Species variations in drug metabolism : investigations on the liver microsomal hydroxylation of tryptamine and related compounds

Abstract

Various tryptamines and indoles were incubated with microsomal preparations obtained from different animal species. The variation of liver microsomal indole 6-hydroxylase activity in different animals exemplifies the species dependence of the drug metabolising enzymes. Age and sex are also factors which have to be considered in studies on drug hydroxylations. Since these species variations render the extrapolation of data from animal to man difficult, a partial but direct approach would involve the use of human liver tissue for the investigations ‘in vitro’ which are necessary in the preliminary stages of the development of new drugs.