[Zajdela hepatoma cells cultured in vitro].

Two continuous cell lines, monolayer (ZH-ad) and suspension (ZH-fl), which doffer in the level of cell differentiation and tumorigenicity, were obtained from explants of ascitic Zajdela hepatoma. Using tumor-specific rabbit immune serum tumor-associated antigens were detected in the fraction of plasma membrane of ZH-fl cells, synthesis of that was reduced or suppressed in ZH-ad cells. Intraperitoneal injection of ZH-fl cells as few as 0.5 - 10(6) cells/rat was enough for development of ascites tumor, while minimal dose for ZH-ad cells increase to 20 - 10(6) cells. Three types of generated clones were revealed by means of clonogenic analysis of ZH-fl cells: nonadhesive sphere colonies and two types of monolayer clones ranging in proliferative potential, shape of colonies and cell composition. When the spherical colonies had reached a critical size they disintegrated with dissociation of single cells or islets of various sizes, part of which attached to the plate to form a monolayer. Three clonal cell lines were obtained: IC - as a result of expansion of sphere clone cells, 4G and 10E - from monolayer clones. Our results demonstrate a clonogenic origin of multicellular islets of ascetic hepatoma Zajdela.

[Immunomodulating effect of cyclophosphamide on cytotoxic activity of rats and mice splenocytes].

This study examines the immunomodulating effect of cytostatic drug--cyclophosphamide (Cy)--on natural cytotoxic activity of rats and mice splenocytes. The cytotoxicity of the effector cells against the confluent monolayer cell lines of rat hepatoma Zajdela and HTC and mice hepatoma MH-22a was estimated by means the morphometric analysis. It was shown, that 48 h after single intraperitoneal injection of Cy produced a immunomodulating effect on the activity of splenocytes--suppressor action on cells of Zajdela hepatoma and immunopotentiating action on the target cells of HTC and MH-22a hepatomas. The possible mechanisms of immunopotentiating effect of Cy are discussed.

[The morphometric analysis of cytotoxical action of rats and mice splenocytes against confluent monolayer cell lines of hepatomas].

The present study was aimed to examine the possibility to use of the morphometric analysis for estimation of the total natural cytotoxic activity of rat and mice C3HA splenocytes against the cultured target cells which formed confluent monolayers. By means of this method we have revealed that two rat monolayer hepatoma cell lines -- HTC and Zajdela -- were sensitive to cytolysis mediated by rat effector cells, but not splenocytes of C3HA mice. The mild pretreatment with 0.5% paraformaldehyde of the rat splenocytes produced a significant decrease only in the cytotoxic activity against the target cells line Zajdela and don't affect the lysis of the other target HTC cells. These results suggest that the natural cytotoxic rat cells may mediate their lytic functions toward tested target lines by different ways. In the case of HTC cells as the targets the effectors induce death receptor-mediated apoptosis, as to target cells Zajdela they deliver lethal hit by perforin-granzyme exocytosis mechanism. The cultured cell monolayers of mice hepatoma -- MH-22a and BWTG3 -- cells showed under conditions of our experiments the resistance to cytolysis by homological effector cells; however, the hepatoma MH-22a cells were susceptible to killing mediated by rat cytotoxic splenocytes.

[Investigation of the surface heteroorganic antigens of rat hepatoma cells involved in process of cell proliferation].

The investigation of antigenic diversion of hepatoma cells resulting from the expression of heteroorganic kidney antigens has been continued. Tumor-associated heteroorganic antigens 110-115 and 125-130 kDa were detected by immunoserum of narrow specificity in fractions of plasmatic membranes of cells of rat ascitic hepatoma Zajdela and cultured hepatoma HTC; the antigen 75-80 kDa was revealed only for hepatoma Zajdela cells. It has been shown by methods of radioisotope analysis and flow DNA-cytometry that heteroorganic antigens 110-130 kDa can be involved in process of cell proliferation.

