Sevoflurane and isoflurane anesthesia induce redox imbalance, but only sevoflurane impairs vascular contraction.

Volatile anesthetics may cause vascular dysfunction; however, underlying effects are unclear. The aim of the present study was to investigate whether sevoflurane and isoflurane affect vascular function, nitric oxide (NO) bioavailability, and biomarkers of oxidative stress and inflammation. Wistar rats were divided into three experimental groups: Not anesthetized (control group) or submitted to anesthesia with isoflurane (Iso group) or sevoflurane (Sevo group). Hemodynamic parameters were monitored during anesthesia, and blood gas values and biochemical determinants were analyzed. Isometric contractions were recorded in aortic rings. Vasoconstriction induced by potassium chloride (KCl) and phenylephrine (Phe) were measured. No differences in hemodynamic parameters and blood gasses variables were observed. Impaired KCl and Phe-induced contractions were observed in endothelium-intact aorta of Sevo compared to Iso and Control groups. Redox imbalance was found in Sevo and Iso groups. Reduced NO bioavailability and increased activity of matrix metalloproteinase 2 (MMP-2) were observed in Sevo, but not in the Iso group. While reduced IL-10 and IL-1ß were observed in Sevo, increases in IL-1ß in the Iso group were found. Sevoflurane, but not isoflurane, anesthesia impairs vasocontraction, and reduced NO and cytokines and increased MMP-2 activity may be involved in vascular dysfunction after sevoflurane anesthesia.

Biochemical basis of differential selenium tolerance in arugula (Eruca sativa Mill.) and lettuce (Lactuca sativa L.).

Selenium (Se) biofortification in crops provides a valuable strategy to enhance human Se intake. However, crops vary greatly with their capacity in tolerating and metabolizing/accumulating Se, and the basis underlying such variations remains to be fully understood. Here, we compared the effects of Se and its analog S treatments on plant growth and biochemical responses between a Se accumulator (arugula) and a non-accumulator (lettuce). Arugula exhibited an increased biomass production in comparison with untreated controls at a higher selenate concentration than lettuce (20 µM vs. 10 µM Na2SeO4), showing better tolerance to Se. Arugula accumulated 3-folds more Se and S than lettuce plants under the same treatments. However, the Se/S assimilation as assessed by ATP sulfurylase and O-acetylserine (thiol)lyase activities was comparable between arugula and lettuce plants. Approximately 4-fold higher levels of Se in proteins under the same doses of Se treatments were observed in arugula than in lettuce, indicating that Se accumulators have better tolerance to selenoamino acids in proteins. Noticeably, arugula showed 6-fold higher ascorbate peroxidase activity and produced over 5-fold more glutathione and non-protein thiols than lettuce plants, which suggest critical roles of antioxidants in Se tolerance. Taken together, our results show that the elevated Se tolerance of arugula compared to lettuce is most likely due to an efficient antioxidant defense system. This study provides further insights into our understanding of the difference in tolerating and metabolizing/accumulating Se between Se accumulators and non-accumulators.

Increases in placental nitric oxide, but not nitric oxide-mediated relaxation, underlie the improvement in placental efficiency and antihypertensive effects of hydrogen sulphide donor in hypertensive pregnancy.

Dysregulation of hydrogen sulphide (H2 S) producing enzymes has been related to hypertensive pregnancy, and H2 S donor, sodium hydrosulphide (NaHS) exerts antihypertensive effects, modulates angiogenic factors production and acts as an antioxidant. Moreover, reduction in nitric oxide (NO) bioavailability is related to hypertensive pregnancy and H2 S may interact with NO, modulating its production. We aimed to investigate the NaHS effects in hypertension-in-pregnancy and also in feto-placental parameters. Female Wistar rats (200-250 g) were mated and desoxycorticosterone acetate injections followed by replacement of water by 0.9% saline solution were used to induce hypertensive pregnancy. Rats were divided into four groups: normal pregnant (Norm-Preg), pregnant + NaHS (Preg+NaHS), hypertensive pregnant (HTN-Preg) and HTN-Preg+NaHS. Systolic blood pressure was increased in HTN-Preg and this increase was blunted in HTN-Preg+NaHS. Fetal and placental weights were decreased in HTN-Preg animals, while fetal growth restriction was improved in HTN-Preg+NaHS. Placental weight was lower in HTN-Preg+NaHS than in HTN-Preg; however, placental efficiency was re-established in HTN-Preg+NaHS rats. We observed that a partial contribution of placental NO, but not changes in anti-angiogenic factors may mediate the increases in placental efficiency in HTN-Preg+NaHS. HTN-Preg presented thoracic aorta hyperreactivity to phenylephrine while NaHS treatment blunted this hyperreactivity, which seems not to be related to NO-mediated relaxation induced by acetylcholine. Therefore, changes in vascular responsiveness promoted by NaHS treatment may underlie the beneficial effects in systolic blood pressure and feto-placental parameters in our study.