Negative chronotropic action of cyclic AMP on the fetal rat heart in organ culture.
Dibutyryl cyclic AMP and cyclic AMP in a DMSO medium were administered to the fetal rat heart in organ culture. Changes in heart rate were observed. Dibutyryl cyclic AMP in concentrations of 5 X 10(-5) M and 1 X 10(-4) M produced significant negative chronotropism. At a concentration of 1 X 10(-3) M, cyclic AMP in a 3% or 0.5% DMSO medium produced significant negative chronotropism. These data were compared with other studies. The negative chronotropic action of cyclic AMP and its dibutyryl derivative are evidence against the involvement of cyclic AMP in positive cardiac chronotropism.
D000818:Animals; D003994:Bucladesine / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism / Q000494:pharmacology*; D003864:Depression, Chemical; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D005260:Female; D005318:Fetal Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects*; D009206:Myocardium / Q000378:metabolism; D009924:Organ Culture Techniques; D011247:Pregnancy; D051381:Rats
D003994:Bucladesine; D000242:Cyclic AMP; D004121:Dimethyl Sulfoxide