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.
Department of Urology, Faculty of Medicine, Toho University, Omorinishi, Tokyo, Japan.
Kazuyoshi
K
Kataoka
Katsuo
K
Furukawa
Kohichi
K
Nagao
Nobuhisa
N
Ishii
Hiromichi
H
Tsuru
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