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Morphological and cytophotometric investigations have been performed on giant cells of the rabbit trophoblast to reveal a mechanism of nuclei polyploidization and define the level of polyploidy. The character of endomitotic chromosomes is found to differ and depend largely on the degree of nuclei polyploidy. Small chromosomes were found in nuclei with low levels of polyploidy. For highly polyploid nuclei, two stages are distinguished. In the first case condensed chromosomes join into bundles resembling Riesenchromosomen in plants, whereas in the second, decondensed chromosomal threads separate and disperse in the karyoplasm. The splitting does not involve nuclei-forming chromosomes in the region of the nucleolar organiser. The degree of polyploidy was determined on the 15th day of development. It was found that giant cell nuclei contain DNA in amounts corresponding to 32-512 chromosomal sets. Most of the nuclei have levels of 128c and 256c. Highly-polyploid nuclei disintegrate into small nuclei with the degree of polyploidy varying from 1c to 32c. Di- tri- and tetraploid nuclei predominate.

The concentrations of total glycogen (TG) and its labile (LF) and stable (SF) fractions were determined in hepatocytes of portal and central zones of the normal human liver and in the liver of patients with cirrhosis of viral and alcohol aetiologies. Using PAS reaction, TG, LF and SF were revealed in histological sections of the material obtained by the liver punch biopsies. The concentrations of TG and its fractions were measured by televisional cytophotometry. In liver cirrhosis, the concentrations of TG, LF and SF in both zones of the hepatic lobule have been found to be much higher than in the normal liver. It has been shown that the ratio of the hepatocyte TG concentrations in the portal zone to the central zone both in the normal liver and in viral cirrhosis exceeds 1.0, amounting to 1.264 +/- 0.021 and 1.030 +/- 0.009, respectively. The glycogen fraction composition in the cells of both the liver lobule zones in viral cirrhosis does not differ significantly from the norm. On the contrary, in the liver of patients with alcoholic cirrhosis, the ratio of the TG concentrations in the portal zone to the central zone is reduced to 0.815 +/- 0.016 and is accompanied by qualitative changes of the glycogen composition.

Using cytofluorimetric and biochemical methods, the content of glycogen and its labile and stable fractions, as well as activities of glucose-6-phosphatase (EC 3.1.3.9), glycogen phosphorylase (EC 2.4.1.1) and glycogen synthase (EC 2.4.1.11) were determined in the rat liver for 6 months after chronic poisoning of the animals with CCl4 and then at 1, 3, and 6 months after the end of the poisoning. One group of rats was given a standard diet, the other, a high-carbohydrate diet. The 6-month long chronic intoxication with CCl4 was shown to produce development of typical liver cirrhosis characterized by a 2·8-fold increase in the total glycogen content in hepatocytes as compared with normal cells, by a fall in the glycogen labile fraction (from 85 to 53 % of the total glycogen) as well as by decreases in the activities of glycogen phosphorylase and glucose-6-phosphatase by 25 and 82% respectively. The structural rehabilitation occurred faster and more completely at the cellular level than at the tissue level. Functional variables of the cirrhotic liver tissue also recovered, after cessation of poisoning, faster and more completely than the liver structure at the tissue level: glycogen levels in hepatocytes fell dramatically, the labile: stable glycogen fraction ratio recovered completely, and the activity of glycogen phosphorylase rose to the level characteristic of the normal liver. Use of the high-carbohydrate diet promoted a somewhat faster and more complete recovery of hepatic structure and function.

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