[Comparative investigation of antigens associated with plasmatic membranes of rat hepatoma and myogenic cells using anti-kidney serum].

The investigation of antigenic diversion of tumor cells resulting from the expression of heteroorganic antigens has been continued. Tumor-associated heteroorganic antigens with mol. weight 200-210 kDa (identified before as laminin), 105-130, 75-80 and 43 kDa were detected by anti-kidney serum in fractions of plasmatic membranes of cells of rat ascitic Zajdela hepatoma and cultured HTC hepatoma; the antigen 43 kDa was isolated on immunosorbent and identified by mass spectrometry as beta-actin. Anti-kidney serum revealed laminin in fractions of plasmatic membranes of cultured L8 and L6J1 myoblasts, and L6J1 myotubes; apparently, synthesis of laminin by hepatoma and myogenic cells is not connected with their proliferative activity. Besides, anti-kidney serum detected components 38, 42, 44, 48, 62, 78 and 120 kDa, expression of which on myogenic cells surface might be consequence of active cell proliferation and (or) differentiation.

[Detection and identification of a tumor-associated heteroorganic antigen of Zajdela hepatoma in non-histone proteins of chromatin].

By polyacrylamide gel electrophoresis, a phosphoprotein with mol. weight of 42 kDa was detected in non-histone proteins (NHP) of chromatin of Zajdela ascitic hepatoma cells eluted from phosphocellulose with 0.4-0.5 M NaCl. A protein of the same mol. weight is present in narrow fractions of rat kidney chromatin, but is absent in rat liver. It is suggested that the revealed protein corresponds to the tumor-associated heteroorganic NHP antigen detected earlier in NHP chromatin of rat tumor cells. By MALDI mass spectrometry, this phosphoprotein was identified as ERK2/mitogen-activated protein kinase.

[Effect of narrow fractions of chromatin non-histone proteins on the expression of membrane tumor-associated antigen MA-50 and phosphorylation of proteins of cultured rat hepatocytes]. / Vliianie uzkikh fraktsii negistonovykh belkov khromatina na ékspressiiu membrannogo opukholevoassotsiirovannogo antigena MA-50 i fosfolirovanie belkov kul'tiviruemykh gepatotsitov krysy.

As earlier reported, the main component of narrow fractions of chromosomal non-histone proteins (NHP) of kidney and of Zaidel hepatoma cells has its own protein kinase activity, and is identified as a heteroorgan NHP-antigen, which is intrinsic to the definite renal tissue and absent in the liver. Effects of narrow fractions of kidney and Zaidel hepatoma NHP on biosynthetic processes and sizes of hepatocytes were studied in vitro. It has been shown that as a result of a 5 h incubation of rat hepatocytes with a narrow fraction of renal NHP the proportion of small hepatocytes increases approximately by 12% as compared with that of cells cultivated without NHP. Besides, binding of organ-specific anti-kidney immune serum with a small hepatocyte population rises by more than 20%, which results from the expression of tumor-associated heteroorgan kidney-specific antigen on the hepatocyte surface. According to immunoprecipitation and subsequent electrophoresis, the molecular mass of a membrane heteroorgan antigen on the surface of hepatocytes amounts approximately to 65 kDa, and an active phosphorylation of cellular proteins takes place. The same effect on hepatocytes is produced by a narrow NHP fraction of chromatin of Zaidel hepatoma cells, whereas no phosphorylation is observed in the presence of liver NHP as well as in the absence of NHP. It is suggested that the heteroorgan NHP-antigen induces biosynthetic processes including synthesis of membrane tumorassociated antigen on the surface of hepatocytes cultivated in vitro by activation of cellular protein phosphorylation, which can lead to changes in size of cultivated cells.

[The detection of membrane tumor-associated antigens of Zajdela's hepatoma on the surface of cultured rat cells]. / Vyiavlenie membrannykh opukholeassotsiirovannykh antigenov gepatomy Zaidela na poverkhnosti kul'tiviruemykh kletok krys.

