Impaired synthesis of erythropoietin, glutamine synthetase and metallothionein in the skin of NOD/SCID/gamma(c)(null) and Foxn1 nu/nu mice with misbalanced production of MHC class II complex.

Most skin pathologies are characterized by unbalanced synthesis of major histocompatability complex II (MHC-II) proteins. Healthy skin keratinocytes simultaneously produce large amounts of MHC-II and regeneration-supporting proteins, e.g. erythropoietin (EPO), EPO receptor (EPOR), glutamine synthetase (GS) and metallothionein (MT). To investigate the level of regeneration-supporting proteins in the skin during misbalanced production of MHC-II, skin sections from nonobese diabetic/severe combined immunodeficient (NOD/SCID)/gamma (c) (null) and or Foxn1 nu/nu mice which are a priory known to under- and over-express MHC II, respectively, were used. Double immunofluorescence analysis of NOD/SCID/gamma (c) (null) skin sections showed striking decrease in expression of MHC-II, EPO, GS and MT. In Foxn1 nu/nu mouse skin, GS was strongly expressed in epidermis and in hair follicles (HF), which lacked EPO. In nude mouse skin EPO and MHC-II were over-expressed in dermal fibroblasts and they were completely absent from cortex, channel, medulla and keratinocytes surrounding the HF, suggest a role for EPO in health and pathology of hair follicle. The level of expression of EPO and GS in both mutant mice was confirmed by results of Western blot analyses. Strong immunoresponsiveness of EPOR in the hair channels of NOD/SCID/gamma (c) (null) mouse skin suggests increased requirements of skin cells for EPO and possible benefits of exogenous EPO application during disorders of immune system accompanied by loss MHC-II in skin cells.

Colocalization of three types of intermediate filament proteins in perisinusoidal stellate cells: glial fibrillary acidic protein as a new cellular marker.

The presence and the colocalization of the three intermediate filament proteins, glial fibrillary acidic protein (GFAP) and the marker of mesenchymal liver cells, vimentin, were studied by an immunofluorescence double-labeling technique in cultures of isolated rat perisinusoidal stellate cells (PSC) and hepatocytes, in cocultures of isolated PSC and hepatocytes as well as in cryostat sections of rat liver. GFAP and vimentin immunoreactivities were localized in cultured PSC which were identified by the presence of the cellular marker desmin, another intermediate filament protein, or the stellate morphology to be seen after staining for one of three intermediate filament proteins. Both GFAP and vimentin were strongly expressed in the perinuclear region and the cell processes of cultured PSC. Staining for GFAP highly coincided with that for vimentin or desmin in cultured PSC and with that for vimentin in the liver sections. Desmin-positive cells were always also GFAP-positive. However, of the GFAP-positive cells only an estimated 50% were found desmin-positive. The coexpression of desmin and GFAP in the same cells appear to be unique, since apparently it has not been previously reported for any other cell type. Almost all of the vimentin-positive cells in hepatocyte culture were also expressing GFAP. Since desmin was not found in all of the cultured cells with PSC morphology, GFAP is suggested as a more reliable marker for PSC than desmin.

Stages of activation of hepatic stellate cells: effects of ellagic acid, an inhibiter of liver fibrosis, on their differentiation in culture.

UNLABELLED: To further explore that hepatic stellate cell (HSC) activation results in physiological protection against environmental insult, the profile of differentiation of HSC has been examined upon treatment with ellagic acid (EA), a plant-derived antioxidant that shows multiple protective effects during liver disease. Sparse rat liver cell cultures were grown in media containing EA (3, 6, 30 and 100 microg/ml) and, as controls, without EA, and inspected until day 7 in culture. The cells were double-labelled with antibodies against glial fibrillary acidic protein (GFAP) and smooth muscle alpha-actin (SMAA), marker proteins of quiescent and activated HSC, respectively. In EA-free culture conditions, the quiescent (SMAA-/GFAP+) HSC transiently acquired a semi-activated (SMAA+/GFAP+), phenotype and were further transformed into activated (SMAA+/GFAP-), pleomorphic HSC. Up to a concentration of 30 microg/ml, EA induced an early synthesis of SMAA in all HSC and inhibited their morphologic differentiation and individual growth throughout the culture period. At a concentration of 6 microg/ml, EA supported the semi-activated (SMAA+/GFAP+) phenotype of HSC throughout the culture period, whereas treatment with high EA concentrations (30 microg/ml) resulted in an early loss of GFAP expression. IN CONCLUSION: (i) the uniform response of HSC to EA by mild activation adds functional significance to cellular features preceding the transformation of HSC to myofibroblasts; (ii) the high sensitivity of HSC to EA treatment suggests their involvement in any mechanisms of protection by this antioxidant; (iii) the maintenance of HSC morphology might be one of the factors playing a role in the prevention or slowing down of liver fibrosis; (iv) because the effects of EA are concentration- and time-dependent, an arbitrary usage of this antioxidant is a matter of potential concern; (v) the various patterns of HSC activation observed might correspond to distinct activities of these cells, which, in turn, might lead to different outcomes of liver fibrosis.

