Relationship between pD2 and pA2 of neuroleptics

The differences in the pD2/pA2 ratio of nine tested neuroleptics were found to vary between 0.92 and 1.11. This result confirms the hypothesis that pD2 (as determined from the inhibition of spontaneous locomotor activity) and pA2 (as determined from the shift of apomorphine dose response curve induced by a fixed dose of the neuroleptic) should not differ markedly and is discussed as differences in receptor specifities on the basis of the concept of multiple binding sites fo neuroleptics in the brain.