Deans' stroke musings: Development of a Reactive Oxygen Species-Sensitive Nitric Oxide Synthase Inhibitor for the Treatment of Ischemic Stroke

Nitric Oxide is known to be protective in ischemic stroke. Yet we still don't have a stroke protocol on it. Billions of neurons die every year because of the fucking laziness and stupidity of the stroke medical professionals. 86 posts on nitric oxide back to March 2011 so your doctor can inform you when and how much you should be getting post stroke. Don't do this on your own, you wouldn't want to get recovered better without your doctors help, would you?
https://www.sciencedirect.com/science/article/pii/S0891584917312790

https://doi.org/10.1016/j.freeradbiomed.2017.12.027

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Highlights

•: The nitrone 5 decomposes after reaction with ROS to the NOS inhibitor (6).
•: 5 showed neuroprotection through in vitro and in vivo models of ischemia.
•: 6 but not 5 exhibited a dose-dependent decrease in microglial NO production.
•: 6 is formed preferentially under oxidative stress conditions in vitro and in vivo.

Abstract

Ischemic stroke is caused by a blockage of cerebral blood flow resulting in neuronal and glial hypoxia leading to inflammatory and reactive oxygen species (ROS)-mediated cell death. Nitric oxide (NO) formed by NO synthase (NOS) is known to be protective in ischemic stroke, however NOS has been shown to ‘uncouple’ under oxidative conditions to instead produce ROS. Nitrones are antioxidant molecules that are shown to trap ROS to then decompose and release NO. In this study, the nitrone 5was designed such that its decomposition product is a NOS inhibitor, 6, effectively leading to NOS inhibition specifically at the site of ROS production. The ability of 5to spin-trap radicals and decompose to 6 was observed using EPR and LC-MS/MS. The pro-drug concept was tested in vitro by measuring cell viability and 6 formation in SH-SY5Y cells subjected to oxygen glucose deprivation (OGD). 5 was found to be more efficacious and more potent than PBN, and was able to increase phospho-Akt while reducing nitrotyrosine and cleaved caspase-3 levels. 6 treatment, but not 5, was found to decrease NO production in LPS-stimulated microglia. Doppler flowmetry on anesthetized mice showed an increased cerebral blood flow upon intravenous administration of 1 mg/kg 5, but a return to baseline upon administration of 10 mg/kg, likely due to its dual nature of antioxidant/NO-donor and NOS-inhibition. Mice treated with 5 after permanent ischemia exhibited a >30% reduction in infarct volume, and higher formation 6 in ischemic tissue resulting in region specific effects limited to the infarct area.