[Ultrastructural study of liver cells from rooks living in ecologically unfavorable areas].

The ultrastructure of liver cells was studied in rooks (Corvus frugilegus) living in radioactive and chemical contamination areas. The ultrastructure of liver cells from rook as well as jackdaw (Corvus monedula) and hooded crow (Corvus cornix) (Corvidae family) from a conventionally clean area was studied as control. Control hepatocytes proved to contain a great number of mitochondria, many of which were swollen and had clear matrix and disorganized cristae. The cristae nearly lacked glycogen and had abundant lipid droplets, which often tightly contacted mitochondria. The cytoplasm of hepatocytes in birds from both ecologically unfavorable areas had numerous mitochondria with the same ultrastructure. In contrast to control, the hepatocyte cytoplasm: (1) contained a lot of glycogen; (2) there were many lipid droplets, which directly contacted glycogen granules; and (3) had more abundant peroxisomes. In addition to normal erythrocytes, the sinusoids contained erythrocytes with mitochondria, vesicles, and lipid droplets in their cytoplasm. Analysis of many micrographs of lipid droplets contacting glycogen granules, mitochondria, peroxisomes, and cisterns of smooth endoplasmic reticulum allowed us to propose that glycogen is synthesized via gluconeogenesis from glycerol and products of fatty acid oxidation in the liver cell cytoplasm of rooks from ecologically unfavorable areas as distinct from control.

[Erythrophagocytosis and pigment cells of the amphibian liver]. / Eritrofagotsitoz i pigmentnye kletki pecheni amfibii.

The ultrastructure of Kupffer liver cells of adult frogs collected in winter and Kupffer cells during amphibian metamorphosis when larval red cells are replaced by adult red cells were investigated. It was revealed that Kupffer cells of the animals investigated had very large size and consisted of either the whole senescent erythrocyte or many phagosomes with small electron dense granules resembling ferritin. Phagosomes are oriented among numerous vesicular and vermiform profiles of agranular endoplasmic reticulum and big Golgi complex. Comparing our morphologic evidence with data of the literature that granules of melanin are synthesized and localized in frog liver Kupffer cells, we came to conclusion that pigment cells were formed as a result of erythrophagocytosis and therefore they were the depo of catabolism products. The comparison of functions of melano-macrophage centers of fish liver and of pigment cells of amphibia liver were discussed.

[Ultrastructure of liver cells of shrews]. / Ultrastruktura kletok pecheni burozubki.

It was established that the hepatocytes of least shrew (Sorex minutissimus) contained 1-2 nucleus with wide nuclear pores and big nucleolus. There are abundant mitochondria with numerous crists in their matrix (many organelles were divided along the crists). Each mitochondrion was surrounded by the cistern of granular endoplasmic reticulum. The ultrastructure of Golgi complex (1-2 flat cisterns, small vesicles] indicated that the bile was secreted often, by small portions, that was the adaptation to repeated fractional feeding. There were many peroxisomes in the cytoplasm of hepatocytes. Lipid droplets were absent, glycogen granules were not at all hepatocytes. Sinusoidal cells had the usual structure. All sinusoids were open and consisted of the erythrocytes, fragments of hepatocyte cytoplasm and myelin figures in its lumen.

[The hepatocyte ultrastructure of the Sevan trout (Salmo ischchan gegarkuni Kessel) in ontogeny]. / Ul'trastruktura gepatotsitov sevanskoi foreli (Salmo ischchan gegarkuni Kessel) v ontogeneze.

Hepatocytes of Lake Sevan Salmo were examined at several stages in their life cycles which are different from the point of view of the manner of feeding. Salmo were reared at the fish farm, they were fed with the yolk of the chick eggs. It was revealed that hepatocytes of larva, which was sampled immediately after hatching (endogenous feeding) intensively synthesized the proteins; accumulated and secreted the bile product stored glycogen and lipids. The ultrastructure of larva hepatocytes changed on the 5th and 10th day after larva began to accept food (mixed feeding--endogenous and exogenous). Golgi complex became bigger, glycogen disappeared, lipid droplets became smaller (on the 5th day) and disappeared completely (on the 10th day). Morphological differentiation finishes during the fingerling period (exogenous feeding). Cisternae of granular endoplasmic reticulum (GER) and mitochondria are arranged around nucleus, near bile canaliculus and sinusoids. Big areas of glycogen lie between the organelles. Relative volumes of GER, mitochondria, glycogen increased, but the relative volume of Golgi complex diminished.

[Destructive and restorative processes of the liver in rats under intensive physical loading]. / Destruktivnye i vosstanovitel'nye protsessy v pecheni krys pri intensivnoi fizicheskoi nagruzke.

The ultrastructure of rat liver cells after running exercise was investigated. When rats were trained for a month and sacrificed immediately after the last exercise it was revealed that the number of liver cells mitochondria increased, but many of them had alterations: mitochondria became swollen, had lucid matrix. There were some variations in degree of alterations between different mitochondria: a) in the same hepatocyte, b) in different hepatocytes of the same animal, that was connected with individual sensitivity of organelles on the levels of the cell and of the organ. Rough endoplasmic reticulum bore few ribosomes. Glycogen was absent. There were abundant vesicles of smooth endoplasmic reticulum, autophagic vacuoles and peroxisomes in the liver cell cytoplasm. Adaptation of rat liver to the exercise programme becomes evident by 1.5 month of exercise. Mitochondria and rough endoplasmic reticulum were numerous and of normal structure. There were many peroxisomes and glycogen granules in the cytoplasm of hepatocyte. The presence of large autophagic vacuoles in the cytoplasm of some hepatocytes were obviously connected with more rapid destruction of some organelles, than in control.

