Changes induced by caffeine, theophylline and theobromine on calcium uptake, respiration and ATP levels in rat-liver mitochondria.
1. The inhibition of calcium uptake and cellular respiration depend on the concentration of the compounds as shown by the concentration-effect curves. 2. The concentrations at which 50% inhibition of the transport of calcium takes place (caffeine 45 mM, theophylline 12 mM, theobromine, 4 mM) do not coincide exactly with those that produce the same effect on cellular respiration (caffeine 60 mM, theophylline 22 mM, theobromine 8 mM). 3. ATP concentrations under different conditions were also determined; a decrease in their value induced by the drugs was observed. No significant differences were observed, however, between the effect produced by the methyl-xanthines. 4. These findings suggest that these compounds are able to affect in some way the maintenance of energy gradients linked to the effects studied.
de la Cruz
M J
MJ
Departamento de Bioquímica, Facultad de Medicina, Universidad Complutense de Madrid, Spain.
Alemany
J
J
Roncero
I
I
Albert
P
P
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D005260:Female; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D013805:Theobromine / Q000494:pharmacology; D013806:Theophylline / Q000494:pharmacology; D014970:Xanthines / Q000494:pharmacology*
D014970:Xanthines; D002110:Caffeine; D000255:Adenosine Triphosphate; D013806:Theophylline; D013805:Theobromine; D002118:Calcium