[Incorporation of C-14-glycine in vitro into normal human lymphocytes and those in cases of aberration of chromosome 21].

Since Caspersson 's and Brachet 's investigations it has been very well known that the nucleolus is a cellular center of protein synthesis regulation. Later it has been shown that the nucleolus is the site of ribosome production, that means that it produces one of the basic elements of the cytoplasmatic apparatus of protein synthesis. Morphologic observations demonstrated that the nucleolus in man is formed in close connection with secondary constrictions of acrocentric chromosomes of the D and G groups. These regions contain the nucleolus organizing region (locus NOR). By means of DNA-RNA hybridization in situ it has been established that the secondary constrictions of acrocentric chromosomes contain sequences coding ribosomal RNA synthesis. RNA synthetized on r-DNA matrix contained in NOR is transported to the nucleolus where ribonucleoprotein complexes are formed. Ribosome formation is the result of a complex process. Ribosomes are transported to the cytoplasm where they aggregate into polyribosomes on the rough ergastoplasmic reticulum. In this way the cytoplasmatic aparatus of protein synthesis is formed. Its activity depends on ribosome formation. In view of the above the question arises: will the presence of an additional chromosome coding r-RNA synthesis as in Down's syndrome, i.e. 21 trisomy, influence the course of protein synthesis? Blastic transformation of lymphocytes in vitro induced by phytohaemagglutinin is a convenient model for the study of protein synthesis in cells stimulated to growth and differentiation. This phenomenon has been very well investigated. It is well known that blastic transformation is accompanied by intensification of RNA synthesis, ribosome formation and intensification of protein synthesis. The existing literature data allow to choose adequate methods and time points for the examination of the course of protein synthesis in this model. Venous blood was obtained from 17 healthy humans with normal karyotype and from 15 cases of trisomy 21. After separation of plasma with lymphocytes routine cultures with addition of phaseoline were set up and were incubated 6, 12, 24, 48 and 72 hours. 14C-glycine was added one hour before the termination of the incubation period. Following this the number and differential count of lymphocytes were determined.(ABSTRACT TRUNCATED AT 400 WORDS)