Dynamics of proglycogen and macroglycogen in hepatocytes of normal and cirrhotic rat liver at various stages of glycogenesis
- 34 Downloads
The content and structure of glycogen in hepatocytes of normal and cirrhotic rat liver were examined at different time intervals after glucose administration to starving animals. We used an original cytofluorimetric method for detection and quantification of proglycogen (PG) and macroglycogen (MG) of isolated hepatocytes. The method is based on the use of reagents of the Schiff type with different spectral characteristics. The content of MG in hepatocytes of control rats was increased by 52% (p < 0.01) as early as after 10 min. The MG content in the cirrhotic liver cells was increased by 43% (p < 0.05) only 20 min after glucose administration to the starving animals. The correlation coefficient between MG content and the total glycogen content at various stages of glycogenesis in rats of both groups was from 0.90 to 0.99 (p < 0.001). Increase in the PG content in hepatocytes of control rats was observed in intervals of 10–30 and 45–75 min. The PG content in cirrhosis was increased only in 60 min after the beginning of glycogenesis, but in 120 min it was 1.5 times higher than the control values (p < 0.001). The correlation coefficients between PG and the total glycogen content in the cells were on average 0.86 (p < 0.001) and 0.77 (p < 0.001) in the control and experimental groups, respectively. Thus, the change in the total glycogen content in hepatocytes of normal and cirrhotic liver are associated mainly with changes in the MG level. The contribution of PG was most significant in normal liver at the beginning of glycogenesis (10–30 min); in cirrhotic liver, at later stages (75–120 min).
Keywordsproglycogen macroglycogen hepatocytes glycogen synthesis liver cirrhosis glucose
Unable to display preview. Download preview PDF.
- Bröjer, J., Proglycogen and macroglycogen in equine skeletal muscle, Doctoral Thesis Swedish University of Agricultural Sciences, Uppsala, 2006.Google Scholar
- Brodsky, V.Ya. and Nechaeva, N.V., Ritm sinteza belka (Rhythm of Protein Synthesis), Moscow: Nauka, 1988.Google Scholar
- Judd, C., Lomako, J., Lomako, W.M., Ozdemir, Y., and Whelan, W.J., Proglycogen: an intermediate in glycogen synthesis, FASEB J,, 1992, vol. 6, pp. A1520.Google Scholar
- Kudryavtseva, M.V., Zavadskaya, E.E., Skorina, A.D., Smirnova, S.A., and Kudryavtsev, B.N., The method of obtaining isolated liver cells of material lifetime puncture biopsies, Lab. Delo, 1983, vol. 9, pp. 21–22.Google Scholar
- Kudryavtseva, M.V., Emelyanov, A.V., Sakuta, G.A., Skorina, A.D., Sleptsova, L.A., and Kudryavtsev, B.N., A cytofluorometric study of glycogen contents and its fractions in hepatocytes of patients with different causation of liver cirrhosis, Tsitologiya, 1992, vol. 34, no. 11–12, pp. 100–107.Google Scholar
- Planaguma, A., Claria, J., Miquel, R., Lopez-Parra, M., Titos, E., Masferrer, J.L., Arroyo, V., and Rodes, J., The selective cyclooxygenase-2 inhibitor SC-236 reduces liver fibrosis by mechanisms involving non-parenchymal cell apoptosis and PPARgamma activation, FASEB J., 2005, vol. 19, pp. 1120–1122.PubMedGoogle Scholar
- Rozenfeld, E.L. and Popova, I.A., Vrozhdennye narusheniya obmena glikogena (Inborn Errors of Glycogen Metabolism), Moscow: Meditsina, 1989.Google Scholar
- Sherlock, Sh. and Dooley, J., Liver and Biliary Tract Diseases, Moscow: GEOTAR-media, 2002.Google Scholar
- Tagliabracci, V.S., Turnbull, J., Wang, W., Girard, J.M., Zhao, X., Skurat, A.V., Delgado-Escueta, A.V., Minassian, B.A., Depaoli-Roach, A.A., and Roach, P.J., Laforin is a glycogen phosphatase, deficiency of which leads to elevated phosphorylation of glycogen in vivo, Proc. Natl. Acad. Sci. U.S.A., 2007, vol. 104, pp. 19262–19266.CrossRefPubMedCentralPubMedGoogle Scholar
- Wilson, R.J., Relating glycogenin protein levels and glycogen content post-contraction in human and rodent skeletal muscle, A Thesis for the Degree of Doctor of Philosophy, University of Guelph, 2009.Google Scholar