A monoclonal anti-imipramine antibody with antidepressant binding properties similar to the muscarinic receptor.

A murine monoclonal antibody raised using imipramine conjugated to bovine serum albumin bound free imipramine with high affinity (KD = 24 nM). The antibody had a binding affinity profile for tricyclic and other uptake-inhibitor type antidepressants which correlated highly with the affinities of the same compounds for the brain acetylcholine muscarinic receptor, but not for plasma-membrane 5-hydroxytryptamine carriers. This antibody was not similar in binding properties to polyclonal antisera produced using the same antigen but was highly similar in binding properties to a monoclonal anti-nortriptyline antibody, ANT3, raised by Marulo et al. (Marulo S, Hoebeke J, Guillet JG, Andre C and Strosberg AD, J Immunol 138: 524-526, 1987) using a different antigen.