Here we induced flow-mediated dilatation of the brachial artery in response to ischemia in 141 non-diabetic patients with stage 3-4 chronic kidney disease who had no history of smoking, cardiovascular events or use of erythropoietin-based agents. Patients
with hemoglobin concentrations above the cohort median of 11.6 g/dl were found to have significant reductions in flow-mediated dilatation compared to those below the median. This inverse relationship remained significant after adjustment for potential confounders, including insulin sensitivity, glomerular filtration rate, proteinuria, body mass index, serum urate, etiology of underlying renal disease, treatment with anti-hypertensive drugs, and traditional Framingham risk factors. Given that hemoglobin can act as an important nitric oxide carrier and buffer, our studies suggest that the mechanism by which hemoglobin influences the endothelium-dependent selleck chemical microcirculation requires its nitrosylation; however, more direct studies need to be performed. Kidney International (2009) 75, 1316-1321; doi:10.1038/ki.2009.63; published online 4 March 2009″
“Stressful experiences, especially when prolonged and severe are associated with psychopathology and impaired neuronal plasticity. Among other effects on the brain, stress has been shown to negatively regulate hippocampal neurogenesis,
and this effect is considered to be exerted via glucocorticoids. Here, we BMS-777607 price sought to determine the temporal dynamics of changes in hippocampal neurogenesis after acute and chronic exposure to foot-shock stress. Rats subjected to a foot-shock procedure showed strong activation
PF299804 mw of the hypothalamic-pituitary-adrenal (HPA) axis, even after exposure to daily stress for 3 weeks. Despite a robust release of corticosterone, acute foot-shock stress did not affect the rate of hippocampal cell proliferation. In contrast, exposure to foot-shock stress daily for 3 weeks led to reduced cell proliferation 2 hours after the stress procedure. Interestingly, this stress-induced effect did not persist and was no longer detected 24 hours later. Also, while chronic foot-shock stress had no impact on survival of hippocampal cells that were born before the stress procedure, it led to a decreased number of doublecortin-positive granule neurons that were born during the chronic stress period. Thus, whereas a strong activation of the HPA axis during acute foot-shock stress is not sufficient to reduce hippocampal cell proliferation, repeated exposure to stressful stimuli for prolonged period of time ultimately results in dysregulated neurogenesis. In sum, this study supports the notion that chronic stress may lead to cumulative changes in the brain that are not seen after acute stress. Such changes may indicate compromised brain plasticity and increased vulnerability to neuropathology. (C) 2009 IBRO. Published by Elsevier Ltd. All rights reserved.