Common myofibroblastic features of newborn rat astrocytes and cirrhotic rat liver stellate cells in early cultures and in vivo.

Double-immunolabelling techniques were employed to investigate the distribution of smooth muscle alpha-actin (actin) in glial fibrillary acidic protein (GFAP)-positive cells in rat brain during early postnatal development and maturation and in glial primary culture derived from newborn rat brain. In addition the expression of desmin was studied in the glial primary cultures as a function of the differentiation of the cells. Comparison of the cultured astroglial cells at an early age with hepatic stellate cells derived from CCl4-induced cirrhotic rat liver, revealed features of the astrocytic cytoskeleton characteristic of myofibroblastic cells, i.e., strong expression of both myofibroblastic markers, actin and desmin. In astroglial cells with an initial morphology reminiscent of fibroblasts the non-filamentous perinuclear immunoreaction of GFAP increased with time at the expense of actin and, partially, desmin. GFAP filaments were spread throughout the cytoplasm of the cells which acquired stellate morphology. The alterations in the morphology of the cells and the distribution and intensity of staining for GFAP and actin during the differentiation of astrocytes in culture were similar to those observed in astrocytes during the maturation of the brain. In astrocytes from a newborn brain as well as in cirrhotic hepatic stellate cells, the area of immunoreaction of GFAP was reduced and confined mainly to the nuclear region. In contrast, the cells expressed actin throughout the cytoplasm. These findings may hint at a similar function of these regionally specialized perivascular myofibroblastic cells in a normal brain and diseased liver and at inverse organ-specific functions which the cells fulfill under non-pathological conditions in vivo.

Acquisition of blood--tissue barrier--supporting features by hepatic stellate cells and astrocytes of myofibroblastic phenotype. Inverse dynamics of metallothionein and glial fibrillary acidic protein expression.

A number of similarities between astrocytes and hepatic stellate cells (HSC) rose the question whether or not the protective barrier features of blood-tissue interface may be provided by HSC as well. To test this hypothesis, we investigated the presence of metallothionein (MT), a functional marker of blood--brain barrier, in HSC in situ and in cell culture and compared the results with those obtained with astrocytes. The dynamics of MT expression in cultured astrocytes and HSC was investigated by simultaneous labelling of the cells with a monoclonal antibody (MAb MT) against a lysine-containing epitope of the cadmium-induced monomer of MT-I from rat liver and antiserum against glial fibrillary acidic protein (GFAP). Cell activation was estimated by the presence of smooth muscle alpha-actin (SMAA). In immunoblotting, MAb MT recognized monomeric MT protein and proteins in the 30-kDa range; both bands were pronounced in brain and barely visible in liver homogenates. In situ, MAb MT reacted with very few perivascular cells situated in the parenchyma of the liver. Double immunolabelling of brain slices with MAb MT and antiserum against GFAP showed large areas of brain containing cells expressing both MT and GFAP. However, there were also regions in the brain where the cells produced solely GFAP or MT. In liver cell culture, MT was absent from HSC and hepatocytes in early periods of cultivation, during which the cells maintained their original features; however, MT was expressed strongly in HSC during their activation under prolonged culture conditions. Inversely, in astrocytes MT was expressed during early culturing and disappeared from the cells together with SMAA in late culture when GFAP was upregulated. These results suggest that the acquisition of myofibroblastic features by perivascular cells empowers them to establish a protective blood-tissue permeability barrier. In addition, this study shows that, at least in cell culture, an enrichment of perivascular cells in GFAP results in the disappearance of protective functions.

[Effect of gamma-aminobutyric acid on K+-induced and Ca++-dependent release of H3-noradrenaline from synaptosomes of the meso-diencephalic region of the rat brain]. / Deisvie gamma-aminomaslianoi kisloty na K+-vyzvannoe Ca++-zavisimoe vysvobozhdenie noradrenalina-H3 iz sinaptosoma mezo-diéntsefal'noi oblasti mozga krys.

