Hyperbaric oxygen preconditioning (HBO-PC) has been proposed as a safe and practical approach for neuroprotection in ischemic stroke. However, it is not known whether HPO-PC can improve cognitive deficits induced by cerebral ischemia, and the mechanistic basis for any beneficial effects remains unclear. We addressed this in the present study using rats subjected to middle cerebral artery occlusion (MCAO) as an ischemic stroke model following HBO-PC. Cognitive function and expression of phosphorylated neurofilament heavy polypeptide (pNF-H) and doublecortin (DCX) in the hippocampus were evaluated 14 days after reperfusion and after short interfering RNA-mediated knockdown of sirtuin1 (Sirt1 ). HBO-PC increased pNF-H and DCX expression and mitigated cognitive deficits in MCAO rats. However, these effects were abolished by Sirt1 knockdown. Our
results suggest that HBO-PC can protect the brain from injury caused by ischemia-reperfusion and that Sirt1 is a potential molecular target for therapeutic approaches designed to minimize cognitive deficits caused by cerebral ischemia.
To investigate how bisulfite promotes photosynthesis, a pot experiment was conducted with rice (Oryza sativa L.) plants to determine Rubisco activity and content, and Rubisco activase (RCA) gene expression after spraying NaHSO3 on rice leaves. The NaHSO3 treatment promoted significantly net photosynthetic rate (PN), carboxylation efficiency, maximum carboxylation rate, ribulose-1,5-bisphosphate regeneration rate, initial Rubisco activity, and RCA protein and mRNA concentrations. Therefore, the NaHSO3 enhancement of PN could be directly attributed to induction of RCA gene expression both at the transcription and translation levels. Thus, the increased RCA regulated the initial Rubisco activity in vivo., Y. Chen, J.-H. Jin, Q.-S. Jiang, C.-L. Yu, J. Chen, L.-G Xu, D.-A. Jiang., and Obsahuje bibliografii
Plasma endothelin-1 (ET-1) levels are elevated in spinal cord injury (SCI), and ET-1 may be involved in the pathophysiology of this condition. However, its effects on contractile function of the heart of SCI rats are still unknown. To define more clearly the possiblel role of ET-1 following SCI, we investigated the effect of ET-1 on the contraction, calcium transients and L-type calcium current (ICa,L) in the cardiomyocytes of control and SCI rats. Sixteen Sprague-Dawley male rats aged 80-100 days and weighing 250-350 g were randomized into control and SCI groups. Fourteen days following compression injury to the spinal cord, effects of ET-1 on the contraction, calcium transients and ICa,L were studied in the cardiomyocytes of control and SCI rats by the technique of simultaneous measurement of intracellular Ca2+ and contraction and by whole-cell configuration of the patch-clamp technique. In myocytes from control rats, ET-1 significantly increased contraction, the magnitude of Ca2+ transients and the peak amplitude of ICa,L. However, ET-1 had little effect on the amplitude of contraction, calcium transients and ICa,L in myocytes from SCI rats. These results suggest that the positive inotropic effects of ET-1 on control myocardial contraction may be altered in pathological states such as SCI., Y.-F. Guo ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
Calorie restriction (CR) has been shown to decrease reactive oxygen species (ROS) production an d retard aging in a variety of species. It has been proposed that alterations in membrane saturation are central to these ac tions of CR. As a step towards testing this theory, mice were assigned to 4 dietary groups (control and 3 CR groups) and fed AIN-93G diets at 95 % (control) or 60 % (CR) of ad libitum for 8 months. To manipulate membrane composition, the primary dietary fats for the CR groups were soybean oil (also used in the control diet), fish oil or lard. Skeletal muscle mitochondrial lipid composition, proton leak, and H 2 O 2 production were measured. Phospholipid fatty acid composition in CR mice was altered in a manner that reflected the n-3 and n-6 fatty acid profiles of their respective dietary lipid sources. Dietary lipid composition did not alter proton leak kinetics between the CR groups . However, the capacity of mitochondrial complex III to produce ROS was decreased in the CR lard compared to the other CR groups. The results of this study indicate that dietary lipid composition can influence ROS production in muscle mitochondria of CR mice. It remains to be determined if lard or other dietary oils can maximize the CR- induced decreases in ROS production., Y. Chen ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy