Effects of catecholamines and monovalent cations on adenylate cyclase activity in cultured glial tumor cells

Abstract

1. 1. Adenylate cyclase activity was demonstrated in homogenates of rat glial tumor cells grown in culture. 2. 2. Catecholamines, in an order of potency related to their activity ad β-adrenergic agonists, and fluoride stimulated glial cell adenylate cyclase activity without altering the rate of adenosine 3′,5′-monophosphate breakdown. 3. 3. Lithium chloride (10 mM) enhanced epinephrine stimulated adenylate cyclase activity more than 2-fold while affecting fluoride stimulated levels of adenylate cyclase activity only slightly. 4. 4. Other monovalent cations also potentiated epinephrine stimulated adenylate cyclase activity in the order Li + > Na + > K +. 5. 5. These results strongly suggest that girl cells contribute to levels of adenylate cyclase activity measured in brain tissue. Lithium ions may exert their effects through the molecular processes involved in epinephrine stimulation of adenylate cyclase activity.