title: Low Na+ concentration: a factor contributing to diminished uptake and incorporation of amino acids by diapausing mouse blastocysts?
abstract: Uptake and incorporation of 14C amino acids by normal and diapausing blastocysts was found to be Na+ dependent with one exception. Delayed embryos preincubated 25 h in medium containing 124 mM Na+ had labeling characteristics independent of the Na+ concentration present during labeling. Since diapausing embryos preincubated 25 h in low Na+ medium (55mM) retained their Na+ dependent labeling characteristics, delayed blastocysts may be in a low Na+ environment in situ. Low Na+ may explain why delayed blastocysts are unable to utilize radioactive methionine in vivo (Weitlauf and Greenwald, '68).
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001755:Blastocyst / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D051379:Mice; D011247:Pregnancy; D012964:Sodium / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D000596:Amino Acids; D012964:Sodium