Linked Life Data

2429881

Source:http://linkedlifedata.com/resource/pubmed/id/2429881

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1986-12-11
pubmed:abstractText
Relationships between the Na+ dependent amino acid uptake displayed by fertilized sea urchin eggs and the electrochemical gradient of Na+ was investigated. The time course of Na+ content and valine or alanine uptake was simultaneously monitored in Na+ loaded eggs [by fertilization in K+-free artificial sea water (OK-ASW), or by using monensin, antimycin, cyanide, or ciguatoxin]. Our results demonstrate that the uphill amino acid uptake follows the "Na+ gradient hypothesis." Subsequent fertilization of eggs Na+ depleted by ammonia for 40 min stimulates to a great extent the development of amino acid uptake as compared with controls eggs. By using simultaneous change of external and intracellular Na+ concentration, we studied the specific role of this ion. An increase in internal Na+ inhibits the uptake through trans inhibitory action while an increase in external Na+ stimulates the efficiency of the uptake system. In eggs fertilized since 30 min, hyperpolarization obtained in K+-free ASW stimulates amino acid uptake while depolarization (transfer from K+ free ASW to ASW) inhibits it. This potential-dependent effect developed after fertilization with a time course similar to that the establishment of K+ conductance described by R. A. Steinhardt, L. Lundin, and D. Mazia (1971, Proc. Natl. Acad. Sci. USA 68, 2426-2430). In conclusion, our results point out that slight modulations in the activity of the Na+ pump can widely affect the amino acid uptake, suggesting that activation of Na+/K+ ATPase has a key role in the stimulation of amino acid transport.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0012-1606
pubmed:author
pubmed:issnType
Print
pubmed:volume
118
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
19-27
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Regulatory and energetic role of Na+ in amino acid uptake by fertilized sea urchin eggs.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't