Primary cultures of shark rectal gland epithelial cells: A model for hormone-sensitive chloride transport

Abstract

Methods are described for establishing primary monolayer cultures from chloride-secreting epithelial cells of the dogfish shark (Squalus acanthias) rectal gland (SRG). After stimulation, cultures display exceptionally high rates (150 to 250μA/cm2) of transepithelial chloride secretion. Hormones and neurotransmitters which increase cytoplasmic cyclic AMP, cyclic GMP, calcium or phospholipid-derived second messengers are potent secretagogues. Cultures can be analyzed using a variety of morphologic, biochemical, and electrophysiologic methods. These characteristics make SRG cultures a powerful model for delineating the molecular basis of the transmembrane and intracellular signaling networks that stimulate or inhibit secondary active chloride transport in epithelia. Secondary active chloride transport occurs in a variety of epithelia, including those comprising both the proximal and distal segments of vertebrate nephrons.