Possible role of calcitonin gene-related peptide in osmoregulation via the endocrine control of the gill in a teleost, the eel, Anguilla anguilla

Osmoregulation is a major challenge in aquatic animals involving a complex endocrine control. We investigated the potential role of calcitonin gene-related peptide (CGRP, a neuromediator in mammals) in the endocrine control of the gill in a teleost, the eel. Transfer from freshwater to seawater induced an hyperosmolality and a concomitant large increase in plasma CGRP levels. Specific CGRP binding sites were characterized in the gill and their number was up-regulated after seawater transfer. This study suggests that the endocrine control of gill function during osmoregulation may represent an ancient role of CGRP in vertebrates. (c) 2005 Elsevier Inc. All rights reserved.