[The effect of antihistaminic preparations on the binding of labelled mepyramine, ketanserin and quinuclidinyl benzilate in the rat brain].

The effects of some antiallergic drugs on H1-histamine, 5-HT2-serotonin, and M-cholinoreceptors ligand binding in the rat brain were studied in vitro. Dimedrol, dimebon, and phencarol bonded to H1-receptors: IC50 were 76 +/- 10, 153 +/- 15, 320 +/- 60 nM, respectively. Diazoline and dimebon had some affinity for 5-HT2-receptors, its IC50 was 880 +/- 90 nM. Dimedrol, phencarol and diazoline were found to be active against M-cholinoceptors, but when given in the maximal concentration (10 microM) it acted nonspecifically. In contrast to the other drugs, bicarphen had no effects on the binding of [3H]-mepyramine, [3H]-ketanserine, and [3H]-quinuclidinyl benzylate in the rat brain.