Possible Interaction: Caffeine and Isoproterenol

“Application of 100 nmol/L isoproterenol and 0.5 mmol/L caffeine led to triggered arrhythmia in isolated cardiac muscles from non‐failing and end‐stage failing hearts.”

“More importantly, clinically relevant concentrations of caffeine (10 to 50 micro M) potentiated the effects of desmopressin (DDAVP), prostaglandin E(2) (PGE(2)), and isoproterenol to increase cAMP levels in both ADPKD and HKC cells.”

“Sorcin KO mice presented ventricular arrhythmia and sudden death when challenged by acute stress induced by isoproterenol plus caffeine.”

“The responses of hearts isolated from caffeine group to the three doses of isoproterenol infusion also showed a significantly higher dT/dtmax with shorter TPT and half relaxation time (1/2 RT) compared to controls.”

“These myocytes, when exposed to isoproterenol and caffeine , displayed disturbances in their rhythmic Ca2+ oscillations and membrane potential, and delayed afterdepolarizations.”

“ Isoproterenol in the presence of caffeine (100 to 300 &mgr;mol/L) induced epicardial VT in 9 of 16 wedge preparations.”

“Ca2+ release after caffeine addition in untreated females was 376 +/- 27 nM and increased to 503 +/- 49 nM with isoproterenol , significantly less than in male myocytes treated with isoproterenol (P < 0.05).”

“Administration of 400μM caffeine or 200μM (+) propranolol brought down the isoproterenol‐induced elevation in the cell division rate to control levels.”

“ Isoproterenol , forskolin, and DBcAMP enhanced this [Ca2+]i response to caffeine in control myocytes more markedly than in diabetic myocytes.”

“Rapid initial tension development observed under a variety of situations (short cycle lengths, stimulation rates of 0.25 Hz plus isoproterenol , decreased external Na+ concentration) was markedly depressed by 0.01-1 microM ryanodine and by caffeine , whereas local anesthetics had little effect.”