Endogenous plasma atrial natriuretic peptide and the control of salt gland function in the Pekin duck.
Polyclonal antibodies raised in a rabbit against avian atrial natriuretic peptide (ANP) were used to investigate the role of endogenous plasma ANP in the control of salt gland function of conscious, saltwater-adapted Pekin ducks. Salt gland secretion was initiated and maintained either by a hypervolemic (290 mosmol/kg NaCl i.v. at 2 ml/min) or hyperosmotic (1,000 mosmol/kg NaCl i.v. at 0.4 ml/min) stimulus. Both experimental conditions caused significant elevations in endogenous plasma ANP concentrations. At steady states of secretion driven by hypervolemia, the administration of ANP antiserum (anti-ANP), which reduced plasma ANP concentrations by 90%, caused an immediate 30% reduction in fluid secretion rate and sodium excretion that lasted for 20-30 min. The activity of salt glands driven by hyperosmolality was not changed by anti-ANP. The results show that the high circulating concentrations of endogenous ANP associated with conditions of sustained volume expansion promote salt gland secretion.
Gray
D A
DA
Department of Physiology, University of the Witwatersrand, Johannesburg, South Africa.
Downing
C
C
Sayed
N
N
D000064:Acclimatization; D000818:Animals; D000906:Antibodies; D009320:Atrial Natriuretic Factor / Q000097:blood* / Q000276:immunology; D004372:Ducks / Q000502:physiology*; D005260:Female; D006400:Hematocrit; D007262:Infusions, Intravenous; D008297:Male; D011188:Potassium / Q000097:blood; D011817:Rabbits; D012491:Salt Gland / Q000502:physiology*; D012964:Sodium / Q000097:blood; D012965:Sodium Chloride / Q000008:administration & dosage / Q000494:pharmacology; D014882:Water-Electrolyte Balance
D000906:Antibodies; D012965:Sodium Chloride; D009320:Atrial Natriuretic Factor; D012964:Sodium; D011188:Potassium