Expression and activity of the Ca(2+)-atpase enzyme in human neonatal erythrocytes
I Kocsis1, B Vásárhelyi, E Héninger
1First Department of Paediatrics, Semmmelweis Medical University, Budapest, Hungary. kopist@gyer1.sote.hu
Insights
Plasma membrane Ca(2+)-ATPase (PMCA) abundance and activity change during early development. Pre-term infants may have immature PMCA enzyme function, impacting calcium regulation.
Area of Science:
- Biochemistry
- Physiology
- Developmental Biology
Background:
- The plasma membrane Ca(2+)-ATPase (PMCA) is crucial for maintaining calcium ion (Ca2+) homeostasis.
- Understanding PMCA's role in perinatal development is essential for assessing infant health.
Purpose of the Study:
- To investigate changes in PMCA abundance and activity in human erythrocytes during the perinatal period.
- To compare PMCA in pre-term neonates, full-term neonates, and young children (1-4 years).
Main Methods:
- Analysis of PMCA molecule abundance and enzyme activity in erythrocyte samples.
- Comparison across different age groups: pre-term neonates, full-term neonates, and children aged 1-4 years.
Main Results:
- Lower abundance of the PMCA 4b isoform correlated with reduced enzyme activity in full-term neonates versus children.
- Pre-term neonates had increased PMCA molecule numbers but similar total enzyme activity compared to full-term neonates.
Conclusions:
- PMCA molecule abundance undergoes significant alterations during perinatal development.
- The findings suggest potential functional immaturity of the PMCA enzyme in pre-term infants, despite higher molecule counts.
Abstract:
The plasma membrane Ca(2+)-ATPase (PMCA) is one of the main regulators of Ca(2+) homeostasis. We studied the perinatal alteration of the abundance and the activity of PMCA molecules in human erythrocytes in pre-term and full-term neonates and children at the age of 1-4 years. The lower abundance of the 4b isoform was associated with lower enzyme activity in full-term neonates compared to children. Although the number of PMCA molecules was higher in pre-term neonates, their total PMCA activities were identical to those of full-term neonates. Our findings suggest that the abundance of PMCA molecules changes during the perinatal development. The same activity at higher enzyme molecule numbers might indicate a potential immaturity of the enzyme in the pre-term infant.
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