Sodium pumps in the Malpighian tubule of Rhodnius sp
An. acad. bras. ciênc
;
72(3): 407-12, Sept. 2000. graf
Article
in English
| LILACS
| ID: lil-269392
ABSTRACT
Malpighian tubule of Rhodnius sp. express two sodium pumps the classical ouabain-sensitive (Na+ + K+)ATPase and an ouabain-insensitive, furosemide-sensitive Na+-ATPase. In insects, 5-hydroxitryptamine is a diuretic hormone released during meals. It inhibits the (Na+ + K+)ATPase and Na+ -ATPase activities indicating that these enzymes are involved in fluid secretion. Furthermore, in Rhodnius neglectus, proximal cells of Malpighian tubule exposed to hyperosmotic medium, regulate their volume through a mechanism called regulatory volume increase. This regulatory response involves inhibition of the (Na+ + K+)ATPase activity that could lead to accumulation of active osmotic solute inside the cell, influx of water and return to the normal cell volume. Adenosine, a compound produced in stress conditions, also inhibits the (Na+ + K+)ATPase activity. Taken together these data indicate that (Na+ + K+)ATPase is a target of the regulatory mechanisms of water and ions transport responsible for homeostasis in Rhodnius sp.
Full text:
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Index:
LILACS (Americas)
Main subject:
Rhodnius
/
Sodium-Potassium-Exchanging ATPase
/
Insect Vectors
/
Malpighian Tubules
Limits:
Animals
Language:
English
Journal:
An. acad. bras. ciênc
Journal subject:
Science
Year:
2000
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
Universidade Federal do Rio de Janeiro/BR
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