title: Age-related changes in nitric oxide synthase and arginase in the rat prefrontal cortex.
abstract: Increasing evidence suggests that nitric oxide (NO), generated by nitric oxide synthase (NOS) from l-arginine, plays an important role in the ageing process. The present study, for the first time, investigates age-related changes in NOS and arginase, an enzyme that shares a common substrate with NOS, in the prefrontal cortex of rats assessed with and without prior behavioural testing. A significant increase in total NOS activity was found in the prefrontal cortex in aged (24-month-old) as compared with young (4-month-old) rats. Western blotting revealed that there were no significant differences between young and aged rats in neuronal NOS (nNOS) and endothelial NOS (eNOS) protein expression. Inducible isoform of NOS (iNOS), in terms of activity and protein expression, was not detected in either group. Total arginase activity and arginase I and II protein expression did not differ between the young and aged groups. The present findings support the contribution of NOS/NO to ageing but question the importance of iNOS in the normal ageing process.
authors.affiliation: Department of Pharmacology and Toxicology, School of Medical Sciences, Dunedin, New Zealand. ping.liu@stonebow.otago.ac.nz
authors.forename: P
authors.initials: P
authors.lastname: Liu
authors.forename: P F
authors.initials: PF
authors.lastname: Smith
authors.forename: I
authors.initials: I
authors.lastname: Appleton
authors.forename: C L
authors.initials: CL
authors.lastname: Darlington
authors.forename: D K
authors.initials: DK
authors.lastname: Bilkey
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D001119:Arginase / Q000378:metabolism*; D008297:Male; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D017397:Prefrontal Cortex / Q000201:enzymology*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D019001:Nitric Oxide Synthase; D001119:Arginase