| Literature DB >> 17992570 |
Nadezda Nedeljkovic1, Ivana Bjelobaba, Irena Lavrnja, Danijela Stojkov, Sanja Pekovic, Ljubisav Rakic, Mirjana Stojiljkovic.
Abstract
During a variety of insults to the brain adenine nucleotides are released in large quantities from damaged cells, triggering multiple cellular responses to injury. Here, we evaluated changes in extracellular ATP, ADP and AMP hydrolysis at different times (0-24 hours) after unilateral cortical stab injury (CSI) in adult rats. Results demonstrated that 24 hours following CSI, ATP and ADP hydrolyzing activities were not significantly altered in injured cortex. Based on calculated V (ATP)/V (ADP) ratio it was concluded that ATP/ADP hydrolysis was primarily catalyzed by NTPDase1 enzyme form. In contrast, AMP hydrolysis, catalyzed by 5'-nucleotidase, was significantly reduced at least 4 hours following CSI. Kinetic analysis and Lineweaver-Burk transformation of the enzyme velocities obtained over the range of AMP concentrations (0.05-1.50 mM) revealed that inhibition of 5'-nucleotidase activity after CSI was of the uncompetitive type. Taken together our data suggest that injured tissue has reduced potential for extracellular metabolism of adenine nucleotides in early stages after CSI.Entities:
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Year: 2007 PMID： 17992570 DOI： 10.1007/s11064-007-9529-0
Source DB: PubMed Journal: Neurochem Res ISSN： 0364-3190 Impact factor: 3.996