when the recording electrodes contained the nonhydrolysable derivative of guanosine 5'-triphosphate ( gtp ) , guanosine 5'-o- ( 3-thiotriphosphate , gtp-gamma-s ) , the effects of applied alpha 2-adrenoceptor agonists did not reverse when they were washed from the tissue , implying that gtp hydrolysis is necessary for the termination of agonist action .
C0079469
guanosine 5
C0018353
gtp