Effect of volume expansion and veratrine on salt gland secretion in the goose

The influence of acute intravascular volume expansion on salt gland secretion of conscious, adult geese was investigated. The intravenous administration of 5% dextran in Krebs-bicarbonate-Ringer solution in an amount equivalent to 30% of the estimated blood volume caused a transient but highly significant increase in salt gland secretion independent of changes in plasma osmolality or sodium concentration. Intravenous veratrine (60 microng) caused a similar increase in salt gland secretion only when administered after the volume load. Intravenous 5% NaCl always caused a prolonged and significant increase in salt gland secretion which was not potentiated by veratrine. Volume expansion and hypertonic saline caused a significant tachycardia while veratrine caused a significant bradycardia. It is concluded that a volume component may contribute to the initiation of salt gland secretion in the goose and that the peripheral receptor involved is most likely vascular in origin.