Narasin sodium

Membrane vesicles isolated from rabbit ventricular tissue rapidly accumulated Ca2+ when an outwardly directed Na+ gradient was formed across the vesicle membrane. Vesicles loaded internally with K+ showed only 10% of the Ca2+ uptake activity observed with Na+-loaded vesicles. Dissipation of the Na+ gradient with the monovalent cation exchange ionophores nigericin or narasin caused a rapid decline in Ca2+ uptake activity. The Ca2+-ionophore A23187 inhibited Ca2+ uptake by Na+-loaded vesicles and enhanced the rate of Ca2+ loss from the vesicles after uptake. Efflux of preaccumulated Ca2+ from the vesicles was stimulated 30-fold by the presence of 50 mM Na+ in the external medium. Na+-dependent uptake and efflux of Ca2+ were both inhibited by La3+. The results indicate that cardiac membrane vesicles exhibit Na+-Ca2+ exchange activity. Fractionation of the vesicles by density gradient centrifugation revealed a close correspondence between Na+-Ca2+ exchange activity and specific ouabain-binding activity among the various fractions. This relationship suggests that the observed Na+-Ca2+ exchange activity derives from the sarcolemmal membranes within the vesicle preparation.

Following a request from the European Commission, the Panel on Additives and Products or Substances used in Animal Feed (FEEDAP) was asked to deliver a scientific opinion on the additive consisting ofBacillus amyloliquefaciensDSM 25840 when used as technological additive (hygiene condition enhancer) in feed for all animal species. The product is intended for use in dry feeds at a minimum inclusion level of 1 × 108colony forming unit (CFU)/kg complete feedingstuffs. The bacterial speciesBacillus amyloliquefaciensDSM 25840 is considered by EFSA to be eligible for the qualified presumption of safety approach. As the identity of the strain has been clearly established and it did not show acquired resistance to antibiotics of human and veterinary importance, the use of the strain in animal nutrition is considered safe for the target species, consumers and the environment. No conclusions can be drawn on the skin/eye irritancy or skin sensitisation potential of the product. Exposure of users by inhalation is likely and the product should be considered a respiratory sensitiser. The Panel is not in the position to conclude on the efficacy ofBacillus amyloliquefaciensDSM 25840 when used in animal nutrition as hygiene condition enhancer due to lack of data.Bacillus amyloliquefaciensDSM 25840 is compatible with diclazuril, decoquinate and halofuginone. The data provided do not allow to conclude on the compatibility of the additive with monensin sodium, salinomycin sodium, narasin, robenidine hydrochloride and maduramicin ammonium.

Coccidiosis, an intestinal plasmodium infection, is a major infectious disease in poultry and rabbits. Eleven different coccidiostats are licensed in the EU for the prevention of coccidiosis in these animal species. According to their chemical nature and main biological activity, these compounds can be grouped as ionophoric (monensin, lasalocid sodium, salinomycin, narasin, maduramicin and semduramicin) or non-ionophoric (robenidine, decoquinate, nicarbazin, diclazuril, and halofuginone) substances. Coccidiostats are used as feed additives, mixed upon request into the compounded feed. During the technical process of commercial feed production, cross-contamination of feed batches can result in the exposure of non-target animals and induce adverse health effects in these animals due to a specific sensitivity of mammalian species as compared to poultry. Residue formation in edible tissues of non-target species may result in unexpected human exposure through the consumption of animal products. This review presents recent risk assessments performed by the Scientific Panel on Contaminants in the Food Chain (CONTAM) of the European Food Safety Authority (EFSA). The health risk to non-target species that would result from the consumption of cross-contaminated feed with coccidostats at levels of 2, 5 or 10% was found to be negligible for most animal species with the exception of salinomycin and monensin in horses because of the particular sensitivity for which toxicity may occur when cross-contamination exceeds 2% and 5% respectively. Kinetic data and tissue analyses showed that residues of coccidiostats may occur in the liver and eggs in some cases. However, the level of residues of each coccidiostat in edible animal tissues remained sufficiently low that the aggregate exposure of consumers would not exceed the established acceptable daily intake (ADI) of each coccidiostat. It could be concluded that technical cross-contamination of animal feeds would not be expected to adversely affect the health of consumers.