Transient ischemia increases neuronal nitric oxide synthase, argininosuccinate synthetase and argininosuccinate lyase co-expression in rat striatal neurons.

Abstract

In 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.

• Authors: Elisa Bizzoco, Maria-Giuliana Vannucchi, Maria-Simonetta Faussone-Pellegrini
• Journal: Experimental neurology (Exp Neurol) Vol. 204 Issue 1 Pg. 252-9 (Mar 2007) ISSN: 0014-4886 [Print] United States
• PMID: 17198704 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Nitric Oxide Synthase Type I
• Argininosuccinate Lyase
• Argininosuccinate Synthase

Topics

• Animals
• Argininosuccinate Lyase (metabolism)
• Argininosuccinate Synthase (metabolism)
• Arterial Occlusive Diseases (complications)
• Cerebral Infarction (pathology)
• Corpus Striatum (enzymology)
• Ischemic Attack, Transient (enzymology, etiology, metabolism, physiopathology)
• Male
• Middle Cerebral Artery
• Nervous System (physiopathology)
• Neurons (enzymology)
• Nitric Oxide Synthase Type I (metabolism)
• Rats
• Rats, Wistar
• Reperfusion Injury (enzymology)
• Time Factors