AJP - Regulatory, Integrative and Comparative Physiology, Vol 249, Issue 5 595-R602, Copyright © 1985 by American Physiological Society
Effect of pulmonary and renal circulations on activity of atrial natriuretic factor
E. O. Weselcouch, W. R. Humphrey and J. W. Aiken
The effect of passage through the pulmonary and renal circulation on the
activity of extracted and synthetic atrial natriuretic factors was
determined by monitoring the amount of the vascular relaxing activity
surviving passage through the organ. When crude atrial extract was infused
through isolated perfused lungs of the guinea pig, approximately 75% of its
activity survived. The activity of a 23-amino acid synthetic atrial peptide
was decreased 21% on passage through these lungs, but this loss of activity
was not significantly different from the crude extract. Analogous
experiments in vivo showed that passage through the pulmonary circulation
of the dog did not alter the activity of either the crude atrial extract or
of synthetic atrial peptide. In contrast to the lack of effect of the
pulmonary circulation, approximately 80% of the activity of crude atrial
extract and synthetic atrial peptide was removed by the isolated perfused
kidney of the rabbit, and in vivo the dog kidney removed approximately 80%
of the activity of both these atrial substances. By surviving transit
through the pulmonary circulation, these materials exhibit a necessary
property of a circulating hormone stored in the right atrium, and the fact
that the renal circulation extracts most of these materials is consistent
with the kidney being a target organ of this putative hormone.
