Immunohistochemical characterization of adenosine receptors in rat aorta and tail arteries.
Adenosine plays an important role in the cardiovascular system, activating adenosine A(1), A(2A), A(2B), and A(3) receptors, and regulating blood flow either by acting directly on vascular cells or indirectly because of its effects on the central or peripheral nervous systems. The aim of the present study was to investigate whether the pattern of distribution of adenosine receptor subtypes is different on elastic and muscular, using abdominal aorta and tail arteries as models. Immunohistochemistry using anti-A(1), anti-A(2A), anti-A(2B), and anti-A(3) receptor antibodies was performed on perfused-fixed/paraffin-embedded arteries from Wistar rats. 3,3'-Diaminobenzidine tetrahydrochloride (DAB; activated by hydrogen peroxide) staining revealed significant differences in the abundance of A(1), A(2A), and A(3) receptors between abdominal aorta and tail artery and allowed the identification of distinct distribution patterns for A(1), A(2A), A(2B), and A(3) receptors in the tunica adventitia, media, and intima of muscular and elastic arteries. Data are compatible with several previous functional reports supporting that different adenosine receptor subtype expression and/or their distribution in the vessel wall may influence their respective contribution to the control of blood flow.
Serviço de Farmacologia, REQUIMTE/FARMA, Faculdade de Farmácia, Universidade do Porto, Rua Aníbal Cunha, 164, P 4050-047 Porto, Portugal.
Sandra
S
Leal
Carlos
C
Sá
Jorge
J
Gonçalves
Paula
P
Fresco
Carmen
C
Diniz
D000818:Animals; D001158:Arteries / Q000033:anatomy & histology*; D001699:Biometry; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D043682:Receptor, Adenosine A1 / Q000032:analysis*; D043705:Receptor, Adenosine A2A / Q000032:analysis*; D043704:Receptor, Adenosine A2B / Q000032:analysis*; D043684:Receptor, Adenosine A3 / Q000032:analysis*; D013194:Staining and Labeling / Q000379:methods; D013623:Tail; D017539:Tunica Intima / Q000033:anatomy & histology; D017540:Tunica Media / Q000033:anatomy & histology
D043682:Receptor, Adenosine A1; D043705:Receptor, Adenosine A2A; D043704:Receptor, Adenosine A2B; D043684:Receptor, Adenosine A3