Effects of thyroid status on atrial natriuretic peptide release from isolated rat atria.
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.
Wong
N L
NL
Department of Medicine, Health Sciences Centre Hospital, University of British Columbia, Vancouver, Canada.
Huang
D
D
Guo
N S
NS
Wong
E F
EF
Hu
D C
DC
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D006325:Heart Atria / Q000378:metabolism; D006980:Hyperthyroidism / Q000139:chemically induced / Q000378:metabolism*; D007037:Hypothyroidism / Q000139:chemically induced / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D008713:Methimazole; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013974:Thyroxine
D008713:Methimazole; D009320:Atrial Natriuretic Factor; D013974:Thyroxine