Simple Summary: We lack studies investigating mitochondrial metabolism in the prenatal and early postnatal period in humans, but parallel experiments conducted in a mammalian system are informative about the human condition. Our aim was to study the perinatal metabolic switch in rats—an extremely complex process, associated with tissue proliferation and differentiation together with a rapid oxidative stress response (using techniques including microarrays, qPCR, spectrophotometry and high-performance liquid chromatography).
Out of 1546 mitochondrial genes, 1119 and 827 genes significantly changed expression in rat liver and skeletal muscle, respectively. The most remarkable expression shift occurred in the rat liver at least two days before birth.
Coenzyme Q and mitochondrial metabolism-based evaluation in both the rat model and human tissues showed the same trend: the total CoQ content and mitochondrial metabolism significantly increases after birth, possibly regulated by COQ8A kinase. Our microarray data could serve as a suitable background for finding key factors regulating mitochondrial metabolism and preparation of the foetus for the transition to extra-uterine conditions, or as preliminary data for further studies of the complex mitochondrial metabolism regulation and diagnostics of mitochondrial disorders.