Scavenging of nitric oxide by an antagonist of adenosine receptors

• Type: Article in International Scientific Journal
• Date: 2005

Authors

Sousa, T (Author) Other; Fernandes, E (Author) FFUP; Nunes, C (Author) Other; Laranjinha, J (Author) Other; Carvalho, F (Author) FFUP; Pinho, D (Author) Other; Morato, M (Author) FFUP; Albino Teixeira, A (Author) FMUP

Journal

Title: Journal of Pharmacy and Pharmacology

Vol. 57 No. 3

Pages: 399-404

ISSN: 0022-3573

Publisher: Oxford University Press

Indexing

ISI Web of Knowledge - 10 Citations

Scopus - 10 Citations

Scientific classification

FOS: Medical and Health sciences > Basic medicine

Other information

Authenticus ID: P-000-4JC

DOI: 10.1211/0022357055614

Abstract (EN): Chronic treatment of rats with 1,3-dipropyl-8-sulfophenylxanthine (DPSPX), an antagonist of adenosine receptors, causes hypertension, cardiovascular hypertrophy and hyperplasia and impaired endothelium-dependent vasodilatation. An accelerated degradation of nitric oxide (NO) by scavenging molecules could account for endothelial dysfunction and trophic changes in this hypertension. Our aim was to determine whether DPSPX is a scavenger of NO and if this putative effect is shared by caffeine (1,3,7-trimethylxanthine) and DPCPX (1, 3-dipropyl-8-ciclopentylxanthine), which are also adenosine receptor antagonists but do not induce hypertension in rats. This effect was evaluated by electrochemical and spectrofluorometric assays. Urinary NOx (nitrate + nitrite) excretion was also evaluated in controls and DPSPX-treated rats as a marker for NO bioavailability. DPSPX behaved as a scavenger of NO in a concentration-dependent manner in the electrochemical and spectrofluorometric assays. Caffeine and DPCPX had no scavenging effect. DPSPX-treated rats had decreased excretion of urinary nitrites. We can conclude that: DPSPX has NO scavenging properties that may be involved in the alterations described for DPSPX-hypertensive rats; this NO-scavenging effect is not shared by caffeine and DPCPX, which are also xanthine derivatives and adenosine antagonists.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6