Hormonal regulation of active chloride transport in the dogfish rectal gland

Active transport of chloride is modulated by cyclic AMP in the rectal gland of Squalus acanthias. Vasoactive intestinal peptide (VIP) specifically activates the production of cyclic AMP by the gland and stimulates the secretion of chloride. Somatostatin inhibits VIP-induced secretion but has no effect alone. Both these peptides are present in the dogfish shark and may play an important role in electrolyte homeostasis.