Atrial natriuretic factor: The heart as an endocrine organ

Abstract

The growth in understanding about ANF over the last 10 years reflects the pace of modern biological research. Within three years of the initial report that atrial extract contained a natriuretic factor, human ANF was purified, sequenced, and cloned. Atrial dimension is the major determinant of ANF release, ANF has natriuretic and vasodilator effects, and ANF has a definite role in response to an acute increase in intravascular volume. It is not yet clear how important ANF is in the regulation of sodium and water balance and blood pressure under steady state, physiological conditions. Most of our understanding is derived from experimental studies in animal models or from observational studies in adult man. The production of ANF by biotechnology allows interventional studies, however, and further advances may be made if specific antagonists of ANF can be developed. ANF may have therapeutic potential in teh treatment of heart failure, respiratory distress syndrome, acute renal failure, oedema and ascites, systemic and pulmonary hypertension, and asthma. ANF antagonists might prevent hyponatraemia of prematurity and alleviate Bartter's syndrome. ANF is not nephrotoxic and is without many of the side effects of current diuretics and vasodilators but its use is currently limited by the very short half life and the need for intravascular administration.