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.