Membrane tumor-associated antigens of the rat hepatoma Zajdela were revealed using immune serum against cell membranes of this hepatoma. By means of SDS-polyacrylamide gel electrophoresis and the following immunoblotting, it was shown that the membrane tumor-associated antigens of hepatoma Zajdela consisted, at least, of 10 components with molecular weights near 22, 25, 31, 33, 42, 46, 56, 65, 96 and 180 kDa. Specific binding of the immune serum with antigens of cultured hepatomas 27 and HTC cell membranes, of myogenic cells and rat kidney fibroblasts may be suggestive of the expression of some tumor-associated hepatoma Zajdela antigens on the surface of these cultured cells.

[The membrane hetero-organic antigens of tumors of hepatocellular and myogenic origins]. / Membrannye geteroorgannye antigeny opukholei gepatotselliuliarnogo i miogennogo proiskhozhdeniia.

Cell-surface antigens of some tumors and homologous definitive tissues were investigated with organospecific immunoserum against rat kidney membranes using methods of immunofluorescence and enzyme immunoassay. Myogenic cells were also tested to resolve the role of the membrane hetero-organic antigens in the process of proliferation. Membrane hetero-organic antigens, commonly attributed to definitive kidney tissue, were found on the cell surface of rat rhabdomyosarcoma RA-2 and cultured cells of rat hepatomas HTC and 27. However, hetero-organic antigens on the surface of active proliferating myogenic cells were not found. It is concluded that membrane hetero-organic antigens, usually attributed to definitive kidney tissue, represent one of characteristic manifestations of neoplastic cell transformation rather than results of intensive proliferation of the cells.

[The isolation and characteristics of hetero-organic membrane antigens of kidney origin associated with Zajdela's hepatoma]. / Vydelenie i kharakteristika membrannykh geteroorgannykh antigenov pochechnoi prirody, assotsiirovannykh s gepatomoi Zaidela.

A hetero-organic antigen of kidney origin from cell membranes of the Zajdela ascitic hepatoma, and organospecific kidney antigens from cell membranes of kidney were purified using affinity chromatography with antibodies from organospecific antikidney serum immobilized with the CNBr-sepharose. By means of SDS-polyacrylamide gel electrophoresis it was shown that organospecific kidney antigens consisted of at least 6 components, but only one major band, with molecular weight near 50 kDa corresponds to a single component identified as a hetero-organic antigen of kidney origin purified from cell membranes of the Zajdela hepatoma.

[Antioxidant activity of high density lipoproteins in vivo]. / Antioksidantnaia aktivnost' lipoproteidov vysokoi plotnosti in vivo.

The paper deals with antioxidant effect of high density lipoproteins (HDL) in vivo. The effect of intravenous injection of large-dose HDL3 (200 mg protein), isolated from human plasma to rabbits with experimental hypercholesterolemia, on the content of primary products of lipid peroxidation in rabbit blood, the correlation between HDL cholesterol level and the content of lipid peroxide products in blood plasma of healthy persons and patients with IHD were studied. Intravenous injection of HDL3 to rabbits with experimental hypercholesterolemia has been shown to lead in 6 hr to a 24-hr significant (p < 0.01) decrease of conjugated dienes and trienes. The existence of negative correlation between HDL-cholesterol level and the content of conjugated dienes in blood plasma of healthy persons (N = 47) and patients with IHD (n = 64) is revealed. Basing on the data obtained conclusion of universal character of protective antiatherogenic effect of HDL is drawn.

[Catabolism of native and modified high-density lipoproteins in rabbits]. / O katabolizme nativnykh i modifitsirovannykh lipoproteidov vysokoi plotnosti v organizme krolika.

