Solubilized adenosine receptors in the brain: regulation of guanine nucleotides.

Adenosine receptors associated with a reduction of adenylate cyclase and labeled by tritium-labeled cyclohexyladenosine can be solubilized from brain membranes with sodium cholate. Regulation of receptor binding by guanine nucleotides is retained in the soluble state. Influences of cations observed in membrane preparations of adenosine receptors are no longer detected with the solubilized receptors. The apparent retention of a complex of receptors and guanosine triphosphate binding but not cation binding protein in the soluble state may permit a molecular analysis of receptor regulation.