Murine lymphocytes lack clearly defined receptors for muscarinic and dopaminergic ligands

[3H]Quinuclidinyl benzilate and [3H]spiperone binding to murine lymphocytes is displaceable but differs from binding to brain receptor sites for these ligands: (1) binding to intact lymphocyte preparations was not saturable; (2) disruption of intact lymphocytes was associated with a marked loss of displaceable ligand binding; (3) drugs differentially displace these ligands in lymphocytes compared to brain. Displaceable binding was increased following incubation of lymphocytes under phospholipid methylating conditions; however, marked effects on cell viability and cell recovery make it difficult to interpret these binding changes. If dopaminergic and cholinergic receptors do exist on lymphocytes, their binding characteristics are profoundly different from comparable cns receptors.