Rates of fraction catabolism of rabbit and horse total 125I-high density lipoproteins (HDL) were shown to be similar in rabbits, after intravenous administration, while catabolism of human, dog and, especially, of rat lipoproteins occurred at the higher rate as compared with rabbit HDL. Rabbit HDL containing modified epsilon-aminogroups, or guanidine groups, or carboxyl groups and native HDL were quite similarly eliminated from circulation of healthy animals, whereas the lipoproteins with modified tyrosine residues and, especially, succinated HDL exhibited the highest rate of elimination. Radioactivity of spleen tissue and lymphatic glands was several-fold higher after intravenous administration of succinated homologous 125I-HDL into rabbits as compared with the effect of native homologous 125I-HDL; in kidney, adrenal glands, liver tissue and small intestine the level of radioactivity was analogous after treatment with both homologous native and succinated 125I-HDL. During incubation with mice peritoneal macrophages modified lipoproteins were captured 1.5-fold more effectively as compared with native HDL. The data obtained suggest that the type of HDL catabolism prevailed in rabbits, which did not involve specific cell receptors to apoprotein components of these lipoproteins.

[The rate of elimination of homologous and heterologous native and modified high density lipoproteins from rabbit plasma after their intravenous administration]. / Skorost' éliminatsii gomologichnykh i geterologichnykh nativnykh i modifitsirovannykh lipoproteidov vysokoi plotnosti iz plazmy krovi krolika posle ikh vnutrivennogo vvedeniia.

Rates of catabolism of total fraction of human native high density lipoproteins (HDL) and their subfractions as well as horse and rabbit native and modified HDL were studied after intravenous administration of the HDL into healthy rabbits and the animals with experimental hypercholesterolemia. The following procedures were carried out for production of HDL derivatives: methylation, succination, blocking of Arg residues and of COOH-groups. Rates of catabolism were similar for rabbit and horse total fractions of 125I-HDL, whereas human HDL were catabolized at a slightly higher rates as compared with rabbit lipoproteins. After administration of human total HDL fractions their elimination, estimated by output of alpha-cholesterol (alpha-C), occurred at a higher rate in healthy rabbits as compared with the animals with hypercholesterolemia, whereas output of apoprotein (apo) A-I was similar in both these groups. As HDL are able to exhibit the properties of alpha-C donor in circulation, estimation of apo A-I should be a more reliable index of the HDL content in blood plasma as compared with alpha-C. Chemical derivatives of rabbit HDL were eliminated from circulation of control animals at a rate similar to that of native HDL rate, but exceeding the rate established for succinated HDL. As compared with native HDL all the modified horse HDL were eliminated at the higher rate from the circulation of healthy rabbits. In rabbits with hypercholesterolemia the higher rate of elimination was shown only for succinated and methylated HDL fractions. Succinated HDL were catabolized at the highest rate apparently due to marked negative charge of their molecules. The data obtained suggest that in rabbits HDL are catabolized via pathways which do not involve specific cell receptors.

[Age and dynamics of the chief blood lipid indices among the adult population of Leningrad]. / Vozrastnaia dinamika osnovnykh lipidnykh pokazatelei krovi sredi vzroslogo naseleniia Leningrada.

Variations in the blood levels of total cholesterol (C), triglycerides, low and high density lipoprotein cholesterol ( LDLPC , HDLPC ) and atherogenicity ratio were examined over time in 4841 men and 2323 women living in Leningrad. The mean values of the parameters studied were established for different age groups. Considerable differences were revealed in the blood lipid profile in men versus women. Higher levels of HDLPC and lower concentrations of LDLPC in women under 50 as compared with age-matched men account for a later development and milder course of coronary heart disease in premenopausal women.

[The rate of elimination of heterologous native and modified high-density lipoproteins from rabbit blood plasma after their intravenous administration]. / Skorost' éliminatsii geterologichnykh nativnykh i modifitsirovannykh lipoproteidov vysokoi plotnosti iz plazmy krovi krolika posle ikh vnutrivennogo vvedeniia.

