24-HOUR TEMPORAL PATTERN OF NTPDase AND 5′-NUCLEOTIDASE ENZYMES IN RAT BLOOD SERUM

Abstract

Circadian rhythms represent an important mechanism to prepare the organism for environmental variations. ATP, ADP, AMP, and adenosine can act as extracellular messengers in a range of biological processes and are metabolized by a number of enzymes, including NTPDases and 5′-nucleotidase. In the present study the authors report that ATPase and ADPase activities present 24-h temporal variations that peak during dark (activity) span. These findings suggest that this enzymatic temporal pattern in blood serum might be important for the normal physiology and function of the organism through the maintenance of extracellular nucleotides at physiological levels. (Author correspondence: [email protected])

Keywords:

• Adenine nucleotides
• NTPDase
• 5′-Nucleotidase
• Nucleotide hydrolysis
• Rats
• Temporal pattern

ACKNOWLEDGMENTS

This work received financial support from Brazilian funding agencies: Graduate Research Group (GPPG) at Hospital de Clínicas de Porto Alegre (Dr. I. L. S. Torres, grant no. 08-150), CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico), and CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior).