Sensitivity of the receptors for salt-gland secretion in the domestic duck and goose

Abstract

1. 1. The amount of NaCl required to initiate salt-gland secretion during the i.v. infusion of hypertonic solutions was found to be 8–29 m-moles NaCl/kg body-weight in the domestic duck but only 1·9-2·1 m-moles/kg in the domestic goose. 2. 2. In the duck, secretion started when plasma [Na] was increased by 6·9-8·6 per cent, and in the those when plasma [Na] was increased by 0–2·7 per cent, [Cl] by 2·5-5·4 per cent and osmolality by 0·3-2·2 per cent. 3. 3. Taking these and other published data from different species, a significant, inverse, exponential relationship is seen between the percentage increase in plasma [Na] required to initiate salt-gland secretion and body-weight, indicating that the receptors for secretion are more sensitive in larger birds.