Effects of hypophysectomy and thyroidectomy on salt balance in the plethodontid salamanders, Desmognathus fuscus and Desmognathus monticola

Abstract

Hypophysectomy significantly reduced serum sodium levels in Desmognathus fuscus and D. monticola . Prolactin, corticosterone or aldosterone replacement failed to restore serum sodium to control levels. Hypophysectomy also led to decreases in in vitro integumental potential difference and shortcircuit current, which were not restored to control levels by prolactin or corticosterone. Thyroidectomy significantly reduced the level of serum sodium in D. monticola , but it increased in vitro potential difference and short-circuit current. Thyroxine treatment of either hypophysectomized or thyroidectomized D. monticola completely restored serum sodium, potential difference and short-circuite current to control levels.