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<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>S. D. McCormick</dc:contributor>
  <dc:creator>J. M. Mancera</dc:creator>
  <dc:date>2000</dc:date>
  <dc:description>&lt;p&gt;The rapid activation of gill Na&lt;sup&gt;+&lt;/sup&gt;,K&lt;sup&gt;+&lt;/sup&gt;-ATPase was analyzed in the mummichog (&lt;i&gt;Fundulus heteroclitus&lt;/i&gt;) and Atlantic salmon (&lt;i&gt;Salmo salar&lt;/i&gt;) transferred from low salinity (0.1 ppt) to high salinity (25–35 ppt). In parr and presmolt,&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Salmo salar&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;gill Na&lt;sup&gt;+&lt;/sup&gt;,K&lt;sup&gt;+&lt;/sup&gt;-ATPase activity started to increase 3 days after transfer. Exposure of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Fundulus heteroclitus&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;to 35 ppt seawater (SW) induced a rise in gill Na&lt;sup&gt;+&lt;/sup&gt;,K&lt;sup&gt;+&lt;/sup&gt;-ATPase activity 3 hr after transfer. After 12 hr, the values dropped to initial levels but showed a second significant increase 3 days after transfer. The absence of detergent in the enzyme assay resulted in lower values of gill Na&lt;sup&gt;+&lt;/sup&gt;,K&lt;sup&gt;+&lt;/sup&gt;-ATPase, and the rapid increase after transfer to SW was not observed. Na&lt;sup&gt;+&lt;/sup&gt;,K&lt;sup&gt;+&lt;/sup&gt;-ATPase activity of gill filaments in vitro for 3 hr increased proportionally to the osmolality of the culture medium (600 mosm/kg &amp;gt; 500 mosm/kg &amp;gt; 300 mosm/kg). Osmolality of 800 mosm/kg resulted in lower gill Na&lt;sup&gt;+&lt;/sup&gt;,K&lt;sup&gt;+&lt;/sup&gt;-ATPase activity relative to 600 mosm/kg. Increasing medium osmolality to 600 mosm/kg with mannitol also increased gill Na&lt;sup&gt;+&lt;/sup&gt;,K&lt;sup&gt;+&lt;/sup&gt;-ATPase. Cycloheximide inhibited the increase in gill Na&lt;sup&gt;+&lt;/sup&gt;,K&lt;sup&gt;+&lt;/sup&gt;-ATPase activity observed in hyperosmotic medium in a dose-dependent manner (10&lt;sup&gt;–4&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;M &amp;gt; 10&lt;sup&gt;–5&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;M &amp;gt; 10&lt;sup&gt;–6&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;M). Actinomycin D or bumetanide in the culture (doses of 10&lt;sup&gt;–4&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;M, 10&lt;sup&gt;–5&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;M, and 10&lt;sup&gt;–6&lt;/sup&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;M) did not affect gill Na&lt;sup&gt;+&lt;/sup&gt;,K&lt;sup&gt;+&lt;/sup&gt;-ATPase. Injection of fish with actinomycin D prior to gill organ culture, however, prevented the increase in gill Na&lt;sup&gt;+&lt;/sup&gt;,K&lt;sup&gt;+&lt;/sup&gt;-ATPase activity in hyperosmotic media. The results show a very rapid and transitory increase in gill Na&lt;sup&gt;+&lt;/sup&gt;,K&lt;sup&gt;+&lt;/sup&gt;-ATPase activity in the first hours after the transfer of&lt;span&gt;&amp;nbsp;&lt;/span&gt;&lt;i&gt;Fundulus heteroclitus&lt;/i&gt;&lt;span&gt;&amp;nbsp;&lt;/span&gt;to SW that is dependent on translational and transcriptional processes.&lt;span id="_mce_caret" data-mce-bogus="1" data-mce-type="format-caret"&gt;&lt;span&gt;&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1002/1097-010X(20000901)287:4&lt;263::AID-JEZ1&gt;3.0.CO;2-I</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Wiley</dc:publisher>
  <dc:title>Rapid activation of gill Na+, K+-ATPase the euryhaline teleost Fundulus heteroclitus</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>