Receptor pharmacology. Its use in neuroleptic research

Dopamine D-1 and D-2 receptors can be labelled selectively by using 3H-SCH 23390 and 3H-Spiperone as ligands, respectively. Neuroleptics are divided into different groups according to their affinity for D-1 and D-2 receptors. Thioxanthenes have comparable affinities for D-1 and D-2 receptors. Phenothiazines have higher affinity for D-2 than for D-1 receptors. Butyrophenones, diphenylbutylpiperidines and substituted benzamides are almost selective inhibitors of D-2 receptors. The affinity of neuroleptics for several other receptor types is mentioned. The use of the receptor binding technique in diseased schizophrenics is discussed. In vivo receptor binding in vitro and ex vivo receptor autoradiography and PET scanning are discussed as alternative methods to evaluate neuroleptics, clinical outcome and treatment strategies.