GABA exerted no effect on H3-NA release from synaptosomes in the presence of 20 mM K+ whereas it considerably reduced the release of H3--NA evoked by 40 mM K+ ions. The omission of Ca++ ions from the superfusion fluid reduced by H3-NA release; on the other hand, GABA in this condition enhanced considerably the release of H3-NA thus exhibiting Ca++-like effect. Thus in the absence of Ca++ or in the presence of its low (1 mM) concentrations the effects of GABA on the H3--NA release from the synaptosomes was reversed.

[The effect of exogenous concentration of chlorine and calcium ions on GABA and bicuculline action on the K+ -induced release of H3-noradrenaline from synaptosomes]. / Vliianie naruzhnoi kontsentratsii ionov khlora i kal'tsiia na deistvie GAMK i bikukullina v K+ -vyzvannom vysvobozhdenii noradrenalina-H3 iz sinaptosom.

Effects of GABA (10(-3) M) and its antagonist bicuculline on K+-evoked release of H3-NA were studied in synaptosomes of rat mesodiencephalic region in the absence of Cl-, Ca2+ ions and in the presence of Ca2+ antagonist Mn2+ ions. K+-evoked release of H3--NA activated by GABA did not change in a Cl--free medium. Bicuculline blocked the activating effect of GABA. Some noticeable activation of K+-evoked release of H3--NA was observed in Cl- and Ca++--free medium. GABA, however, inhibited this process. Under these conditions, K+-evoked release of H3--NA did not occur in the presence of bicuculline. Mn2+ ions blocked GABA- and bicuculline--activated K+--evoked release of H3--NA. Taking into account the opposite effect of GABA on K+-evoked release of H3--NA depending on ionic changes in incubation media, the possibility of Cl- and Ca2+ ions participation in the GABA effect is considered.

[Multiple forms of cathepsin D from the human brain]. / Mnozhestvennye formy katepsina D iz mozga cheloveka.

Six peaks of the endopeptidase activity at pH 3.2 were obtained after isoelectric focusing of soluble fractions of cortex and hypothalamus of the human brain. The molecular weight of these endopeptidases are approximately 50000. All obtained endopeptidases possess almost the same Km and I50 relative to the substrate--pyridoxal globin and specific inhibitor--pepstatin. The studies of the revealed properties show that the endopeptidases are multiple forms of cathepsin D.

Further similarities between astrocytes and perisinusoidal stellate cells of liver (Ito cells): colocalization of desmin and glial fibrillary acidic protein in astroglial primary cultures.

The colocalization of desmin and glial fibrillary acidic protein (GFAP) in astrocytes was inferred from previous studies demonstrating a unique antigenic composition comprising GFAP, desmin and vimentin in perisinusoidal stellate cells (PSC) of liver which share several features with astrocytes. In the present study the colocalization of GFAP and desmin was investigated by double-immunolabeling experiments in 12-day-old rat astroglial primary cultures with antiserum against GFAP and two commercial monoclonal antibodies against desmin, antibodies of clone DEU-10 and clone DEB-5. These antibodies selectively decorated the perisinusoidal stellate cells (PSC) of liver for which desmin is known to be a marker. The results obtained with astroglial cells demonstrate that both GFAP and desmin are coexpressed in morphologically different types, process-bearing and process-lacking astrocytes. The expression of desmin was apparently more pronounced in process-lacking astrocytes and was considerably lower in process-bearing ones. In process-lacking astrocytes, in contrast to filamentous cytoplasmic staining for GFAP, the immunoreactivity for desmin was non-filamentous and was irregularly spread in the perinuclear cytoplasm of the cells, while in process-bearing astrocytes the pattern of staining for desmin was similar to that of GFAP. The variability in the intensity and pattern of staining for desmin in astrocytes might be due to transitional stages of differentiation for part of the cells. This interpretation was supported by the presence of GFAP in the cells weakly expressing smooth muscle alpha-actin and the absence of GFAP in the cells enriched with microfilaments.

