[The cellular apoptosis of murine BW5147 thymoma during cold shock]. / Apoptoz kletok timomy myshi BW5147 pri kholodovom shoke.

The mode of T-lymphoma cell death induced by cold shock was studied. The rewarming of cells at 37 degrees C following a brief period of cold (0 degrees C) resulted in internucleosomal DNA fragmentation. The cells underwent cold shock-mediated apoptosis only at a reduced (2%) serum concentration. The apoptosis was not blocked by macromolecular synthesis inhibitors such as cycloheximide and antinomycin D, or by Quin-2. EGTA per se was responsible for the initiation of cell death. Colchicine also induced internucleosomal fragmentation of DNA. Our findings suggest that cold shock induced apoptosis is associated with low temperature mediated disruption of microtubules. The role of Ca2+ and growth factors in cold shock induced cell death is discussed.

[Differentiation, electrically stimulated nuclear motility and ultrastructure of buccal epithelial cells from normal people and psoriatic patients]. / Differentsirovka, élektrostimuliruemaia podvizhnost' iader i ul'trastruktura kletok v soskobakh bukkal'nogo épiteliia v norme i pri psoriaze.

The comparative analysis of cell differentiation, ultrastructure and volt-stimulated cell nuclear motility was made on buccal epithelium scraped from normal persons and psoriatic patients. About 70% of cells in normal epithelium were classified as cells of the 5th differentiation stage. The same percent of cells exhibited the stimulated nuclear motility. In buccal epithelium of psoriatic patients 54% of cells belonged to the 4th differentiation stage, but ultrastructurally they were of the 3-5th differentiation stages. In epithelial cells of psoriatic patients only 25% of cells were classified as the 5th differentiation stage and 34% of cells had nuclear motility. Their percent increased by 60 when 10(-7) M adrenaline was added in vitro. The results allow conclusion that the nuclear motility is characteristic of degraded epithelial cells with defective tonofilamentous cytoskeleton but with retained electrochemical K(+)-potential.

[The role of changes in the cytoplasmic concentration of Ca2+ in dexamethasone-induced thymocyte death]. / Rol' izmenenii tsitoplazmaticheskoi kontsentratsii Ca2+ v indutsiruemoi deksametazonom gibeli timotsitov.

The putative role of changes in cytosolic Ca2+ concentration ([Ca2+]i) in the dexamethasone (DM) induced thymocyte death was investigated. Incubation of rat thymocytes with 10(-7) M DM for different time intervals from 0.1 to 8 h did not change the basal [Ca2+]i level ca 100 nM as measured with Ca(2+)-fluorescent probe Quin-2. Ca2+ influx measured by the rate of 45Ca2+ uptake was also just the same in DM treated and control cells. At the same time a 6-8 h incubation of cell suspension with 10(-7) M DM results in significant increase in DNA fragmentation and pyknosis, and a 24 h incubation is associated with the decrease in the percentage of cells not staining with Trypan blue. Thus, the results obtained indicate that 10(-7) M DM induces thymocyte death without any significant and constant [Ca2+]i rise during the first 8 h after hormone application.

[Study of the calmodulin-dependent regulation of calcium adenosine triphosphatase of erythrocyte membranes in patients with ischemic heart disease]. / Issledovanie kal'modulinzavisimoi reguliatsii Ca-ATFazy membran éritrotsitov bol'nykh ishemicheskoi bolezn'iu serdtsa.

The inhibitor calmodulin (R 24571) was examined for effects on the activity of red blood cell Ca-ATPases in patients with coronary heart disease during the treatment with nitrates, beta-blockers and calcium antagonists. The maximum activity of Ca-ATPase was measured in the erythrocytes perforated with saponine in the presence of endogenous regulators at a concentration of Ca2+ of 3-5 microM. Patients with high and low Ca-ATPase activity were identified. In the control group R24571 failed to affect Ca-ATPase activity. In patients, the calmodulin inhibitor caused both Ca-ATPase activation and inhibition. The effects of R 24571 correlated with the severity of the patients' condition. In effective therapy, the action of the calmodulin inhibitor became lower on Ca-ATPase activity. It was concluded that there was Ca-ATPase regulation imbalance in patients with coronary heart diseases.

[The evaluation of the role of endogenous Ca-dependent regulators and protein kinases in activating and inhibiting ion-transport ATPases]. / Otsenka roli éndogennykh Ca-zavisimykh reguliatorov i proteinkinaz v aktivatsii i ingibirovanii iontransportnykh ATFaz.