[Unusual structure of the biliary system in the liver of the grass carp and the silver carp]. / Neobychnoe stroenie zhelchevydelitel'noi sistemy v pecheni belogo amura i belogo tolstolobika.

It is known that the bile canaliculus in the liver of almost all vertebrates is made up of membranes of two or more adjacent liver cells. Studying the liver cell ultrastructure of lasting and fed grass carp and silver carp, it was demonstrated that a bile canaliculus is formed by deep invagination of a cell membrane of one hepatocyte. The membrane forms microvilli along the bile canaliculus. The bile canaliculus is seen in the centre of liver cell cytoplasm on the cross section and stretches from the centre of the liver cell cytoplasm to the cell membrane on the longitudinal section. The bile canaliculus is connected with a small duct cell, which is distinct from a liver cell in its small size, little amount of cell organelles and the presence of cytoplasmic filaments. The terminal part of the biliary tract consists of one liver cell and one bile duct cell. The part of the tract adjacent to the terminal one is composed of two or three small bile duct cells devoid of basal membrane. Thus, the liver parenchyma is constituted of a net of numerous bile ducts. In the portal tract, there is a large bile duct, consisting of 12-13 bile duct cells, surrounded by basal membrane and connective tissue cells.

[Appearance of clasmatosis in the normal and pathological liver]. / Iavlenie klazmatoza v pecheni v norme i pri patologii.

It was established that clasmatosis of cytoplasmic fragments toward sinusoids occurred under normal physiological conditions (embryogenesis of chick liver, the liver of starved grass carp and silver carp) and pathological conditions (disturbance of rat hepato-intestinal circulation). The clasmosomes of rat and chick liver cells contained free ribosomes and small vesicles while those in the liver of starved fish consisted of glycogen. It was also shown that mitochondria with the signs of complete clasmatosis appeared in the hepatocyte cytoplasm immediately after the beginning of intensive bile secretion to the bile canaliculus (in liver cells of rat and chick embryo and in those of frogs after complete metamorphosis). Such mitochondria were partially disintegrated and were located near the bile canaliculi. It is assumed that clasmatosis of the fragments of the liver cell cytoplasm or mitochondria takes places where it is necessary to rapidly supply the body or cell with some products of metabolism or to remove something from the cell as is the case with erythroblasts, i. e. clasmatosis is one of the mechanisms of the adaptation of the cell and its organelles to changes in the environment.

[Genesis of the Golgi complex]. / K voprosu o geneze kompleksa Gol'dzhi.

In the early period of rat and chicken liver embryogenesis, the Golgi apparatus is formed through the budding of the vesicles from the outer part of the nuclear hepatocyte membrane. In the later period of embryogenesis and after birth, the Golgi apparatus is supplemented with the vesicles that bud from smooth enlarged parts of granular endoplasmic reticulum cisterns. The dimensions of the Golgi apparatus depend on the intensity of hepatocyte functioning.

[Hepatocyte ultrastructure during accumulation and secretion of bile products]. / Ul'trastruktura gepatotsita pri nakoplenii i vydelenii produktov zhelchi.

It has been established that the time course of alterations in the ultrastructure of chick embryo hepatocytes in the course of synthesis, accumulation and secretion of bile products involves 1) an increase in the hepatocytic cytoplasm of the number of small profiles of smooth endoplasmic reticulum with the particles resembling very low electronic density lipids; 2) an abrupt increase in the size of Golgi complex; accumulation of material of different electron density in the enlarged areas of Golgi cisterns; 3) bubbling out of small vesicles and large vacuoles containing material of different electron density from Golgi complex; localization of small vesicles, large vacuoles and mitochondria with translucent matrix about the bile canaliculus; 4) localization of Golgi complex somewhat farther from the bile canaliculus than before; 5) fusing of the membranes of the small vesicles with the bile canalicular membrane thereby producing secretion of bile products an; d clasmatosis of mitochondrial fragments; 6) enlargement of the bile canalicular lumen, accumulation of material of different electron density in the canaliculus.

[Electron microscopic and histochemical characteristics of hepatomas arising during long-term administration of carbon tetrachloride]. / Elektronno-mikroskopicheskaia i gistokhimicheskaia kharakteristika gepatom, voznikaiushchikh pri dlitel'nom vvedenii chetyrekhkhloristogo ugleroda.

Hepatomas arising as a result of prolonged injection of CCl4 consist of cells in which the processes of dystrophy and intracellular regeneration are pronounced to a different degree. In the late stages of development, hepatomas tend to malignancy, exhibiting cells that bear ultrastructural resemblance to the cells of malignant hepatomas. Histological examination revealed high aerobic glycolysis and decreased activity of oxidizing enzymes. Discontinuance of CCl4 injection did not entail normalization of the liver structure. The sinusoidal cells are likely to play an essential role in the development of intralobular liver fibrosis.

[Physiological and reparative regeneration of the mitochondria]. / K voprosu o fiziologicheskoi i reparativnoi regeneratsii mitokhondrii.

The ultrastructure of mitochondria of hepatocytes in normal and pathological conditions was studied. It was shown that the process of regeneration of the ultrastructure of swollen mitochondria with a lucent matrix up to the normal state was completed in hepatocytes of the rat and chick embryos within one day. It was established that one of the ways of intraorganoid regeneration of mitochondria in hepatocytes of chick embryos and of mice after injections of CCl4 twice a week for 5 months was clasmatosis of the destroyed mitochondria fragments and their removal through the partially disintegrated exterior membrane of mitochondria followed by the membrane restoration. The process of mitochondrial regeneration after clasmatosis of its fragments was shown to require two days in the chick embryo hepatocytes.