CYSTATHIONINE SYNTHESIS AND DEGRADATION IN BRAIN, LIVER AND KIDNEY OF THE DEVELOPING MONKEY

Abstract— The concentration of cystathionine, along with the specific activities of the enzymes involved in its synthesis and degradation, cystathionine synthasc and cystathionase, respectively, have been measured in brain, liver and kidney of the developing Rhesus monkey from mid-gestation, through birth and neonatal life, to maturity. The concentration of cystathionine and the specific activity of cystathionine synthase are low in fetal brain. Both parameters increase slowly after birth and reach values found in adult brain at approx 3 months of postnatal age. The activity of cystathionase in brain is low throughout development.
Liver provides a direct contrast in that the concentration of cystathionine and the specific activity of cystathionine synthase are high in the fetus, decreasing rapidly after birth to values found in the adult by 2 weeks of postnatal age. Cystathionase activity is low in fetal liver and increases slowly after birth reaching values found in adult liver after 2–3 months. Kidney has no more than trace amounts of cystathionine throughout development, higher activity of cystathionine synthase in the fetus than in the adult and high, unchanged activity of cystathionase throughout the period of development studied.
These results indicate that the high concentrations of cystathionine found in primate brain are reached postnatally and suggest that this high concentration of cystathionine may be associated with the functioning of mature brain.