The data on hormonal regulation of ATP-driving ion pumps are contradictory depending on the object used: whether native cells or isolated membranes. To eliminate this contrariety, we studied the ion transporting ATPases in saponin-permeabilized cells in the presence of all endogenous regulators. In permeabilized erythrocytes we obtained the presence of Ca(2+)-dependent activation of Ca(2+)-ATPase by factor(s) not affected by calmodulin antagonist R24571. We obtained also Ca(2+)-dependent activation and inhibition of Na+,K(+)-ATPase. At a concentration of Mg(2+)-ions corresponding to the intracellular level (370 microM), the 0.5-0.7 microM Ca(2+)-activated Na+,K(+)-ATPase (up to 3-fold), whereas the 1-5 microM Ca2+ inhibited it. The cyclic AMP (10(-5) M) inhibited or eliminated Ca(2+)-dependent activation. The decrease in Mg(2+)-ion concentration to 50 microM eliminated the activation and strengthened the inhibition, which reached 100% at the 1-2 microM Ca2+ concentration. The washing of membranes with EGTA eliminated Ca2+ effects on Na+,K(+)-ATPase. These data suggest that the ion-transporting ATPases are activated or inhibited by Ca(2+)-dependent regulators whose activities may be changed by protein kinase catalysed phosphorylation.

[Characteristics of adenosine triphosphatase activity in carp erythrocytes treated with saponin]. / Osobennosti aktivnosti adenozintrifosfataz v éritrotsitakh karpa, obrabotannykh saponinom.

The activities of Ca-ATPase and Na,K-ATPase in saponin-treated erythrocytes of man, rat and carp were compared. It was shown that at free calcium concentrations lower than 1 microM the activity of Ca-ATPase in carp erythrocytes was by one order of magnitude lower than in rat erythrocytes and 3-4 times lower than in human red blood cells. At [Ca2+] = 0.4 microM the activities of Na,K-ATPase in all species under study were essentially the same. The increase in Ca2+ concentration up to 1 microM resulted in a 2-5-fold activation of Na,K-ATPase in rat and carp erythrocytes, respectively. In all cases studied a further elevation of free calcium concentration was accompanied by a decline of the Na,K-ATPase activity. It was shown that the Pi content in carp erythrocytes is 5-6 times as high as that in mammalian cells. This circumstance is a considerable obstacle to a detailed analysis of mechanisms of ATPase activity regulation in carp erythrocytes by methods used for determination of inorganic phosphate production.

[Calcium-transporting system of erythrocytes in psoriasis]. / Kal'tsii-transportiruiushchie sistemy v éritrotsitakh pri psoriaze.

The activity of Ca-ATPase and permeability of erythrocyte membrane for calcium in patients with psoriasis were studied with the aim to reveal disturbances in the calcium membrane transport under psoriasis. In the presence of endogenic activators the mean values of the maximal Ca-ATPase activity of erythrocyte membranes in patients with psoriasis and in healthy people have no essential differences and make up 264 +/- 12 and 244 +/- 10 mumol P/1 cells per 1 min, respectively. The rate of 45Ca accumulation in erythrocytes under inhibition of Ca-ATPase in patients suffering from psoriasis is by 64% higher than in healthy people. The data obtained along with the previously revealed changes in the calcium metabolism in patients with psoriasis make it possible to suppose the presence of the system disturbance of the calcium membrane transport, in particular an increase in the plasma membrane permeability for cells of different types. Such a disturbance may distort a regulatory (messenger) function of calcium ions in the processes of proliferation, differentiation, functional activity and death of different cell types.

[Permeability for 45Ca and Ca-ATPase activity in erythrocyte membranes of patients with psoriasis]. / Izuchenie pronitsaemosti dlia 45Ca i aktivnosti Ca-ATFazy membran éritrotsitov bol'nykh psoriazom.

Accumulation of 45Ca in erythrocytes was 1.6-fold higher in presence of vanadate in patients with psoriasis as compared with healthy persons. This difference was maintained within 24 hrs of the heparinized blood storage, although penetration of Ca2+ through erythrocyte membranes was increased by about 67% both in patients and in healthy persons. Maximal activity of Ca2(+)-ATPase in erythrocyte membranes, measured in presence of endogenous regulators, was near normal values in the majority of the patients (15-300 microM P/L er. min) and above normal values--in 18% of the patients (320-420 microM P/L er. min). The data obtained suggest that systemic impairments of membrane transport of Ca2+ are of importance for pathogenesis of psoriasis.

[Assessment of the role of endogenous regulators in the activation of Ca-ATPase in erythrocyte membranes]. / Otsenka roli éndogennykh reguliatorov v aktivatsii Ca-ATPazy membran éritrotsitov.

The contribution of calmodulin and protein kinases A or C to the activation of membrane Ca-ATPase was studied on saponin-permeabilized rat erythrocytes. In the presence of all endogenous regulators, the dependence of the Ca-ATPase activity of Ca2+ concentration was described by a bell-shaped curve with a maximum at 2-5 microM Ca2+; K0.5 = 0.43 microM Ca2+. Washing of erythrocyte membranes with 5-10 microM Ca2+ maintained up to 75% of the ATPase activity, while washing with EGTA (2 mM) decreased the activity, on the average, 5-fold, and increased K0.5 up to 0.54-0.6 microM Ca2+. An addition of an EGTA extract to washed membranes restored up to 75% of the original ATPase activity, while calmodulin restored about 40% of the original Ca-ATPase activity and decreased K0.5 to 0.23-0.3 microM Ca2+. The calmodulin inhibitor R24571 failed to alter the Ca-ATPase activity in permeabilized erythrocytes but slightly diminished it in reconstituted membranes. The protein kinase C inhibitors H7 and polymyxin increased the Ca-ATPase activity in permeabilized red cells and suppressed it in reconstituted membranes. The data obtained suggest that in native red cell membranes Ca-ATPase is activated by regulator(s) dependent on Ca2+ and protein kinase which are other than calmodulin.

