AJP - Regulatory, Integrative and Comparative Physiology, Vol 253, Issue 5 696-R700, Copyright © 1987 by American Physiological Society
Extracted and nonextracted atrial natriuretic peptide in rabbits during tachycardia
A. J. Rankin, J. R. Ledsome, R. Keeler and N. Wilson
Department of Physiology, University of British Columbia, Vancouver, Canada.
The time course of changes in the plasma concentration of immunoreactive
atrial natriuretic peptide (iANP) accompanying tachycardia was measured in
anesthetized rabbits. In contrast to the hemodynamic changes, which
occurred within the 1st min of tachycardia, the plasma iANP increased
gradually and did not reach significantly elevated levels until 10 min into
the stimulation period. After 20 min of tachycardia iANP was almost 200
pg/ml. Immunoreactive ANP was measured prior to and following extraction.
Although the basal levels of iANP were higher in the unextracted than in
extracted plasma (62 vs. 22 pg/ml), the time course of changes in iANP was
identical in both. The gradual increase in iANP suggests that the release
of iANP in this model may not simply be a consequence of the increase in
atrial pressure.
