Abstract

The oxidative deamination of oral propranolol has been studied in dogs by mass fragmentography. Isopropylamine and hexadeuterated isopropylamine were identified as urinary metabolites of propranolol and hexadeuterated propranolol, respectively. This is the first example of a one-step deamination of an N-isopropylamino compound. Criteria of identity include: two specific fragment ions, their relative intensity and the retention time compared to a reference compound. The specificity provided by stable isotope labeling is demonstrated. Isopropylarnine exerts cardiac as well as peripheral vascular effects.