Intranuclear Synthesis of Polyglucose Particles Under Histochemical Conditions in the Normal Rat

Abstract

Polyglucose particles artificially synthesized under histochemical conditions from glucose 1-phosphate by phosphorylase and branching glycosyltransferase in the nuclei of skeletal muscle fibers, satellite cells and endothelial cells of the blood capillary of the normal rat were studied at the electronmicroscopic level.Newly formed polyglucose particles appeared in the karyolymph and interchromatin area of nuclei as a large macromolecular structure of spheroidal branching bodies. The size of intranuclear polyglucose particles ranging from 400 A to 1600 A in diameter was slightly larger than the cytoplasmic particles.There was no evidence that newly formed particles in the nuclei had a relation to the chromatin or the nuclear membrane.

HISTOCHEMICAL AND ELECTRON MICROSCOPIC OBSERVATIONS OF POLYGLUCOSE SYNTHESIZED BY ENZYMES IN THE SINO-ATRIAL NODAL CELL OF RABBITS TREATED WITH Β-Stimulating AND Β-Blocking AGENTS

“…The significance of the intranuclear synthesis of polyglucose in the S-A nodal cells is still unknown, but it may be related to the fact that phosphorylase and glycosyltransferase activities are abnormally stimulated by the treatment of isoproterenol and that synthesis in vitro occurs in the intranuclear matrix among chromosomes. It was also noticed that the newly synthesized polyglucose particles in the S-A nodes of rabbits treated with isoproterenol appeared in the same form as the rosette-like particles shown by Takeuchi et al (1974Takeuchi et al ( , 1975 as spheroidal branching bodies. They were larger in size than native glycogen particles and polyglucose particles under other conditions.…”

“…In addition, the new particles deposited not only in the cytoplasmic matrix, but also in the nuclear matrix. Work has been conducted upon the intranuclear synthesis of glycogen by Karasaki (1971), who used ascites hepatom cells treated with radioactive 14C-glucose, by Amemiya (1970), who used the retinal cells, and by Miyayama et al (1975), who used endothelial and muscle cells with application of the enzyme-histochemical technique. The biologicai significance of the intracellular synthesis of glycogen is still unknown, but intranuclear glycogen has been demonstrated under the light microscope in cases of metabolic disorders such as diabetes and of deviations of cancer metabolism.…”

“…This new polyglucose has histochemical and electron microscopic properties different from native glycogen (Takeuchi and Sasaki 1968, 1970 a b. Takeuchi et al 1975), and the size and the distribution of synthesized polyglucose differ considerably from each other depending on the kinds of tissue cells or enzyme systems (Takeuchi et al 1975).…”

Macromolecular glycogen synthesis induced from enzyme histochemistry.

“…Takeuchi and his associates (11,12,18,19,28,35,37,38,39,40,49) also applied electron microscopic techniques to observe polyglucose or polysaccharide synthesized by enzymes in tissue cells. Takeuchi and M. and H. Miyayama (1972) demonstrated that polyglucose particles synthesized by phosphorylase alone were amorphous or smaller in size than native glycogen particles, whereas polysaccharide particles synthesized under similar conditions by phosphorylase in conjunction with branching glycosyltransferase were generally larger in size than those of native glycogen.…”

Characteristics of Polyglucose Particles Newlysynthesized by the Phosphorylase-Branching Glycosyltransferase System in Various Tissue Cells Under Histochemical Conditions

“…On the other hand, electron microscopic observation of polyglucose synthesized from glucose-l -phosphate by phosphorylase activity was first made by Sasaki and Takeuchi in human muscle fibers (18) . Since then, intracellular polyglucose synthesis has been studied in several kinds of tissue cells under the electron microscope (2,12,13,14,15,17,26,29,30,31,33). Takeuchi and his co-workers found that newly-formed polyglucose particles synthesized from glucose 1-phosphate (Gl-P) by the phosphorylase and branching glycosyltransferase system (PBG-system) under histochemical conditions varied in size, shape and electron-density according to the kind of tissue cells and that they were different from endogenous glycogen particles.…”