B, In non-VP–eGFP PVN cells ( n = 21 in saline and 20 in AngII groups), NMDA (100 μ m) significantly increases ROS production in both saline (31.5 ± 4.9% p 0.05 vs saline infusion). A, Representative images of bright-field and VP–eGFP cells (green) and ROS-dependent Eth fluorescence (red) of these cells before and after the application of NMDA from an animal infused with AngII for 14 d. Our results suggest that chronic low-dose AngII may offset the homeostatic control of blood pressure by differentially affecting membrane assembly of NADPH oxidase and ROS production in vasopressin and non-vasopressin neurons located within the PVN.Ĭomparisons of baseline ROS levels and NMDA-triggered ROS production between saline- and AngII-infused PVN cells. Isolated non-VP-eGFP neurons from the PVN of AngII-infused mice also showed an increase in baseline ROS production not seen in VP-eGFP neurons. In contrast, AngII infusion decreased p47(phox) immunolabeling on the plasma membrane (-35.5 ± 16.5% p < 0.05) in vasopressin dendrites. Compared with saline, AngII recipient mice had a significant increase in p47(phox) immunolabeling on endomembranes just beneath the plasmalemmal surface (+42.1 ± 11.3% p < 0.05) in non-vasopressin dendrites. Ultrastructural analysis of the PVN demonstrated p47(phox) immunolabeling in many glial and neuronal profiles, most of which were postsynaptic dendrites. min(-1), s.c.) for 2 weeks, during which they slowly developed hypertension.C57BL/6 mice or vasopressin-enhanced green fluorescent protein (VP-eGFP) mice were infused systemically with saline or AngII (600 ng We addressed this question using ROS imaging and electron microscopic dual labeling for vasopressin and p47(phox), a cytoplasmic NADPH oxidase subunit requiring mobilization to membranes for the initiation of ROS production. This region contains vasopressin and non-vasopressin neurons that are responsive to cardiovascular dysregulation, but it is not known whether ROS is generated by one or both cell types in response to "slow-pressor" infusion of AngII. NADPH oxidase-generated reactive oxygen species (ROS) are highly implicated in the development of angiotensin II (AngII)-dependent hypertension mediated in part through the hypothalamic paraventricular nucleus (PVN).
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