Abstract
The nature of LSD-induced difference spectra in rat liver microsomes was investigated. The gradual shift from the type I spectrum to the modified type II spectrum with increasing concentration of LSD in hepatic microsomes suggested a composite change of two spectra. The type I component of LSD was obtained by subtracting the spectra in the presence of both the type I compound and LSD from the spectra of LSD alone. The spectral dissociation constant obtained from the spectra of the type I component of LSD was almost exactly equal to the Km value obtained from the disappearance of LSD in the enzymatic transformation.