[Role of adenine mono- and dinucleotides in ammonia formation in brain tissue]. / Rol' adeninmono- i dinukleotidov v obrazovanii ammiaka v mozgovoi tkani

The investigations carried out have shown that not only AMP but ADP also undergoes direct deamination in both soluble and mitochondrial fractions of rat brain tissue. Deamination of AMP is stimulated by the addition of ATP and the activity of one of the isoenzymes of AMP-aminohydrolase is markedly enhanced by both yeast and brain hexokinase. Activation by hexokinase is mainly due to its SH groups, through which hexokinase reacts with AMP-aminohydrolase, forming, probably, a protein-protein complex in which AMP aminohydrolase activity is considerably increased. Hexokinase does not affect the deamination of ADP and NAD. Further experiments are needed to find out whether the activation of AMP-aminohydrolase is accomplished by hexokinase itself or by an other protein contaminating it. Deamination of NAD, in contrast to AMP and ADP, takes place only in mitochondria and does not occur in the soluble fraction. In mitochondria besides deamination, AMP and ADP undergo intensive dephosphorylation, while the deamination of NAD is not accompanied by an increase of phosphate, i. e. mitochondria lack enzymes which breakdown NAD to mono nucleotides. Our data indicate that the formation of deamino -NAD from NAD and reamination of deamino-NAD by aspartate to NAD by the formation of intermediary NAD-succinate is of greater importance. The formation of the latter and that of deamino-NAD from NAD as well as the presence of preformed deamino-NAD in mitochondria have been demonstrated by Movsessian. The occurrence of these processes in mitochondria and their role in the formation of ammonia from amino acids is of importance in as much as oxaloacetate formation and its conversion to aspartate, which is necessary for the reamination of deamino-NAD, are localized in mitochondria. The main source of the amino nitrogen of aspartate is known to be glutamate, which incorporates the amino nitrogen of most amino acids. alpha-Keto-glutarate, which is necessary for the synthesis of glutamate, is also formed in mitochondria are the most favourable site for the formation of ammonia from amino acids with the participation of pyridine nucleotides. Of the purine mono and dinucleotides studied deamino-NAD is most effective in the formation of ammonia from amino acids in mitochondria since in contrast to purine mono nucleotides, deamino-NAD and NAD are not dephosphorylated in mitochondria. According to some authors the reamination of IMP by aspartate is of importance in the formation of ammonia from amino acids in brain tissue. In our studies, however, IMP was not effective in the formation of ammonia from aspartate in mitochondrial fractions. IDP was found to be more effective. IMP and IDP may probably participate in the formation of ammonia in the soluble fraction, where nucleotidase activity is considerably low.

Glial fibrillary acidic protein as a marker of perisinusoidal stellate cells that can distinguish between the normal and myofibroblast-like phenotypes.

Glial fibrillary acidic protein (GFAP) has recently been shown to provide a marker for normal perisinusoidal stellate cells (PSC) in the liver. However, nothing was known so far about the changes in the intercellular abundancy of GFAP during transformation of PSC into myofibroblasts, a process characterized by marked changes in the expression of elements of the cytoskeleton. In order to address this question, we have used double-labelling immunofluorescence techniques for detecting smooth muscle alpha-actin (SMAA) and the intermediate filament proteins, GFAP, desmin and vimentin, taking advantage of the fact that PSC present in primary cultures of rat hepatocytes proliferate and transform. GFAP and vimentin were expressed in PSC throughout cultivation, while desmin which stained only about half of the PSC in early cultures was expressed in all GFAP-positive cells later on. The intensity of staining for GFAP in PSC transiently increased till the second day of cultivation followed by a decrease. At the 6th day of cultivation, staining for GFAP was seen only in the perinuclear region and as a faint rim at the contours of the cells. In contrast, SMAA, an established marker for transformed PSC, started to be expressed at the third day. Thereafter, immunoreactivity for SMAA increased continuously, indicating an inverse expression of GFAP and SMAA during transformation. These results indicate that GFAP, due to the plasticity of its expression, can discriminate between the normal untransformed and transformed phenotypes of PSC. Furthermore, they suggest a role of GFAP not only as a reliable marker, but also in the maintenance and/or function of the normal differentiated phenotype of liver PSC.

[Comparison of physico-chemical properties of two forms of dopamine-beta-hydroxylase from chromaffin granules]. / Sravnitel'noe izuchenie fiziko-khimicheskikh svoistv dvukh form dofamin-beta-gidroksilazy iz khromaffinykh granul.

The purification procedures of both soluble and membrane-bound forms of dopamine-beta-hydroxylase have been developed. The membrane-bound form was solubilized by a detergent. Both preparations have been obtained in electrophoretically homogeneous form. The yield of soluble and membrane-bound enzyme forms by a described procedure was 22 mg and 15 mg, correspondingly, from 100 g of chromaffin granules paste. A comparative analysis of the main physico-chemical properties of the two enzyme forms has shown their identity. The effects of pH, ionic strength, oxidants and reducers on the EPR spectra of the two forms of dopamine-beta-hydroxylase have been investigated. A comparison of the EPR spectra of the two forms of the enzyme suggests that the copper environment of soluble and membrane-bound dopamine-beta-hydroxylases is practically identical.

