“…Other enzymes The level of serum ornithine transcarbamylase is raised in pregnancy (Reichard, Wigvist, and Yllener, 1961) and during the first month of oral contraceptive therapy (Brohult and Westgren, 1965). The level of serum leucine aminopeptidase is raised in pregnancy (Green, Tsou, Bressler, and Seligman, 1955).…”