ANG II-induced attenuation of duck salt gland secretion does not depend upon the release of adrenal catecholamines.
Pekin ducks (Anas platyrhynchos) were bilaterally adrenalectomized (ADX) using a two-stage procedure and given daily i.m. injections of 1 mg kg bw(-1) of dexamethasone (DEXA), a steroid lacking mineralocorticoid activity, and 0.9% saline drinking water ad libitum to counterbalance renal losses of salt and water. Mean arterial blood pressure (mmHg) fell from 161+/- 3.7 (intact controls) to 116 +/- 6.9 (bilateral ADX+DEXA), a decrease of 27%, but heart rates (HR) were unchanged. The nasal salt glands were fully active after ADX + DEXA. Rates of fluid secretion and electrolyte and osmolal concentrations were unchanged. Secretion stopped, then rebounded several minutes later if ADX + DEXA ducks were injected i.v. with 1 microg of [Asn(1),Val(5)]-angiotensin II (ANG II) kg bw(-1) which showed that attenuation was not adrenal catecholamine-dependent.
Butler
David Gordon
DG
Department of Zoology, University of Toronto, ON, Canada. dbutler@zoo.utoronto.ca
Lam
Wallace
W
Tong
Jeff
J
D000311:Adrenal Glands / Q000378:metabolism; D000315:Adrenalectomy; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003907:Dexamethasone / Q000008:administration & dosage; D004298:Dopamine / Q000097:blood; D004372:Ducks / Q000378:metabolism*; D004837:Epinephrine / Q000097:blood; D006339:Heart Rate / Q000187:drug effects; D017817:Nasal Lavage Fluid / Q000737:chemistry; D009638:Norepinephrine / Q000097:blood; D011188:Potassium / Q000032:analysis / Q000097:blood; D012491:Salt Gland / Q000187:drug effects* / Q000378:metabolism; D012964:Sodium / Q000032:analysis / Q000097:blood; D012965:Sodium Chloride / Q000008:administration & dosage
D000804:Angiotensin II; D012965:Sodium Chloride; D003907:Dexamethasone; D012964:Sodium; D011188:Potassium; D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine