title: Time course of release of atrial natriuretic peptide in the anaesthetized dog.
abstract: In 12 chloralose anaesthetized dogs plasma concentration of immunoreactive atrial natriuretic peptide (IR-ANP) was measured using a radioimmunoassay. Plasma IR-ANP was 74 +/- 4.8 pg/mL (mean +/- SE) and increased by 39 +/- 4.1 pg/mL when left atrial pressure was increased by 10 cm H2O during partial mitral obstruction. Observation of the time course of the changes in IR-ANP during atrial distension showed that IR-ANP was increased within 2 min of atrial distension and declined after atrial distension, with a half-time of 4.5 min. The time course of the changes in IR-ANP was unaffected by vagotomy or administration of atenolol. Maximum electrical stimulation of the right ansa subclavia failed to produce any change in IR-ANP. IR-ANP was higher in coronary sinus plasma than in femoral arterial plasma confirming that the heart was the source of the IR-ANP. The results support the hypothesis that IR-ANP is released from the heart by a direct effect of stretch of the atrial wall rather than by a neural or humoral mechanism involving a reflex from atrial receptors.
mesh_terms: D000818:Animals; D001262:Atenolol / Q000494:pharmacology; D009320:Atrial Natriuretic Factor / Q000097:blood / Q000378:metabolism*; D001794:Blood Pressure; D003331:Coronary Vessels; D004285:Dogs; D005263:Femoral Artery; D006325:Heart Atria; D009206:Myocardium / Q000378:metabolism*; D013564:Sympathetic Nervous System / Q000502:physiology; D014628:Vagotomy
chemical_list: D001262:Atenolol; D009320:Atrial Natriuretic Factor