Developmental changes in mRNA encoding cardiac Na+/H+ exchanger (NHE-1) in rabbit.
The faster recovery of cardiac contractility in newborn rabbit hearts during acute acidosis compared to adult hearts correlates with greater cellular activity of the Na+/H+ exchanger. We quantified mRNA encoding Na+/H+ exchanger-1 (NHE-1) in rabbit ventricles of fetal (27 days gestation), newborn (2-5 days), and adult (> 6 months) New Zealand white rabbits using reverse transcription-polymerase chain reaction (RT-PCR) and RNase protection assay, with GAPD mRNA as standard. Both RT-PCR and RNase protection assay revealed similar (p > 0.05) cardiac levels of NHE-1 mRNA in fetal and newborn hearts, while NHE-1 mRNA in these hearts was 1.7x and 1.6x greater than in adult hearts by both RT-PCR and RNase protection assay. These developmental changes in NHE-1 mRNA correlate with the developmental changes in Na+/H+ activity in sarcolemmal vesicles purified from rabbit heart.
Chen
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F
Division of Pediatric Cardiology, University of California, Los Angeles 90095-1752, USA.
Jarmakani
J M
JM
Van Dop
C
C
D000818:Animals; D000831:Animals, Newborn; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D006352:Heart Ventricles / Q000254:growth & development / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009206:Myocardium / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism*; D011817:Rabbits; D017923:Sodium-Hydrogen Exchangers / Q000235:genetics*
D017931:DNA Primers; D012333:RNA, Messenger; D017923:Sodium-Hydrogen Exchangers; C069139:growth factor-activatable Na-H exchanger NHE-1