adenosine , atp , beta , gamma-methylene atp ( appcp ) and 2-chloroadenosine produced negative inotropic and chronotropic effects on the dogfish atrium , which were antagonized by 8-phenyltheophylline , a p1- purinoceptor antagonist . alpha-beta-methylene atp ( apcpp ) , which is resistant to degradation , did not produce a similar inhibitory response in the dogfish atrium .
C0001443
adenosine
C0000275
2-chloroadenosine