Charles W. Philpott

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Certain euryhaline teleosts can tolerate media of very high salinity, i.e. greater than that of seawater itself. The osmotic gradient across the integument of these fish is very high and the key to their survival appears to be the enhanced ability of the gill to excrete excess NaCl. These fish provide an opportunity to study morphological and biochemical(More)
Enriched fractions of chloride cells with good ultrastructural integrity have been obtained from gill filaments of the euyhaline teleost, Lagodon rhomboides. The branchial epithelium from seawater-adapted fish was dissociated by gentle mechanical means in a Ca++, Mg++-free balanced salt solution. Density gradient centrifugation of the mixed cell suspensions(More)
Correlated morphological and cytochemical investigations of the branchial epithelium of the pinfish, Lagodon rhomboides, have revealed a cell type that is invariably associated with chloride cells. These cells, termed "accessory cells," have been described previously in the teleost pseudobranch (Dunel and Laurent. J. Microsc. Biol. Cell 16:53-74, 1973) but(More)
A MORPHOLOGICAL BASIS FOR OSMOREGULATION IN THE TELEOSTS WAS STUDIED BY COMPARING THE FINE STRUCTURE OF CHLORIDE CELLS FOUND IN EPITHELIA OF THE GILLS OF THREE SPECIES OF FISH: Fundulus heteroclitus which can survive in a wide range of salinities, and F. similis and F. chrysotus which are usually restricted to salt water and fresh water environments,(More)
Chloride cells represent the sites of branchial osmoregulatory activity of teleosts. The cells undergo characteristic changes with osmotic challenge and the response is mediated by hormones. Either increased salinity or cortisol treatment will elicit well-known changes in chloride cells; these changes are clearly interrelated and may be collectively(More)
The activity of the electrolyte transport enzyme, sodium, potassium-activated adenosine triphosphatase (Na+,K+-ATPase), in the gills of the pinfish, Lagodon rhomboides, increased markedly following transfer of fish from brackish water to seawater. Cytochemical localization of Na+,K+-ATPase via its potassium-dependent phosphatase (K+-NPPase) activity in the(More)
In an effort to determine the subcellular localization of sodium- and potassium-activated adenosine triphosphatase (Na(+), K(+)-ATPase) in the pseudobranch of the pinfish Lagodon rhomboides, this tissue was fractionated by differential centrifugation and the activities of several marker enzymes in the fractions were measured. Cytochrome c oxidase was found(More)