Possible modulation of release of atrial natriuretic factor by endothelium-derived relaxing factor.
The aim of the present study was to investigate the influence of inhibitors of endothelium-dependent relaxing factor on the release of atrial natriuretic factor from isolated rat atria. Electrical stimulation of the tissue produced a frequency-dependent increase in secretion of atriopeptide from basal levels. Saponin (0.3 mg/ml for 45 min) augmented the basal release of the peptide. Methylene blue (10(-5)M), oxyhemoglobin (10(-6)M), or hydroquinone (10(-5)M), agents that inhibit the effects of endothelium-derived relaxing factor by different mechanisms, caused an increase in the basal secretion of atrial natriuretic factor. Blockade of cyclooxygenase with indomethacin (10(-5)M) did not alter the release of atriopeptide, suggesting that it is not controlled by endogenous prostaglandins. These results would be explained if the inhibitors tested were to interfere with a factor released continuously from either endocardial cells or endothelial cells of the atrial blood vessels and having the same nature as endothelium-derived relaxing factor. Such release may exert a tonic negative modulatory influence on the secretion of atrial natriuretic factor.
Sanchez-Ferrer
C F
CF
Department of Physiology and Biophysics, Mayo Clinic, Rochester, Minnesota 55905.
Burnett
J C
JC
Lorenz
R R
RR
Vanhoutte
P M
PM
D000818:Animals; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D004558:Electric Stimulation; D006325:Heart Atria; D006873:Hydroquinones / Q000494:pharmacology; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D008751:Methylene Blue / Q000494:pharmacology; D009206:Myocardium / Q000378:metabolism; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000502:physiology*; D010108:Oxyhemoglobins / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains
D006873:Hydroquinones; D010108:Oxyhemoglobins; D009569:Nitric Oxide; D009320:Atrial Natriuretic Factor; D008751:Methylene Blue; C031927:hydroquinone; D007213:Indomethacin