Differentiation of the Chloride Extrusion Mechanism During Seawater Adaptation of a Teleost Fish, The Cichlid Sarotherodon Mossambicus

摘要: Opercular membranes isolated from the freshwater-adapted euryhaline teleost, Sarotherodon mossambicus , and mounted in Ussing-style chambers, have low conductance current do not actively transport chloride. In contrast, seawater-adapted S. high generate large currents representing net chloride extrusion. Full development of this secretion process requires 1-2 weeks, time-course which provides first unambiguous measurement changes extrarenal salt associated with a teleost's adaptation to seawater. Tissues fish contain typical cells, when observed electron microscope, appear as cells fluorescence microscopy after staining dimethylaminostyrylaethylpyridiniumiodine. These are absent freshwater tissue, although rudimentary present, appearing small microscopy. Following seawater transfer, number increases only during 3 days. Subsequent cell hypertrophy is highly correlated quantity data strongly implicate salt-secretory cell-type. When cortisol was injected into fish, density increased but activated. It appears that extrusion involves numbers (controlled, at least part, by cortisol) differentiation including activation membrane active-transport sites. The opercular valuable model for studying these physiological morphological events.