Impaired Inhibitory Function of Presynaptic A(1)-Adenosine Receptors in SHR Mesenteric Arteries

• Type: Article in International Scientific Journal
• Date: 2013

Authors

Carolina Rocha Pereira (Author) Other; Silvia M Magdalena Arribas (Author) Other; Paula Fresco (Author) FFUP; Maria C Carmen Gonzalez (Author) Other; Jorge Goncalves (Author) FFUP; Carmen Diniz (Author) FFUP

Journal

Title: Journal of Pharmacological Sciences

Vol. 122

ISSN: 1347-8613

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 8 Citations

Scopus - 10 Citations

Pubmed / Medline

Scientific classification

FOS: Medical and Health sciences > Basic medicine

Other information

Authenticus ID: P-006-AD4

Abstract (EN): In hypertension, vascular reactivity alterations have been attributed to numerous factors, including higher sympathetic innervation/adenosine. This study examined the modulation of adenosine receptors on vascular sympathetic nerves and their putative contribution to higher noradrenaline spillover in hypertension. We assessed adenosine receptors distribution in the adventitia through confocal microscopy, histomorphometry, and their regulatory function on electrically-evoked [H-3]-noradrenaline overflow, using selective agonists/antagonists. We found that: i) A(1)-adenosine receptor agonist (CPA: 100 nM) inhibited tritium overflow to a lower extent in SHR (25% 3%, n=14) compared to WKY (38% 3%, n = 14) mesenteric arteries; ii) A(2A)-adenosine receptor agonist (CGS 21680: 100 nM) induced a slight increase of tritium overflow that was similar in SHR (22% +/- 8%, n = 8) and WKY (24% +/- 5%, n = 8) mesenteric arteries; iii) A(2B)- and A(3)-adenosine receptors did not alter tritium overflow in either strain; iv) all adenosine receptors were present on mesenteric artery sympathetic nerves and/or some adventitial cells of both strains; and v) A(1)-adenosine receptor staining fractional area was lower in SHR than in WKY mesenteric arteries. We conclude that there is an impaired inhibitory function of vascular presynaptic A(1)-adenosine receptors in SHR, likely related to a reduced presence of these receptors on sympathetic innervation, which might lead to higher levels of noradrenaline in the synaptic cleft and contribute to hypertension in this strain.

Language: English

Type (Professor's evaluation): Scientific