[Fluorescence-analytical studies of the reaction of several psychoactive drugs with membrane structures of the CNS]

The use of 1-anilino-8-naphthalene sulfonate (ANS) as an indicator of membrane conformational perturbations induced by psychoactive drugs was tested with regard to its specificity considering both chemical structure (phenothiazine, butyrophenone, phenylalkylhydrazine) and pharmacological activity (major transquilizers, antidepressants, antihistamines), on the one hand, and brain region (cortex, striatum, hippocampus) and subcellular structure of membranes (mitochondria, microsomes, synaptosomes), on the other. Not only a weak strengthening of ANS affinity to membrane constituents by chlorpromazine and promethazine (haloperidol and phenelzine were without effect), but also the alteration of membrane structure in such a way as to create additional ANS binding sites by chlorpromazine and to a smaller degree also by promethazine and haloperidol (phenelzine was without effect) resulting in a manifold increase in fluorescence indicated any relation to functional characteristics of biological material or properties of drugs. Apparent dissociation constants and membrane ANS binding sizes are reported.