Changes in patterns of S-adenosylmethionine synthetases in fetal and postnatal rat liver

Three isozymes of S-adenosylmethionine synthetase have been measured in the livers of rats from fetal life to maturity. A greater part of gamma-type enzyme is shown to be present in fetus and is joined by alpha- and beta-types during development. The amount of beta-type enzyme activated by dimethyl sulfoxide is very low in the fetus and rises sharply until about the 15th day after birth. The alpha-type enzyme appears after birth and increases in amount to the tenth day.