Abstract
<div class="line" id="line-5"> The rectal gland of the European dogfish (Scyliorhinus canicula), in combination with the kidney and gill, works to preserve plasma electrolyte balance in the presence of a constant uptake of NaCl from sea water through permeable body surfaces (mainly the gill) and the intermittent uptake of NaCl from food and ingested sea water by the gut. This gland is composed of a network of secretory tubules, veins, and arteries and has a central region consisting of a major vein and a central canal that terminates at the drainage duct of the rectum. The secretory tubules actively transport NaCl from the blood into the tubular lumen at concentrations of approximately 0.5 M (twice that of the plasma), and this fluid then drains from the ducts into the central canal before being excreted from the fish. The cells that make up the secretory tubules possess numerous mitochondria and a greatly expanded basolateral plasma membrane that typifies cells engaged in transepithelial ion transport. These epithelial cells exhibit high levels of expression of the Na, K ‐ATPase (sodium pump) and can easily be isolated and cultured from the dogfish rectal gland using a collagenase perfusion technique. The cell cultures provide a suitable model for studying the hormonal and ionic regulation of Na, K‐ATPase activity and expression. In this report we describe how raising the extracellular sodium concentration of the growth medium induces a transient but marked increase in Na, K‐ATPase activity in cell homogenates.</div>
Original language | American English |
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Journal | Annals of the New York Academy of Sciences |
Volume | 834 |
DOIs | |
State | Published - Nov 1997 |
Keywords
- Dogfish rectal cland
- Epithelial cells
- Extra-cellular sodium
- Intra-cellular sodium
- K-ATPase
- Na
DC Disciplines
- Biology