Natriuretic factors

Unit recently most attention in the pathogenesis of ascites has focused on antinatriuretic factors. It has now become clear that early in the natural history of the sodium retaining tendency in cirrhosis the antinatriuretic substances are not involved. Rather, whatever the mechanism, natriuretic substances, such as atrial natriurctic factor stimulated by an increase in atrial volume, and renal prostaglandin E excretion, increase to compensate for this. In this way the cirrhotic patient though volume expanded may remain ascites free for many years. Subsequent decompensation leading to systemic circulatory changes, relative arterial underfilling and an increase in antinatriuretics prevent further compensation, resulting in ascites formation.