ULTRASTRUCTURE AND PHYSICO-CHEMICAL PROPERTIES OF GLYCOGEN FROM FETAL RAT LIVER

Ultrastructural appearances and physico-chemical properties of fetal rat liver glycogen were studied. Under electron microscopy, fetal liver glycogen particles were observed as small spheroidal branching bodies which were slightly larger than adult muscle glycogen particles showing 500-800Å in diameter. However, a few of them were demonstrated as large branching structures and were similarly large in size to adult liver glycogen particles. The average chain length and the degree of branching of fetal glycogen determined by the periodate oxidation method resembled adult liver glycogen. The ORD and CD absorption spectra waves of fetal glycogen, measured while adding iodine, showed positive Cotton effect at 540nm which was different from that of adult liver glycogen. Ultracentrifugation analysis demonstrated the sedimentation coefficient of 106.9s. Among adult muscle and hepatoma glycogen, hepatoma glycogen was most similar to fetal glycogen in reference to the physico-chemical examinations as previously described (2, 4, 5).