- MeSH
- Calcium-Transporting ATPases biosynthesis MeSH
- Thyroid Hormones physiology MeSH
- Rats MeSH
- Myocardium metabolism MeSH
- Sodium-Calcium Exchanger biosynthesis MeSH
- Sarcolemma metabolism MeSH
- Heart growth & development MeSH
- Gene Expression Regulation, Developmental MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Animals MeSH
- Publication type
- Comparative Study MeSH
The aim of this study was to examine the relationship between sarcolemmal Na(+)-Ca2+ exchangers and sarcoplasmic reticulum (SR) Ca(2+) -ATPase (SERCA2) expression and the developmental differences in cardiac Ca2+ handling. Postnatal steady-state mRNA and protein levels were analysed in rat ventricular myocardium by Northern and immunoblot analysis, respectively. This was compared to Na+ gradient-induced and SR oxalate-supported Ca2 transport in isolated membranes. Na(+)-Ca2+ exchanger mRNA declined by 75% between day 1 and 30, whereas SR Ca2+ ATPase mRNA levels increased by 97% during this period. The Na(+)-Ca2+ exchanger mRNA/Ca(2+)-ATPase mRNA ratio was found to be inversely related to post-natal age. The changes in mRNA levels were associated with corresponding developmental differences in the Ca2+ transport activities of the respective membrane proteins. In crude membranes, the Na(+)-dependent Ca2+ transport activity (at 75 microM Ca2+) declined gradually (P < 0.01; mean +/- S.E.) from 17.7 +/- 2.4 nmoles Ca2+/g wet tissue/2s at day 1-3 (n = 5) to a value of 4.2 +/- 1.1 at day 40 (n =4). Conversely, SR Ca2+ uptake increased (P < 0.01) 2.6-fold during this period. The inversely related changes in the post-natal expression and function of the Na(+)-Ca2+ exchanger and SR Ca(2+)-ATPase suggest a coordinated control at the pretranslational level of the cellular Ca2+ transport processes mediated by the two membrane proteins.
- MeSH
- Calcium-Transporting ATPases biosynthesis MeSH
- Gene Expression * MeSH
- Rats MeSH
- RNA, Messenger biosynthesis metabolism MeSH
- Myocardium * metabolism MeSH
- Blotting, Northern MeSH
- Oxalates pharmacology MeSH
- Rats, Wistar MeSH
- Sarcolemma * metabolism MeSH
- Sarcoplasmic Reticulum * metabolism MeSH
- Heart physiology growth & development MeSH
- Heart Rate MeSH
- Aging * metabolism MeSH
- In Vitro Techniques MeSH
- Carrier Proteins * biosynthesis MeSH
- Calcium * metabolism MeSH
- Blotting, Western MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Animals MeSH
- Publication type
- Research Support, Non-U.S. Gov't MeSH
- Comparative Study MeSH
