No immediate implications for neonatal care; leaves open developmental SR calcium handling in perinatal mammals.
Key Points
This research aims to examine changes in calcium accumulation and ATPase activity of cardiac sarcoplasmic reticulum around the time of birth.
Prepared SR-rich microsomal fractions from foetal and neonatal guinea pigs and rabbits before birth and at one day postpartum.
Analyzed calcium accumulation and ATPase activity in these samples, comparing foetal and adult muscles.
One day before birth, foetal microsomes showed reduced calcium accumulation and ATP hydrolysis compared to maternal controls.
After birth, neonatal cardiac microsomes exhibited increased calcium accumulation, with changes dependent on species, including an uptick in Ca2+ uptake in rabbits and Ca2+ binding in guinea pigs.
The observed increase in calcium accumulation was correlated with a rise in Ca2+-dependent ATPase activity.