Possible Interaction: Adenosine and Adrenergic Beta-Antagonists

“An essentially different interpretation after beta blocker discontinuation was found in two cases (10%).ConclusionA beta blocker withdrawal induces an increase in adenosine MBF.”

“It is for this reason that blockers of membrane transport enhance the plasma adenosine concentration.”

“Besides the established use of beta-blockers there are some beneficial perspectives for myocardial protection by blockade of the Na(+)-H(+)-exchange or by adenosine.”

“Patients taking drugs such as beta blockers or vagolytic agents may need alterations in the dose of adenosine for therapy.”

“The purinoceptor P2 blockers , suramin and pyridoxal-phosphate-6-azophenyl-2',4'-disulphonic acid (PPADS), inhibited the diadenosine polyphophate-induced [Ca2+]i increase, whereas the P2y purinoceptor blocker, reactive blue, had no effect.”

“Segments … on beta-blockers that contracted normally at … increased blood flow with adenosine (0.78 +/- 0.31 to 1.10 +/- 0.70 mL.g-1.min-1; P < .05), as did … became abnormal (0.74 +/- 0.34 to 1.06 +/- 0.82 mL.g-1.min-1; P = NS).”

“By competitive inhibition of the enzyme phosphodiesterase, they prevent the breakdown of cyclic 39,59—AMP adenosine monophosphate ) to 59—AMP and act synergistically with beta-adrenergic agents to increase the intracellular concentration of 39 5 cyclic AMP.”

“The endogenously released adenosine may have additional cardioprotective effect during beta-adrenergic blockade.”

“Glibenclamide-sensitive currents induced by adenosine and CGS-21680 were largely reduced by blockers of the cAMP-dependent protein kinase (Rp-cAMP[S], H-89, protein kinase A inhibitor peptide).”

“It is, therefore, likely that adenosine (and its analogs) and Ca2+ entry blockers have different mechanisms for the relaxation of coronary smooth muscle and that adenosine probably relaxes the vessels through A2 receptor.”