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“This study was undertaken to evaluate the protective efficacy of the antioxidants vitamin E and Trolox (a water-soluble vitamin E derivative) against the toxicity of microcystin-LR (MC-LR), Microcystis aeruginosa aqueous extract (CE), and a reference toxin, menadione sodium bisulfite (MSB), in Artemia franciscana nauplii. This was achieved by using the well-established brine shrimp bioassay. The experiment was conducted in 2 stages, with (1) 12-h mortality time course and (2) LC50 determination for 12- and 24-h exposures. Treatments consisted of MC-LR, CE, and MSB alone and with 4-h pretreatments

of either vitamin E or Trolox. Sensitivity of A. franciscana nauplii with 24-h LC50 values of 11 (10.1-12.1) mu g/ml for MSB and 9.5 (8.8-10.4) mu g/ml for MC-LR were in general agreement with values reported for Artemia sp. Both selleck chemicals llc antioxidant pretreatments resulted in significant reductions learn more in mortality of approximately 50% at 9 h postexposure when challenged by either 40 mu g/ml MC-LR or 20 mu g/ml MSB. In contrast, the antioxidant pretreatments offered little to no protection

from CE, suggesting that other uncharacterized bioactive compounds contributed to overall toxicity. The described bioassay is easily accessible, inexpensive, rapid, and complies with animal ethics guidelines of many countries, and thus provides a potential alternative to the mouse bioassay for the initial screening for chemoprotectants against MC-LR toxicity.”
“Exposure to fine particulate matter (PM, mean aerodynamic diameter <= 2.5 mu m) has been shown to be a risk factor for cardiovascular disease mortality and may contribute to acute coronary events such as myocardial infarction (MI). There is sufficient reason to believe that smaller particles, such as nanoparticles, might be even more detrimental than larger sized particles due to their increased surface area and higher pulmonary deposition. Our laboratory showed that nanoparticle inhalation impairs endothelium-dependent arteriolar vasodilation in skeletal muscle. However, Smoothened it is not known whether coronary

microvascular endothelial function is affected in a similar manner. Rats were exposed to filtered air (control) or TiO(2) nanoparticles (primary particle diameter, similar to 21 nm) via inhalation at concentrations that produced measured depositions (10 mu g) relevant to ambient air pollution. Subepicardial arterioles(similar to 150 mm in diameter) were isolated and responses to transmural pressure, flow-induced dilation (FID), acetylcholine (ACh), the Ca(2+) ionophore A23187, and sodium nitroprusside (SNP) were assessed. Myogenic responsiveness was preserved between groups. In addition, there was no difference in the vasodilation to SNP, signifying that smooth muscle sensitivity to nitric oxide (NO) is unaffected by nano-TiO(2) exposure.