Elisa Bizzoco, Maria-Giuliana Vannucchi, Maria-Simonetta Faussone-Pellegrini
Department of Anatomy, Histology and Forensic Medicine, Section of Histology, University of Florence, Viale G. Pieraccini, 6, 50134 Florence, Italy.
Experimental neurology 2007 MarIn neurodegenerative diseases, an increased number of neuronal nitric oxide synthase (nNOS)-positive neurons was reported, but nothing is known on which are the neurons induced to express nNOS. Argininosuccinate synthetase (ASS), argininosuccinate lyase (ASL) and nNOS act in the L-arginine-NO-L-citrulline cycle permitting a correct NO production. In the brain, nNOS-positive neurons co-expressing ASS were known, while those co-expressing ASL were not demonstrated. We investigated by immunohistochemistry the presence of these types of neurons in the rat striatum to verify whether there was a correlation between their changes due to neurotoxic insults and animal survival. Transient ischemia, a neurodegenerative insult model, was induced in rat brain by 2 h of middle cerebral artery occlusion. The striatum, the core of ischemia, was examined at 24, 72 and 144 h after reperfusion and compared with that of rats in normal condition. ASS, ASL and nNOS-positive neurons, some of the latter also expressing ASS and ASL, were present both in normal and ischemic conditions. At 24 h after reperfusion, the number of the nNOS-positive neurons and the percentage of those co-expressing ASS and ASL were significantly increased in the animals with a longer survival and at 144 h after ischemia there was an almost complete restore of the number and/or percentage of these neurons. We hypothesize that the neurons induced to express nNOS were the ASS- and ASL-positive ones and that the neurons co-expressing nNOS, ASS and ASL, since having the enzymes necessary to maintain a correct NO production, might protect from neurotoxic insults.
Elisa Bizzoco, Maria-Giuliana Vannucchi, Maria-Simonetta Faussone-Pellegrini. Transient ischemia increases neuronal nitric oxide synthase, argininosuccinate synthetase and argininosuccinate lyase co-expression in rat striatal neurons. Experimental neurology. 2007 Mar;204(1):252-9
PMID: 17198704
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