Kurstjens N P, Heithier H, Cantrill R C, Hahn M, Boege F
Department of Physiological Chemistry, University of Würzburg Medical School, F.R.G.
Biochem Biophys Res Commun. 1990 Mar 30;167(3):1162-9. doi: 10.1016/0006-291x(90)90645-4.
Glucagon and prostaglandin E1 stimulate adenylate cyclase in Madin-Darby canine kidney cells with an approximate EC50 of 310(-8) and 110(-7) M respectively. The rise in cAMP is accompanied by a transient rise in intracellular Ca++ measured with the fluorescent calcium indicator Indo-1. A comparable increase in intracellular Ca2+ without a rise in cAMP occurs with the cholinergic agonist carbamylcholine. Stimulation of adenylate cyclase by the beta-adrenergic agonist isoproterenol or directly by forskolin has no effect on intracellular Ca++. By all criteria studied the rise in intracellular Ca++ and the increase in cAMP are independent from each other.
