SHORT COMMUNICATION

Developmental Changes of Cytochrome c Oxidase and Citrate Synthase in Rat Heart Homogenate

Z. DRAHOTA1, M. MILEROVÁ2, A. STIEGLEROVÁ2, J. HOUŠTĚK1,
B. OŠŤÁDAL2

1Center for Integrated Genomics and 2Center for Experimental Cardiovascular Research, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic

Received April 1, 2003
Accepted August 22, 2003

Summary
Activity of cytochrome c oxidase and citrate synthase in rat heart homogenates was determined in 5-, 15-, 28- and 60-day-old rats. The activity of both enzymes increased during postnatal development but their changes followed different kinetics. The membrane-bound cytochrome c oxidase reached its adult values during the early postnatal period, i.e. between days 5 and 15, whereas soluble matrix-localized citrate synthase also continued to increase between days 15 and 60. Our data indicate a relative excess of cytochrome c oxidase in neonatal cardiocytes.

Key words
Rat heart • Postnatal development • Cytochrome c oxidase • Citrate synthase