level of oxidative stress.

P0337PROTEOME CHANGES IN TUBULOINTERSTITIAL TISSUE OF PROGRESSIVE VS NON-PROGRESSIVE IGAN

Background and Aims IgA nephropathy (IgAN), a common glomerulonephritis worldwide, is associated with a significant risk of progression to end-stage renal failure. In the Oxford classification, tubular atrophy is an established important risk factor for the risk of progression but few studies have investigated possible tubulointerstitial markers and the mechanisms of progression in IgAN. The present study investigated changes in the tubulointerstitial proteome from patients with IgAN. Method Based on data from the Norwegian Kidney Biopsy Registry and the Norwegian Renal Registry, two groups were included: IgAN patients with (n=9) or without (n=16) progression to ESRD during 10 years. Tubulointerstitial tissue without discernible interstitial expansion or pronounced tubular alterations were microdissected, proteome was analysed using mass spectrometry and protein abundances were compared between groups. Results: Proteomic analyses quantified 2562 proteins with 2 or more unique peptides . Of these, 201 proteins had significant different abundance between progressive and non-progressive IgAN patients, 96 were more abundant and 105 less abundant. Periostin was the protein with the highest fold change between progressive and non progressive IgAN (fc 9.59, p<0.05). Proteins related to inflammation were more abundant and proteins involved in the aerobic energy metabolism and energy demanding ion channels were significantly less abundant in progressive vs non-progressive patients. Conclusion Our study describes extensive proteome changes of tubulo-interstitial tissue in patients with progressive IgAN and indicates several proteins and pathways that are important in the progression of the disease.

BST Stimulation Induces Atrophy and Changes in Aerobic Energy Metabolism in Rat Skeletal Muscles—The Biphasic Action of Endogenous Glucocorticoids

(1) The primary involvement in stress-induced disturbances in skeletal muscles is assigned to the release of glucocorticoids (GCs). The current study aims to investigate the impact of the biphasic action of the chronic stress response (CSR) induced by the electrical stimulation of the bed nucleus of the stria terminalis (BST) effects on muscle atrophy and aerobic energy metabolism in soleus (SOL) and extensor digitorum longus (EDL) muscles. (2) Male Wistar rats (n = 17) were used. The rats were divided randomly into three groups: the BST two weeks (ST2), four weeks (ST4), and the sham (SHM) electrically stimulated group. The plasma corticosterone (CORT) and irisin concentration were measured. Glucocorticoid and mineralocorticoid receptors (GR and MR), 11β-hydroxysteroid dehydrogenase type 1 and 2 (HSD11B1 and HSD11B2), atrogin-1, and insulin-like growth factor-1 (IGF-1) level were determined in SOL and EDL muscles. Citrate synthase (CS) activity was measured in both muscles. (3) We found elevated plasma concentration of CORT and irisin, raised the level of GR in SOL muscle, and the higher level of MR in both muscles in the ST4 group. The level of HSD11B1 was also higher in the ST4 group compared to the SHM group. Moreover, we observed increased activity of CS in SOL. (4) We suggest that biphasic action of the glucocorticoid induced by the CSR occurs and causes dysregulation of proteins involved in muscle atrophy and aerobic energy metabolism. Our findings potentially contribute to a better understanding of the mechanisms by which GCs and the CSR may regulate muscle atrophy and energy preservation of the red muscle.

Acclimation of juvenile Mugil liza Valenciennes, 1836 (Mugiliformes: Mugilidae) to different environmental salinities

Survival and physiological parameters associated with metabolism and osmoregulation were evaluated in juveniles of the Lebranche mullet Mugil liza acclimated to different water salinities (5, 10, 20, 30, and 40‰) for 15 days. Room temperature (25ºC) and photoperiod (12L:12D) were fixed. Fish were fed twice-a-day with commercial diet (28% crude protein) until satiation. After acclimation, whole body oxygen consumption was measured and fish were euthanized and sampled for blood, gills, and liver. Whole body oxygen consumption and plasma osmolality did not change in the range of salinities tested. The isosmotic point was estimated as 412.7 mOsmol kg-1 (13.5‰). Gill Na+,K+-ATPase activity tended to be lower at 20 and 30‰, while liver glycogen content was significantly higher at 20‰ than at 5 and 40‰. These results indicate that juvenile M. liza is able to acclimate for a short-period of time (15 days) to a wide range of salinities (5-40‰). This condition is achieved through adjustments in gill Na+,K+-ATPase activity and carbohydrate metabolism to regulate plasma osmolality and aerobic/energy metabolism. Therefore, our findings support the idea of catching juveniles M. liza in sea water and rear them in estuarine and marine waters.

Physiological responses and energy expenditure during competitive fencing

Fencing is an Olympic sport in which athletes fight one against one using bladed weapons. Contests consist of three 3-min bouts, with rest intervals of 1 min between them. No studies investigating oxygen uptake and energetic demand during fencing competitions exist, thus energetic expenditure and demand in this sport remain speculative. The aim of this study was to understand the physiological capacities underlying fencing performance. Aerobic energy expenditure and the recruitment of lactic anaerobic metabolism were determined in 15 athletes (2 females and 13 males) during a simulation of fencing by using a portable gas analyzer (MedGraphics VO2000), which was able to provide data on oxygen uptake, carbon dioxide production and heart rate. Blood lactate was assessed by means of a portable lactate analyzer. Average group energetic expenditure during the simulation was (mean ± SD) 10.24 ± 0.65 kcal·min−1, corresponding to 8.6 ± 0.54 METs. Oxygen uptakeand heart rate were always below the level of anaerobic threshold previously assessed during the preliminary incremental test, while blood lactate reached its maximum value of 6.9 ± 2.1 mmol·L−1 during the final recovery minute between rounds. Present data suggest that physical demand in fencing is moderate for skilled fencers and that both aerobic energy metabolism and anaerobic lactic energy sources are moderately recruited. This should be considered by coaches when preparing training programs for athletes.