[Does calmodulin participate in the regulation of the Ca-pump of erythrocytes in vivo?]. / Uchastvuet li kal'modulin v reguliatsii aktivnosti Ca-nasosa v éritrotsitakh in vivo?

Using a highly effective chelator of Ca2+ and 45Ca, the concentration of Cai2+ in human and rat erythrocytes was measured both at normal and accelerated Ca2+ influx into the cells. No effect of the calmodulin-dependent reaction inhibitor R24571 was observed. The Ca-ATPase from saponin-treated erythrocytes was characterized by a high affinity for Ca2+ (K 0.5-0.7 microM). This value is 2-3 times as low as that for Ca2+ concentration causing a 50% increase of the Ca-ATPase activity in erythrocyte ghosts obtained during hypoosmotic hemolysis. The Ca-ATPase activity in saponin-treated erythrocytes did not change either under the effect of calmodulin or by R24571. It was assumed that calmodulin did not participate in the regulation of the Ca2+-pump operation in erythrocytes in vivo.

[Cytochemical methods of detecting the ultrastructural localization of calcium]. / Tsitokhimicheskie metody vyiavleniia ul'trastrukturnoi lokalizatsii kal'tsiia.

Conditions and potentialities of electron-cytochemical techniques for calcium detection are analysed in terms of current evidence on the role of membranes in sequestration of intracellular calcium pools. In most cases these conditions did not allow to preserve a native localization of calcium because the lability of calcium pools enclosed within membranes and the action of electron microscopic fixatives on the membrane permeability to Ca2+ and Ca-precipitating agents were not taken into account. Considering these factors it is essential that both the fixator and Ca-precipitating agent could diffuse through membranes simultaneously. The modes to ensure this essential condition as well as the reasons and ways to avoid artifacts in cytochemical studies are given.

[Fixation of early ascarid embryos for electron microscopic research]. / Fiksatsiia rannikh émbrionov askaridy dlia élektronno-mikrosko-picheskikh issledovanii.

Ascaris embryos represent a classical object in embryology, but their ultrastructure has not been so far studied because their sheets are not permeable to fixatives used for electron microscopy. Thus, the fixation with glutaraldehyde for 24 hours followed by a 24 hour OsO4-fixation led to osmification of 1% embryos. The osmification of 100% embryos was achieved after addition of detergents, sodium dodecylsulfate or Triton X-100 to aldehyde fixative. The best fixation was povided using sodium dodecylsulfate judging from ultrastructure preservation.

[Age-related characteristics of the metabolism of fatty acid components of nuclear phospholipids]. / Vozrastnye osobennosti obmena zhirnokislotnykh komponentov iadernykh fosfolipidov.

The metabolism of liver nuclear phospholipid acyl components of rats of various age was studied in vitro. It was found that the activity of phospholipases A1 and A2 in the nuclei sharply increased in animals aged 1-3 months, showing a decrease in 12- and 24-month-old animals. The incorporation of labeled arachidonic acid into nuclear phospholipids remained practically unchanged thereby. The age-specific fluctuations in the activity of nuclear phospholipids A1 and A2 may be one of possible reasons of changes in the fatty acid composition of nuclear lipids during ontogenesis.

[Intracellular localization and possible pathways of transcellular calcium transport in the cells of the proximal kidney tubules]. / Vnutrikletochnaia lokalizatsiia i vozmozhnye puti transkletochnogo transporta kal'tsiia v kletkakh proksimal'nykh kanal'tsev pochki.

Cytochemical and ultrastructural studies of rat proximal tubule cells were carried out to elucidate possible ways of transcellular Ca2+-transfer. The bulk of cellular calcium was found in mitochondria. Calcium was also revealed in some pinocytic vesicles, in cisterns of the Golgi complex and of the smooth endoplasmic reticulum. The sections made parallel to apical-basal axis of cells showed that mitochondria stretch continuously from the apical to the basal plasma membrane. These data suggest that mitochondria may serve as conductors of Ca2+-fluxes from the apical to the basal plasma membranes through the proximal tubule cells.

[Isolation of carotenoid-containing subcellular structures from mollusk nerve tissue]. / Vydelenie karotinoidsoderzhashchikh subkletochnykh struktur iz nervnoi tkani molliuska

A subcellular fraction with a high share of carotenoids (about 150 mkg/mg of protein) was obtained from the nerve tissue of Lymnaea stagnalis, the fractionation being made by sucrose density gradient centrifugation. The quantity of carotenoids extracted from fractions was estimated spectrophotometrically. The electron microscope observations demonstrated the presence of structures analogous to fraction components in the mollusc neurones and similar to some kinds of plant chromplasts (carotenoidplasts).