[Effect of glutamic acid on the interrelationship of the effects of different activators of cerebral glutaminase]. / Deistvie glutaminovoi kisloty na vzaimootnoshenie éffektov razlichnykh aktivatorov glutaminazy mozga

When phosphate and tyroxine (activators of brain glutaminase) are used in small amounts, a potentiation of their stimulatory effect is observed. Higher concentrations exhibit an opposite effect. Glutamic acid has a strong inhibitory effect on all the activators of glutaminase given separately. The inhibitory effect of glutamate increases on lowering the pH. On the other hand the potentiation observed on adding two stimulators is increased greatly in the presence of glutamate. On the addition of tyroxine to other stimulators a greater potentiation and rise of glutaminase activity are observed. The potentiation, which occurs on the joint addition of phosphate and tyroxine, is raised with the increase of the amount of glutamic acid, while on the contrary on joining phosphate with other stimulators potentiation is reduced. Potentiation is variable and depends on the pH. Preincubation of brain mitochondrial fraction with guanidine chloride inhibits markedly the stimulatory effect of all the stimulators used, but their joint addition almost abolishes the potentiating effect. In the presence of glutamic acid, due to the increase of the cooperative effect between the two stimulators, glutaminase activity is greatly increased and sometimes its inhibitory effect is not even observed. The data obtained indicate that in brain glutamic acid in the presence of phosphate+thyroxine cannot be considered as an inhibitor of glutaminase and that the important factor here is not so much the absolute levels of the activators as their favorable combinations.

The immunoreactivity of glial fibrillary acidic protein in mesangial cells and podocytes of the glomeruli of rat kidney in vivo and in culture.

In this study the presence of glial fibrillary acidic protein (GFAP) in kidney is for the first time demonstrated in cryostat sections and cultures of isolated glomerular explants derived from rat kidneys. In double immunolabelling analysis of adult rat kidney sections using antiserum against GFAP and monoclonal antibody (mAb) against vimentin or desmin, the presence of immunoreactivity for GFAP could be observed in the glomerulus of the kidney and vascular cells situated in the peritubular space which expressed vimentin and desmin. Labelling of the sections with absorbed antiserum against GFAP completely abolished the staining in all these cells. The mAb against GFAP, clone GF12.24 which is known to label GFAP both in neural and non-neural cells, recognised its antigen only in the cells located in glomeruli. The investigations performed on early 2- or 3-day-old cultures from glomerular explants revealed different patterns of staining for GFAP in mesangial cells and podocytes: weak filamentous in mesangial cells and a strong non-filamentous perinuclear pattern in podocytes. Due to prominent perinuclear expression in podocytes GFAP may be considered as a marker of these cells. A different pattern of distribution of immunoreactivity for GFAP in podocytes and mesangial cells might be due to function-related posttranslational modifications of GFAP resulting in assembly or disassembly of GFAP filaments. The different pattern of staining for GFAP in the podocytes and mesangial cells, cells which exert a different influence on the capillaries of the glomeruli, suggests a role for GFAP in regulation of the tension and permeability of vascular walls. Previous investigations and present studies hint at GFAP as being a general marker of perivascular cells.

Dehydroepiandrosterone increases the zone [correction of in zone] of glutamine synthetase-positive hepatocytes in female rat liver: a putative androgenic effect.

The adrenal steroid dehydroepiandrosterone (DHEA) is a hepatocarcinogen and peroxisome proliferator in the rat, producing an increase in peroxisomes mainly in perivenular parts of the liver lobule. Glutamine synthetase (GS) is expressed exclusively in hepatocytes that directly surround the central terminal vein in rat liver. The GS-positive zone is wider in males than in females, covering about two to three cell layers in males and one to two cell layers in females. Treatment of rats with DHEA at a concentration of 0.6% in the diet for 4, 20, 32, 70 and 84 weeks resulted in an enlargement of the GS-positive zone in females, whereas no change was observed in males. In females treated for up to 32 weeks with DHEA, the relative mean width (RMW) of the GS-positive zone was as large as that observed in males. The increase in the RMW was paralleled by an increase in the number of GS-positive hepatocytes. Upon longer treatment, the width of GS expression decreased to that observed in untreated controls. The findings suggest an androgenic effect of DHEA. The areas of peroxisome proliferation, identified in haematoxylin and eosin- and periodic acid-Schiff-stained sections, and GS expression were not identical. Furthermore, preneoplastic and neoplastic liver lesions induced by DHEA were all negative for GS, indicating that they do not derive from the perivenular cells which show the most pronounced peroxisomal proliferation.

