Open AccessStrong alkalinization in the anterior midgut of larval yellow fever mosquitoes ( Aedes aegypti ): involvement of luminal Na + /K + ‐ATPase
Author(s) -
Onken Horst,
Patel Malay,
Javoroncov Margarita,
Izeirovski Sejmir,
Moffett Stacia B.,
Moffett David F.
Publication year - 2008
Publication title -
journal of experimental zoology part a: ecological genetics and physiology
Language(s) - English
Resource type - Journals
eISSN - 1932-5231
pISSN - 1932-5223
DOI - 10.1002/jez.512
Subject(s) - midgut , aedes aegypti , biology , ouabain , atpase , larva , microbiology and biotechnology , biochemistry , enzyme , sodium , ecology , chemistry , organic chemistry
Recently, Na + /K + ‐ATPase has been detected in the luminal membrane of the anterior midgut of larval yellow fever mosquitoes ( Aedes aegypti ) with immunohistochemical techniques. In this study, the possible involvement of this ATPase in strong alkalinization was investigated on the level of whole larvae, isolated and perfused midgut preparations and on the molecular level of the Na + /K + ‐ATPase protein. Ouabain (5 mM) did not inhibit the capability of intact larval mosquitoes to alkalinize their anterior midgut. Also in isolated and perfused midgut preparations the perfusion of the lumen with ouabain (5 mM) did not result in a significant change of the transepithelial voltage or the capacity of luminal alkalinization. Na + /K + ‐ATPase activity was completely abolished when KCl was substituted with choline chloride, suggesting that the enzyme cannot act as an ATP‐driven Na + /H + ‐exchanger. Altogether the results of the present investigation indicate that apical Na + /K + ‐ATPase is not of direct importance for strong luminal alkalinization in the anterior midgut of larval yellow fever mosquitoes. J. Exp. Zool. 311A:155–161, 2009 . © 2008 Wiley‐Liss, Inc.