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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
3
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pubmed:dateCreated |
1994-10-19
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pubmed:abstractText |
The functional significance of the apical vacuolar-type proton pump (V-ATPase) in Drosophila Malpighian tubules was studied by measuring the intracellular pH (pHi) and luminal pH (pHlu) with double-barrelled pH-microelectrodes in proximal segments of the larval anterior tubule immersed in nominally bicarbonate-free solutions (pHo 6.9). In proximal segments both pHi (7.43 +/- 0.20) and pHlu (7.10 +/- 0.24)) were significantly lower than in distal segments (pHi 7.70 +/- 0.29, pHlu 8.09 +/- 0.15). Steady-state pHi of proximal segments was much less sensitive to changes in pHo than pH of the luminal fluid (delta pHlu/delta pHo was 0.49 while delta pHi/delta pHo was 0.18; pHo 6.50-7.20). Re-alkaliniziation from an NH4Cl-induced intracellular acid load (initial pHi recovery rate 0.55 +/- 0.34 pH.min-1) was nearly totally inhibited by 1 mmol.l-1 KCN (96% inhibition) and to a large degree (79%) by 1 mumol.l-1 bafilomycin A1. In contrast, both vanadate (1 mmol.l-1) and amiloride (1 mmol.l-1) inhibited pHi recovery by 38% and 33%, respectively. Unlike amiloride, removal of Na+ from the bathing saline had no effect on pHi recovery, indicating that a Na+/H+ exchange is not significantly involved in pHi regulation. Instead pHi regulation apparently depended largely on the availability of ATP and on the activity of the bafilomycin-sensitive proton pump.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Acids,
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Triphosphatases,
http://linkedlifedata.com/resource/pubmed/chemical/Ammonium Chloride,
http://linkedlifedata.com/resource/pubmed/chemical/Antiporters,
http://linkedlifedata.com/resource/pubmed/chemical/Buffers,
http://linkedlifedata.com/resource/pubmed/chemical/Hydrogen,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium-Hydrogen Antiporters
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pubmed:status |
MEDLINE
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pubmed:issn |
0174-1578
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
164
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
238-46
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pubmed:dateRevised |
2009-6-8
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pubmed:meshHeading |
pubmed-meshheading:8089311-Acids,
pubmed-meshheading:8089311-Adenosine Triphosphatases,
pubmed-meshheading:8089311-Ammonium Chloride,
pubmed-meshheading:8089311-Animals,
pubmed-meshheading:8089311-Antiporters,
pubmed-meshheading:8089311-Buffers,
pubmed-meshheading:8089311-Cell Membrane,
pubmed-meshheading:8089311-Drosophila,
pubmed-meshheading:8089311-Homeostasis,
pubmed-meshheading:8089311-Hydrogen,
pubmed-meshheading:8089311-Hydrogen-Ion Concentration,
pubmed-meshheading:8089311-Intracellular Membranes,
pubmed-meshheading:8089311-Malpighian Tubules,
pubmed-meshheading:8089311-Potassium-Hydrogen Antiporters,
pubmed-meshheading:8089311-Vacuoles
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pubmed:year |
1994
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pubmed:articleTitle |
Intracellular pH regulation by the plasma membrane V-ATPase in Malpighian tubules of Drosophila larvae.
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pubmed:affiliation |
Institut für Allgemeine und Spezielle Zoologie, Justus-Liebig-Universität, Giessen, Germany.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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