[Soluble cerebral metalloproteins. 1. Purification and properties of cerebral cortex cytochrome c]. / Rastvorimye metalloproteiny mozga. 1. Ochistka i svoistva tsitokhroma c iz kory golovnogo mozga

Cytochrome c from grey matter of brain has been obtained as a homogeneous preparation by electrophoresis on polyacrylamide gel and following electrofocusing in ampholine solutions. Its molecular weight, content of iron, redox potential and isoelectric point have been established. The absolute spectra of its oxidized and reduced forms are presented. Cytochrome c of brain cortex is similar in its properties to that obtained from other animal tissues as the heart and adrenal cortex.

[Effect of thiol reagents on cerebral glutaminase activity]. / Vliianiia tiolovykh reagentov na aktivnost' glutaminazy mozga.

It has been shown that the glutaminase activity of brain mitochondrial fractions, which is stimulated by various activators, is completely abolished on 10 min preincubation with parachlormercurybenzoate, 5,5'-dithiobis-(2-nitrobenzoate), N-ethylmaleimide, iodoacetamid, CdCl2, ZnCl2 and CuCl2. With the purpose of elucidating the role of SH-groups in glutaminase activity we have studied the possibilities of preventing loss of enzyme activity by substrates and activators. We have shown that glutamine is effective only in the case of CuCl2. It should be noted that preincubation of brain mitochondrial fractions with activators greatly reduces the inhibitory effects of thiol reagents. Besides, activators differ in their effect in preventing glutaminase inactivation by various SH-reagents. After preincubation of glutaminase with activators their protective effect depends on whether glutamin is added together with the inhibitor or after some time. In one case their protective effect increases, in the other decreases and in the third case remains unchanged. On the basis of the data obtained the authors conclude that SH groups of brain glutaminase are not present in the active center and have an important functional significance for its catalytic active conformation.

Dynamics of glial fibrillary acidic protein distribution in cultured glomerular podocytes and mesangial cells of the rat kidney.

Glial fibrillary acidic protein (GFAP) has recently been shown to be expressed in the glomerular podocytes and mesangial cells (MC) of kidney (Buniatian et al (1998) Biol Cell 90, 53-61). The different localization of GFAP in podocytes and MC has raised the question whether this might reflect specific cellular functions. To address this question, in the present study podocytes and MC in early (2, 3 day-old), prolonged (5, 7 day-old) and late (14, 21 day-old) primary cultures from out-growths of glomerular explants were used. Double-immunolabeling studies demonstrated that podocytes transiently acquire myofibroblastic features, characterized by the expression of smooth muscle alpha-actin (SMAA) and increased perinuclear reaction of GFAP in prolonged cultures. The morphological differentiation of cobblestone-like podocytes into process-bearing cells was followed by loss of the myofibroblastic marker, SMAA, de novo expression of desmin, and distribution of GFAP, vimentin and desmin into the processes. In late culture, GFAP and SMAA were nearly absent from the podocytes which maintained the cobblestone-like morphology. By contrast, the myofibroblastic features gained by MC during prolonged culturing increased with time. A myofibroblast-like cytoskeleton of podocytes and MC similar to that of healthy astrocytes suggest an increased spectrum of functional activities of these cells during the acquisition of myofibroblastic features. In addition, the present study provides a new combination of biochemical and biological features by which podocytes and MC can be distinguished in culture.

[Soluble cerebral metalloproteins. II. Superoxide dismutases of cerebral gray and white matter]. / Rastvorimye metalloproteiny mozga. II. superoksiddismutazy iz belogo i serogo veshchestva golovnogo mozga.

Superoxide dismutases (SOD) of high purity have been obtained from grey and white matter of bovine brain cerebral hemispheres. The SOD obtained have been shown to have three isoenzymes (a, b, c). A study of the catalytic and macromolecular properties of the SOD obtained from grey and white matter of cerebral hemispheres as well as their optical and electron paramagnetic resonance spectra indicates that both proteins possess similar properties. The possible function of SOD in grey and white matter of brain is discussed.