Neurochemical research
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Neurochemical research · Jun 2009
Delayed treatment with carboxy-PTIO permits a 4-h therapeutic window of opportunity and prevents against ischemia-induced energy depletion following permanent focal cerebral ischemia in mice.
We examined whether a nitric oxide scavenger, 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-imidazoline-L: -oxyl-3-oxide (carboxy-PTIO), could offer neuroprotective actions and improve cerebral energy metabolism in a model of stroke. Sixty C57BL/10J mice were given either carboxy-PTIO (0.3-1.2 mg/kg) or vehicle intraperitoneally, 0.5 h after permanent middle cerebral artery occlusion, to evaluate the dose-response effects. An additional 70 animals received carboxy-PTIO (0.6 mg/kg) or vehicle, 2-6 h post-ischemia, for establishing the therapeutic window. ⋯ Four hour post-ischemia, ATP depleted in the ischemic hemisphere (P < 0.05). Administration with carboxy-PTIO not only improved the recovery of ATP in the ischemic hemisphere (P < 0.05), but also enhanced adenosine content across the ischemic and non-ischemic hemispheres (P < 0.05). The neuroprotection of carboxy-PTIO may be partly attributed to the beneficial effects of improving cerebral energy metabolism.
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Neurochemical research · Jun 2009
ReviewZebrafish Rohon-Beard neuron development: cdk5 in the midst.
Cyclin-dependent kinase 5 (cdk5) is a proline-directed serine/threonine kinase that is activated mostly by association with its activators, p35 and p39. Initially projected as a neuron-specific kinase, cdk5 is expressed ubiquitously and its kinase activity solely depends on the presence of its activators, which are also found in some non-neuronal tissues. As a multifunctional protein, cdk5 has been linked to axonogenesis, cell migration, exocytosis, neuronal differentiation and apoptosis. ⋯ One of the functions that we have followed for the cdk5 ortholog in zebrafish in vivo is its effect on the Rohon-Beard (RB) neurons. RB neurons are the primary sensory spinal neurons that die during the first two days of zebrafish development eventually to be replaced by the dorsal root ganglia (DRG). Based on ours studies and others', here we discuss possible mechanisms that may be involved in cdk5's role in RB neuron development and survival.