The gene for the atrial natriuretic factor is expressed in the aortic arch

The gene for atrial natriuretic factor is expressed within the adventitial cells of the rat aortic arch. Atrial natriuretic factor transcripts, similar in overall size (1100-1200 nucleotides) and 5'-termini to those found in the atria, were identified in the arch. Much lower levels (approximately 10-20%) of these transcripts were present in distal thoracic aorta. Atrial natriuretic factor peptide was localized by immunocytochemistry to the adventitia of the arch in regions thought to harbor the aortic baroreceptors. These data suggest a previously unsuspected role for the peptide in regulating systemic blood pressure through the baroreceptor reflex.