Brain sulfatide and non-lipid sulfate metabolism in hypothyroid rats

Neonatal hypothyroidism reduced the concentration of sulfatide in myelin and synaptosomes isolated from brains of 20-21 day old rats. The in vivo incorporation of 35SO4 into sulfatide of myelin, microsomal, animals, as was the incorporation of the isotope into non-lipid sulfate (sulfated glycoproteins and mucopolysaccarides) of microsomal and synaptosomal fractions. In contrast, when animals were made hypothyroid at one month of age, no depletion of brain sulfatide or alteration of incorporation of 35SO4 into sulfatide was found, although incorporation of the isotope into non-lipid sulfate of myelin, mitochondria and synaptosomes was increased by this treatment. These results indicate that the metabolism of sulfatide and non-lipid sulfate of brain membranes is much more susceptible to alteration by hypothyroidism in neonatal than may alter the metabolims of sulfatide and non-lipid sulfate in neuronal as well as myelin membranes.