Possible Interaction: Theophylline and Calcium Supplement

“ Theophylline , therefore, may exert adverse effects on the metabolism and urinary excretion of calcium and magnesium in subjects with recurrent asthmatic attacks.”

“From the present results it is suggested that quercetin selectively and verapamil primarily act to block calcium-gate opening resulting from antigen-antibody interaction on the mast cell membrane, while theophylline and disodium cromoglycate selectively inhibit the passage of calcium through open calcium channels.”

“However caffeine and theophylline , which enhance CICR in other systems, blocked IADP induction.”

“It was reported that phosphodiesterase (PDE) inhibitors such as caffeine, theophylline and amrinone accelerate Ca(2+)-induced Ca2+ release (CICR) rate from sarcoplasmic reticulum (SR) in skeletal muscle.”

“ Theophylline (10 mM) releasing calcium from intracellular stores lowered ATP and O2 consumption rate at pH 7.4 but not at pH 6.0 being effective only in calcium-containing medium.”

“Removal of adenosine inhibition by theophylline accelerated ischemic calcium uptake and enhanced electrically evoked calcium uptake in control animals.”

“Atherosperminine (25-100 microM) and theophylline (10-1000 microM) both inhibited the contractile response caused by carbachol, prostaglandin F2 alpha (PGF2 alpha), U46619 (thromboxane A2 analogue), leukotriene C4 (LTC4) and Ca2+ (in the presence of 120 mM KCl) in a concentration-dependent manner.”

“These results suggest that caffeine and theophylline promote the calcium release from sarcoplasmic reticulum and probably the entry of calcium from external medium.”

“The adenosine receptor antagonist, theophylline , led to a marked increase of delta Ca in the synaptic and in the soma layer reflecting an increased activation and enhanced frequency potentiation of pyramidal neurons in the absence of endogenous adenosine action.”

“Higher doses of Ca2+ (200-400 micrograms) produce antinociception in the tail flick and hot plate tests, which is completely blocked by pretreatment with the adenosine receptor antagonists theophylline , 50 micrograms and 8-phenyltheophylline, 3 micrograms.”