The Biochemical Pharmacology of Atrial Peptides

A schematic overview is presented as a framework for the more com­ prehensive review of the atrial peptide system that follows (Figure 1). An expanded discussion of the specific details and references is detailed in the subsequent section. Briefly, granules located in the atria (but not the ventri­ cles) contain the 126-amino acid prohormone termed atrial natriuretic factor (ANF) , atrial natriuretic peptide (ANP) , cardionatrin or atriopeptin (AP). cDNA probes have been used to characterize the amino acid sequence of a 152-amino acid rat atrial preprohormone. Non-atrial sites of AP synthesis have also been discovered in the central nervous system and the cardiac ventricle, which only expresses AP biosynthesis during fetal and neonatal development and during cardiac hypertrophy. Recently, Flynn and colleagues announced (at the Third International Congress on Biologically Active Atrial Peptides, New York, June 25-26, 1988) the isolation and sequencing from rat atrial extracts of a unique atriopeptin-like peptide termed iso-rANP (rat atrial natriuretic peptide) (Fig-