Prolactin receptor and interrenal hormone levels in adult Xenopus laevis (Daudin) exposed to hyperosmotic stress and treated with metyrapone.

In an attempt to determine whether a direct relationship exists between the opposite variations in prolactin (PRL) receptor and interrenal hormone (aldosterone and corticosterone) levels shown by Xenopus adult females (transferred for 24 hours in brackish water) were treated with metyrapone, an inhibitor of interrenal hormone synthesis. In the animals exposed to osmotic stress and treated with metyrapone a significant drop took place only in radioimmunoassayed serum aldosterone levels. Conversely a significant rise in PRL receptors of the epidermis and kidney (biochemical study) was recorded in the same group of animals compared to those exposed to the osmotic stress but without metyrapone treatment. These results suggest that the variations in the levels of interrenal hormones and PRL receptors, detected in Xenopus specimens transferred to brackis water would not simply be a matter of coincidence but the outcome of a more direct cause/effect interdependence.