AJP - Endocrinology and Metabolism, Vol 256, Issue 1 E64-E67, Copyright © 1989 by American Physiological Society
Effects of thyroid status on atrial natriuretic peptide release from isolated rat atria
N. L. Wong, D. Huang, N. S. Guo, E. F. Wong and D. C. Hu
Department of Medicine, Health Sciences Centre Hospital, University of British Columbia, Vancouver, Canada.
The effect of thyroid hormone on circulating levels of atrial natriuretic
peptide (ANP) was studied in experimental hyperthyroid and hypothyroid
rats. Plasma ANP was 102 +/- 5 pg/ml in euthyroid rats, 82 +/- 4 pg/ml in
hypothyroid rats, and 138 +/- 11 pg/ml in hyperthyroid rats. We have also
measured immunoreactive ANP in the atria of euthyroid, hypothyroid, and
hyperthyroid rats. ANP content and concentration in the atria were lower
(546 +/- 32 pg/mg tissue) in hyperthyroid rats than in hypothyroid rats
(802 +/- 74 pg/mg tissue). Right atrium from euthyroid, hypothyroid, and
hyperthyroid rats was superfused with a modified Langendorff preparation.
Spontaneous release of ANP was significantly higher from the hyperthyroid
rats (20 +/- 2 pg.min-1.mg-1) than from the hypothyroid rats (5.6 +/- 0.5
pg.min-1.mg-1). ANP release from the euthyroid rats was 9.3 +/- 1.2
pg.min-1.mg-1. These results indicate hyperthyroidism causes an increase in
ANP secretion and a decreased release occurs during hypothyroidism.
