title: Age-related changes in adenosine metabolic enzymes in sleep/wake regulatory areas of the brain.
abstract: The impact of age on the enzymatic activities of adenosine metabolic enzymes, i.e., adenosine deaminase, adenosine kinase, cytosolic- and ecto-5'-nucleotidase have been assessed in the brain sleep/wake regulatory areas of young, intermediate and old rats (2, 12 and 24 months, respectively). There were significant spatial differences in the distribution of enzymes of adenosine metabolism in the brain. Age did not impact on the enzymatic activity of adenosine deaminase. Adenosine kinase activity increased significantly in the cerebral cortex of old animals. However, there were no differences in the activity of adenosine kinase between young and intermediate aged rats. The largest age-related changes were in the activity of cytosolic- and ecto-5'-nucleotidase and there was a significant age-related increase in the activity of these enzymes in the sleep/wake regulatory areas. In addition, the activity of cytosolic- and ecto-5'-nucleotidase increased in the cerebral cortex of old and intermediate age rats when compared to young animals. An increase in the enzymatic activities in the cerebral cortex of adenosine kinase and 5'-nucleotideases was accompanied by an increase in the level of their mRNA. An increase in the activity of 5'-nucleotideases with age likely leads to an increase in adenosine levels in the brain.
authors.affiliation: Center for Sleep and Respiratory Neurobiology, University of Pennsylvania School of Medicine, 991 Maloney Building, 3600 Spruce Street, Philadelphia, PA 19104-4283, USA. mirekmm@mail.med.upenn.edu
authors.forename: Miroslaw
authors.initials: M
authors.lastname: Mackiewicz
authors.forename: Elena V
authors.initials: EV
authors.lastname: Nikonova
authors.forename: John E
authors.initials: JE
authors.lastname: Zimmermann
authors.forename: Micah A
authors.initials: MA
authors.lastname: Romer
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Cater
authors.forename: Raymond J
authors.initials: RJ
authors.lastname: Galante
authors.forename: Allan I
authors.initials: AI
authors.lastname: Pack
mesh_terms: D015720:5'-Nucleotidase / Q000378:metabolism; D000241:Adenosine / Q000378:metabolism*; D000243:Adenosine Deaminase / Q000235:genetics / Q000378:metabolism; D000248:Adenosine Kinase / Q000378:metabolism; D000375:Aging / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000201:enzymology*; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D011916:Rats, Inbred F344; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D012890:Sleep / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology*
chemical_list: D012333:RNA, Messenger; D000248:Adenosine Kinase; D015720:5'-Nucleotidase; D000243:Adenosine Deaminase; D000241:Adenosine