ODC1 and cardiac hypertrophy: Nevertheless, since the ornithine decarboxylase (ODC), as a rate-limiting enzyme in polyamine biosynthesis, included in cardiac hypertrophy induced by a β-adrenergic stimulation, is suppressed with both captopril and AT1 receptor antagonist [127,128], these results indicate that RAS may be involved in the induction of myocardial hypertrophy.