[Relation between levels of atrial natriuretic factor and circulating plasma volume]

The authors investigated in a group of 50 subjects the influence of changes in the volume of circulating plasma on the feedback regulation of plasmatic concentrations of the atrial natriuretic factor (ANF). They proved a fairly close direct correlation between the plasma concentration of ANF and the plasma volume in litres (r = 0.465, p less than 0.01) and when expressed in percent of body weight (r = 0.546, p less than 0.01). The rising concentration of ANF with the patients' age (r = 0.381, p less than 0.01) may be due to actual age conditioned changes or the more frequent incidence of pathological conditions in more advanced age groups, leading to an increase of the ANF plasma level. The results indicate that in addition to pressure changes and distension of the atria in the regulation of the plasma concentration of ANF also changes in the circulating plasma and blood volume participate which thus influence by a feedback mechanism the volume homeostasis.