Stimulation of release of adrenal catecholamine by adenosine 3':5'-cyclic monophosphate and theophylline in the absence of extracellular Ca 2+ .
Stimulation of catecholamine release was studied in the isolated adrenal of the cat during retrograde perfusion. Theophylline, adenosine 3':5'-cyclic monophosphate (cyclic AMP), and dibutyryl-cyclic AMP stimulated catecholamine release in adrenal chromaffin tissue; adenosine, 2'-AMP, 3'-AMP, and 5'-AMP were ineffective. Addition of theophylline for 5-15 min had no effect on catecholamine release induced by KCl or nicotine, but it significantly increased the responses to cyclic AMP and its dibutyryl derivative. Glands perfused with Ca(2+)-free Locke's solution for 30-180 min rapidly lost their responsiveness to KCl or nicotine. In contrast, exposure to Ca(2+)-free medium for 180 min had no effect on secretory responses to either the cyclic nucleotides, themselves, or to methylxanthine-induced potentiation of cyclic AMP responses. Thus, dibutyryl-cyclic AMP, cyclic AMP, and theophylline do not require extracellular Ca(2+) to release adrenal catecholamines. They may act by translocating intracellular bound Ca(2+) or by a mechanism independent of calcium.
D000241:Adenosine / Q000494:pharmacology; D000249:Adenosine Monophosphate / Q000494:pharmacology; D000311:Adrenal Glands / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D002087:Butyrates / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology*; D002395:Catecholamines / Q000378:metabolism*; D002415:Cats; D000242:Cyclic AMP / Q000494:pharmacology*; D004357:Drug Synergism; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D009538:Nicotine / Q000494:pharmacology; D010477:Perfusion; D011189:Potassium Chloride / Q000494:pharmacology; D013268:Stimulation, Chemical; D013806:Theophylline / Q000494:pharmacology*; D013997:Time Factors; D014970:Xanthines / Q000494:pharmacology
D002087:Butyrates; D002395:Catecholamines; D014970:Xanthines; D000249:Adenosine Monophosphate; D011189:Potassium Chloride; D009538:Nicotine; D013806:Theophylline; D000242:Cyclic AMP; D000241:Adenosine; D002118:Calcium