The Herpetological Journal

pp.23-26

Authors: Mario Diaz And Antonio Lorenzo

Abstract: Plasma concentrations of aldosterone, sodium and potassium were measured in the lizard, Gallotia galloti. Aldosterone concentrations in control animals were 29.48 ± 8.65 ng/dl, which falls within the range reported for this hormone in mammals. Peripheral sodium and potassium concentrations were 1 32.81 .± 2.28 and 5.77 ± 0.32 meq/I, respectively. Plasma aldosterone and sodium were negatively correlated. A positive relationship could be established between potassium concentration and aldosterone levels. Acute or chronic administration of exogenous aldosterone increased the circulating levels of this hormone, being maximal in chronically treated animals. However, although plasma concentrations of aldosterone were augmented by acute administration, the sodium concentration in the plasma was only elevated by chronic treatment. No further changes to potassium concentration could be observed under primary hyperaldosteronism conditions. The extent to which aldosterone may be implicated in the regulation of sodium and potassium transport in reptiles and its possible action on postrenal structures of electrolyte transport are discussed.