Digestible energy content of pasture species in growing European wild boar (Sus scrofa L.).

The objectives were to determine the apparent energy digestibility of six pasture species frequently grazed by European wild boar (Sus scrofa L.) and to estimate the digestible energy (DE) consumption from pasture by grazing wild boar. Seven diets were prepared; a base diet (BD) which did not contain any pasture species, diets D1 to D5 which included 75% of the BD and 25% of the dried pasture species Lolium perenne (D1), Festuca arundinacea (D2), Agrostis capillaris (D3), Bromus staminius (D4) or Trifolium repens (D5) and D6 which contained 85% BD and 15% dried Plantago lanceolata. Seven purebred European wild boar (initial liveweight 24.4 ± 0.8 kg, average ± SEM) were given access to the diets following a Latin Square design. The animals received each diet for eight days, with faecal sampling on days 6, 7 and 8. The total apparent DE consumption from pasture by grazing wild boar was estimated using previously collected pasture consumption data from wild boar. The digestibility coefficients and DE contents of the pasture species ranged from 0.29 to 0.65, and 5.8 to 12.6 MJ/kg DM respectively, with L. perenne and P. lanceolata having the greatest digestibility coefficients and DE contents. The wild boar were estimated to satisfy between 52% and 142% of their maintenance energy requirements through pasture consumption. Grazing wild boar are able to utilise an important proportion of the energy present in pasture species.

Specific and sustained down-regulation of genes involved in fatty acid metabolism is not a hallmark of progression to cardiac failure in mice.

Preferential and specific down-regulation of genes involved in fatty acid (FA) uptake and metabolism is considered a hallmark of severe hypertrophic remodeling and progression to cardiac failure. Therefore, we investigated the time course of changes in cardiac metabolic gene expression (1) in mice subjected to regional myocardial infarction (MI) for 4 days, 1 month, or 3 months and (2) in mice overexpressing calcineurin (Cn) which initially develop concentric hypertrophy progressing after the age of 4 weeks to dilated cardiomyopathy and failure. In both models, hypertrophy was characterized by increased expression of beta-myosin heavy chain protein and atrial natriuretic factor mRNA, indicative of marked structural remodeling. Fractional shortening progressively decreased from 31% to 15.1% and 3.7% 1 and 3 months after MI, respectively. One month post-MI, the expression of several metabolic genes, i.e., acyl-CoA synthetase (-50%), muscle-type carnitine palmitoyl transferase 1 (-37%) and citrate synthase (-28%), was significantly reduced in the surviving myocardium. Despite overt signs of cardiac failure 3 months post-MI, the expression of these genes had returned to normal levels. In hearts of both 4- and 6-week-old Cn mice, genes involved in both FA and glucose metabolism and mitochondrial citrate synthase were down-regulated, reflecting an overall decline in metabolic gene expression, rather than a specific and preferential down-regulation of genes involved in FA uptake and metabolism. These findings challenge the concept that specific and sustained down-regulation of genes involved in FA uptake and metabolism represents a hallmark of the development of cardiac hypertrophy and progression to failure.

Chronic moderate hypoxia during in ovo development alters arterial reactivity in chickens.

We previously observed arterial sympathetic hyperinnervation and endothelial dysfunction in the chicken embryo after exposure to chronic hypoxia. We now investigate whether changes in arterial properties could also be observed at 14-15 weeks of life. Eggs of White Leghorn chicken were incubated under normoxic or moderately hypoxic (15% O2 from days 6-19 of a 21-day incubation) conditions. Experiments were performed at 14-15 weeks of life under standard conditions (Hm: males exposed to hypoxia; Hf: females exposed to hypoxia; Nm: males exposed to normoxia; Nf: females exposed to normoxia). Body weight at hatching and at 14-15 weeks was not affected by in ovo exposure to hypoxia. Mean arterial pressure and heart rate were not significantly altered by chronic in ovo hypoxia. However, isolated femoral arteries were more sensitive to electrical stimulation (frequency in Hz of half-maximal contraction, Hm: 1.62+/-0.33, Hf: 1.92+/-0.88, Nm: 2.49+/-0.49, Nf: 2.83+/-0.31) and pharmacological stimulation of peri-arterial sympathetic nerves (contraction in N/m in response to tyramine: Hm: 5.27+/-0.85, Hf: 4.10+/-0.9, Nm: 2.26+/-0.67, Nf: 3.65+/-0.51, p=0.07) after in ovo hypoxia. In side branches of the femoral artery, the effect of NO synthase blockade with L-NAME on contraction (in N/m) in response to high K+ (Hm: 0.35+/-0.91, Hf: 1.29+/-0.36, Nm: 2.88+/-0.19, Nf: 2.79+/-0.58) and on the sensitivity to acetylcholine (DeltapD2, H: 0.32+/-0.11, N: 0.62+/-0.05) was reduced after in ovo hypoxia. The present study shows that exposure to chronic moderate hypoxia during development affects the contractile and relaxing arterial responses of 14- to 15-week-old chickens. Although hypoxia did not lead to changes in blood pressure at this age, the observed effects on arterial sympathetic and endothelial function may represent early signs of future cardiovascular abnormalities.

Estrogenic activity of musk fragrances detected by the E-screen assay using human mcf-7 cells.

The widespread use of synthetic musk fragrances and the resultant presence of these substances and their metabolites in the aquatic environment (as well as their accumulation in human adipose tissue) raises the question of whether musk fragrances display endocrine and in particular estrogenic activity. A variety of musk fragrances were tested using the E-screen assay. A statistically significant increase in proliferation rate of human MCF-7 breast cancer cells was detected for two nitro musks (musk xylene, musk ketone), a major metabolite of musk xylene ( p-amino-musk xylene), and the polycyclic musk fragrance AHTN. This indicates that these substances do, in fact, demonstrate estrogenic activity. Coincubation with the antiestrogen tamoxifen showed that the increase in proliferation rate by the musk fragrances is estrogen receptor-mediated. It must be noted, however, that the effective estrogenic strength and estrogenic potency were low compared to 17 b-estradiol. The naturally occurring fragrance muscone from the group of macrocyclic musk fragrances, a group of substances that have not yet been well characterized in respect to their toxicological properties, has also been shown to be weakly estrogenically active in vitro. E-screen analysis showed that the nitro musk metabolites o-amino musk xylene and 2-amino-MK, the macrocyclic musk fragrances ethylene brassylate, ethylene dodecandioate, and cyclopentadecanolide, are not estrogenically active.

Application of the E-screen assay to test for oestrogenically active substances in swine feed.

A pig breeder in central Hesse (Germany) noticed the occurrence of enlarged vulvae in female piglets. Intoxication with oestrogenically active substances by contamination of two feed mixes ingested by the mother sows appeared to be a possible cause. Using a combined technique of the DFG analytical method S19 and the E-screen assay, two feed samples were found to contain powerful oestrogenically active compounds. By co-incubation with the anti-oestrogen tamoxifen it could be clearly demonstrated that the oestrogenic activity was mediated by the oestrogen receptor. These results demonstrate that use of the E-screen assay in combination with the DFG analytical method S19 provides a simple and readily usable prescreening method for the routine detection of oestrogenically active compounds in animal feed. The results from the E-screen assay show that the sows ingested 10-80 microg oestradiol equivalents per day in their feed. Because of the bioavailability of these substances, the oestrogenic active compounds seem to be transferred into the milk and passed to the piglets via suckling. The milk of the dam appears to contain this substance in biologically active form and at such high concentrations that the female piglets had enlarged vulvae.