Native and modified horse LPHD (methylated, succinylated, with blocked Arg-residues and COOH-groups) were administered intravenously (400 mg by protein) into healthy rabbits and into animals with hypercholesterolemia. Concentration of the modified LPHD decreased much more distinct in blood plasma of healthy rabbits as compared with native LPHD. The same results were obtained in rabbits with hypercholesterolemia after administration of methylated and succinylated LPHD. The higher rate of elimination of the modified LPHD appears to occur due to their phagocytosis by macrophages. The data obtained suggest that catabolism of LPHD in rabbits, contrary to LPLD catabolism, did not involve specific cell receptors.

[Rate of elimination of human high-density lipoproteins after their intravenous administration in rabbits by the loss of alpha- cholesterol and apoprotein A-1]. / Izuchenie skorosti éliminatsii chelovecheskikh lipoproteidov vysokoi plotnosti posle ikh vnutrivennogo vvedeniia krolikam po ubyli al'fa-kholesterina i apoproteina A-1.

Native HDL, HDL2 or HDL3, isolated from donor plasma were intravenously administered at a large dose (100 mg HDL cholesterol) to healthy rabbits and rabbits with experimental hypercholesterolemia. The elimination rate of human HDL was studied on the basis of alpha-cholesterol (alpha-Ch) and apoprotein (apo) A-I determinations in the plasma of rabbits. Administration of HDL or their subclasses at a large dose with the following determination of alpha-Ch or apo A-I enabled to avoid the use of radioactive label and all the methodological errors connected with the latter. After administration of HDL, HDL2 and HDL3 their elimination according to alpha-Ch determination occurred at the higher rate as compared with apo A-I. Elimination of the total HDL fraction according to alpha-Ch determination was higher in healthy rabbits than in animals with hypercholesterolemia while the elimination estimated by the apo A-I determination was similar in both groups of animals. These data suggest that HDL may characterize the Ch-donor properties. Apo A-I as compared with alpha-Ch was a more accurate indicator of HDL concentration in blood plasma.

[Participation of lecithin-cholesterol-acyltransferase in the redistribution of high density lipoprotein subfractions in the blood of newborn infants]. / Ob uchastii letsitin-kholesterin-atsiltransferazy v pereraspredelenii podfraktsii lipoproteidov vysokoi plotnosti v krovi novorozhdennykh.

Evidence was obtained in vitro for the participation of lecithin-cholesterol acyl transferase in redistribution of subfractions of high density lipoproteins (HDLP) in blood plasma of newborn children. Content of some HDLP subfractions (HDLP 2c and HDLP 2b) was decreased and content of the other subfractions (HDLP 2a) was increased after incubation of blood plasma of the newborn children with lecithin-cholesterol acyl transferase preparation purified 100-fold.

[Triglyceride, total cholesterol and lipoprotein fraction cholesterol levels in the blood plasma of elderly and long-lived persons in the Abkhazian SSSR]. / Uroven' triglitseridov, obshchego kholesterina i kholesterina lipoproteidnykh fraktsii v plazme krovi liudei starcheskogo vozrasta i dolgozhitelei Abkhazskoi ASSR.

The results of examination of 21 males and 30 females of the category of elderly and long-lived persons (81--106 years old) indicate the low content in the blood plasma of total cholesterol (173 mg/100 ml), beta-lipoprotein cholesterol (106 mg/100 ml), pre-beta-lipoprotein cholesterol (18 mg/100 ml), and triglycerides (91 mg/100 ml). The average content of these lipid complexes was lower in males than in females. The low concentration of beta- and pre-beta-lipoprotein cholesterol and the large portion of alpha-lipoprotein cholesterol content in relation to the content of total cholesterol in blood plasma are evidence of a favourable proportion of atherogenous and non-atherogenous classes of lipoproteins in blood plasma of elderly and long-lived persons, which is evidently one of the causes of the lower incidence of ischemic heart disease among them and their high longevity.