The participation of adenosine receptors in the adenosine 5'-triphosphate-induced relaxation in the isolated rabbit corpus cavernosum penis.
OBJECTIVE
To investigate the participation of adenosine receptors in the adenosine 5'-triphosphate (ATP)-induced relaxation in the corpus cavernosum penis (CCP) of rabbits.


METHODS
The ATP-induced relaxation was assessed on the noradrenaline precontracted CCP of rabbits in the presence and absence of 8-(3-chlorostyryl)caffeine (CSC); an adenosine A(2A) receptor antagonist; alloxazine and MRS1754; adenosine A(2B) receptor antagonists; and ARL67156, an inhibitor of ecto-nucleoside triphosphate diphosphohydrolases.


RESULTS
Adenosine and ATP relaxed the noradrenaline precontracted CCP of rabbits in a concentration-dependent manner. The adenosine- and ATP-induced relaxations were suppressed by alloxazine and MRS1754, but not by 8-(3-chlorostyryl)caffeine. ARL67156 potentiated the ATP-induced relaxation but not the adenosine-induced one. MRS1754 suppressed the ATP-induced relaxation potentiated by ARL67156.


CONCLUSIONS
The above results suggest that, in the CCP of rabbits, the adenosine receptor mediating adenosine-induced relaxation is of the A(2B) receptor and the ATP directly causes relaxation through the A(2B) receptor on the CCP.
Kataoka
Kazuyoshi
K
Department of Urology, Faculty of Medicine, Toho University, Omorinishi, Tokyo, Japan.
Furukawa
Katsuo
K
Nagao
Kohichi
K
Ishii
Nobuhisa
N
Tsuru
Hiromichi
H
D000081:Acetamides / Q000494:pharmacology; D000241:Adenosine / Q000494:pharmacology; D058908:Adenosine A2 Receptor Agonists; D058917:Adenosine A2 Receptor Antagonists; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology*; D000818:Animals; D002110:Caffeine / Q000031:analogs & derivatives / Q000494:pharmacology; D005415:Flavins / Q000494:pharmacology; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects / Q000502:physiology; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D010410:Penile Erection / Q000187:drug effects* / Q000502:physiology; D010413:Penis / Q000187:drug effects* / Q000502:physiology; D058906:Purinergic P1 Receptor Agonists; D058915:Purinergic P1 Receptor Antagonists; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D011687:Purines / Q000494:pharmacology; D011817:Rabbits; D043705:Receptor, Adenosine A2A / Q000378:metabolism; D043704:Receptor, Adenosine A2B / Q000378:metabolism; D018047:Receptors, Purinergic P1 / Q000378:metabolism*; D018048:Receptors, Purinergic P2 / Q000378:metabolism
C092431:6-N,N-diethyl-beta,gamma-dibromomethylene-D-ATP; D000081:Acetamides; D058908:Adenosine A2 Receptor Agonists; D058917:Adenosine A2 Receptor Antagonists; D005415:Flavins; C423842:N-(4-cyanophenyl)-2-(4-(2,3,6,7-tetrahydro-2,6-dioxo-1,3-dipropyl-1H-purin-8-yl)-phenoxy)acetamide; D058906:Purinergic P1 Receptor Agonists; D058915:Purinergic P1 Receptor Antagonists; D058910:Purinergic P2 Receptor Agonists; D058919:Purinergic P2 Receptor Antagonists; D011687:Purines; D043705:Receptor, Adenosine A2A; D043704:Receptor, Adenosine A2B; D018047:Receptors, Purinergic P1; D018048:Receptors, Purinergic P2; C081320:8-(3-chlorostyryl)caffeine; D002110:Caffeine; C008173:isoalloxazine; D000255:Adenosine Triphosphate; D000241:Adenosine