The Quantum Nature of Drug-Receptor Interactions: Deuteration Changes Binding Affinities for Histamine Receptor Ligands
Fig 3
Inhibition of specific binding of 3H- tiotidine in cultured astrocytes with histamine, 2- and 4-methylhistamine; 2-MeHi and 4-MeHi, respectively.
Deuteration significantly (p < 0.0001) decreased the pIC50 of 2-methylhistamine (8.38 ± 0.13 (control) to 6.85 ± 0.16 (D2O)), whereas it significantly (p < 0.05) increased the pIC50 of histamine (7.25 ± 0.11 (control) to 7.80 ± 0.16 (D2O)) and marginally increased the pIC50 value of 4-methylhistamine from 7.31 ± 0.28 (control) to 7.67 ± 0.13 (D2O).