Karpatkin M.D. Department of Pediatrics Research Summary Certain plasma proteins, including coagulation zymogens, their inhibitors, and their co-factors, contribute to normal hemostasis. The zymogens and inhibitors are lower in the newborn human and other mammals than in the adult with significant correlation with gestational age. In the preterm infant, levels may be inadequate for normal hemostasis.
Levels rise rapidly postnatally and then more slowly throughout childhood and adolescence.
Recent data suggest that this rise continues throughout life into old age. Our laboratory has investigated the possible mechanisms responsible for the different levels in infants and adults. The cDNA for rabbit prothrombin was cloned to study the transcription of prothrombin in the fetal and adult rabbit liver. We demonstrated that transcription is not reduced in the fetus. Furthermore, Western blotting of protein extracts of fetal and adult liver showed equal amounts of intrahepatic prothrombin in the fetus and adult, both in the human and rabbit.