Dynamics of proglycogen and macroglycogen in hepatocytes of normal and cirrhotic rat liver at various stages of glycogenesis
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
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