[Hypoglycemic effect of an extract from Aronia melanocarpa leaves]. / Issledovanie gipoglikemicheskogo deistviia ékstrakta iz list'ev Aronia melanocarpa.

The action of extract from Aronia melanocarpa leaves to blood glucose level was investigated. It was shown that incorporated into drinking water and administrated intraperitoneally, the extract significantly reduce the blood glucose level of streptozotocin (STZ)-diabetic and normal rats.

New peptidomimetics of insulin.

New peptidomimetics that have been obtained in the course of our experimental work show distinct insulin-like activity both in vitro and in vivo. The first peptidomimetic (PM 1) is essentially a decapeptide in which sites of A (20-21) and B (19-26) chains of insulin are linked by the peptides bond (Cys-Gly-Glu-Arg-Gly-Phe-Phe-Tyr-Cys-Asn). The second peptidomimetic (PM 2) has similar set of amino acid residues, except that two aromatic amino acids corresponding to the residues of B chain of insulin (B24 and B26) have been replaced with their D optical isomers (Cys-Gly-Glu-Arg-Gly-DPhe-Phe-DTyr-Cys-Asn). The third peptidomimetic (PM 3) has been obtained through acylation of N-terminal of PM 1 by the use of palmitic acid. The peptidomimetic incorporating D aromatic amino acids (PM 2) was demonstrated to exhibit more pronounced hypoglycemic impact, while the acylation of decapeptide tends to prolong the effective time of peptidomimetic influence in vivo.

[Stimulation of glucose uptake in PC 12 and L 929 cells by extracts from Aronia melanocarpa leaves]. / Stimuliatsiia pogloshcheniia gliukozy kletkami PC 12 i L 929 ékstraktom iz list'iev Aronia melanocarpa.

The ability of extract from Aronia melanocarpa leaves to increase glucose uptake was investigated. It was shown, that the extract stimulated glucose uptake by cells PC12 and L 929 at the concentration close to native insulin.

[The prolonged action of an insulin peptidomimetic by the substitution of L-amino acid for its D-isomer]. / Uvelichenie vremeni deistviia peptidomimetika insulina putem zameny L-aminokislotnykh ostatkov ikh D-opticheskimi izomerami.

The synthesized decapeptide represents functionally important site for binding to the insulin receptor. Amino acid residues at position, 1-8 correlate with B-chain of insulin at position B19-B26, and the residues at position 9-10 correlate with A-chain at position A20-A21. The new peptide was obtained by substitution of two aromatic L-amino acid residues (B24 and B26) for their D-optical isomers. These peptides were tested with cell cultures L929 and PC12 (glucose uptake). Increased concentration of peptides correlated with stimulation of glucose uptake by cells. Studies carried out on animals with streptosotocine-caused diabetes showed that, synthesized peptides were able to decrease glucose level in blood, but decapeptide with D amino acid showed a more pronounced effect compared to the decapeptide with L amino acid.

Effects of isatin on atrial natriuretic peptide-mediated accumulation of cGMP and guanylyl cyclase activity of PC12 cells.

We have previously demonstrated that isatin (indole-2,3 dione), an endogenous compound widely distributed in mammalian tissues and body fluids, effectively inhibits atrial natriuretic peptide (ANP) receptor binding and ANP-stimulated guanylyl cyclase activity of rat membrane preparations. In the present study the effects of isatin on ANP-mediated accumulation of cGMP and guanylyl cyclase (GC) activity of PC12 cells were studied. Isatin (0.1 mM) effectively inhibited ANP-stimulated GC-activity of broken cells but was nearly inactive in attenuating ANP-dependent accumulation of cGMP in intact PC12 cells. The ATP-analogue adenylylimidodiphosphate (AMP-PNP) slightly potentiated the ANP effect on GC activity in broken cell preparations and significantly reduced GC sensitivity to isatin. Isatin caused a more pronounced reduction of ANP-dependent cGMP accumulation in cells grown in the presence of 10% embryonal calf serum (ECS) than in 0.5% ECS. The data obtained suggest that, in intact cells, the manifestation of the isatin effect on ANP-mediated signal transduction may depend on intracellular factor(s), possibly interacting at the kinase domain.

The lacZ gene transfer into L929 cells and [14C]-DNA tissue distribution following intraperitoneal administration of new pH-sensitive lipoplexes in mice.

The efficacy of lacZ gene transfer into the L929 cell line and a local [l4C]-DNA delivery in male NMRI mice (10-12 weeks old), were studied using new pH-sensitive liposomes, containing phosphatidylcholine/glycyrrhizin (PC/GL) or alpha-tocopherol ester of succinic acid (PC/TSA). The reporter gene (pQE-LacZ plasmid) was transferred into L929 cells using corresponding lipoplexes, 0.5% of cells being transfected. Tissue distribution of Gasserian ganglion neurinoma cell [14C]-DNA fragments and corresponding PC/GL and PC/TSA lipoplexes, were examined following intraperitoneal administration of a 24 h postdose. The [14C]-DNA itself was not detected in any organs at a 1.5 h postdose. The use of PC/GL or PC/TSA lipoplexes considerably changed the biodistribution of [14C]-DNA in mice tissues. The maximal content of [14C]-DNA for both types of lipoplexes was observed in the intestine (50% dose equiv./g) and the spleen (30% dose equiv./g). The content of [14C]-DNA in liver and kidneys was equal to 4 and 10% for liver and kidneys in the case of PC/GL-lipoplexes, and 15 and 6%, for PC/TSA, respectively. Thus, the tropicity for PC/GL-lipoplexes to liver was not detected under i.p. administration.

[Specific binding and uptake of peptide ligand modified liposomes by PC12 cells]. / Issledovanie spetsificheskogo sviazyvaniia i pogloshcheniia modifitsirovannykh peptidnym ligandom liposom kletkami PC12.

Possible employment of cell-specific peptide for the specific adsorption and uptake by cells. It was shown, that apoprotein E 139-158 peptide increases liposomal binding followed by receptor-mediated endocytosis by cells PC12.

Modulation of glutamate neurotoxicity in the transformed cell culture by monoamine oxidase inhibitors, clorgyline and deprenyl.

Addition of 30mM glutamate to the culture medium decreased growth of rat glioma C6 cells accompanied by a decrease of DNA synthesis and an increase of lactate dehydrogenase (LDH) detected in the conditioned medium. The presence of 1 microM deprenyl attenuated the glutamate effect on cell growth only during the first 24-48 h incubation and had a minor influence on the glutamate-induced decrease of DNA synthesis. Clorgyline (1 microM) potentiated glutamate-induced DNA synthesis during the first 24 h incubation without significant influence on the cell growth. Deprenyl slightly attenuated the glutamate-induced LDH increase during 24 h incubation but potentiated the glutamate effect at 96 h. Clorgyline decreased the glutamate influence at 24 h and especially 96 h. All these effects were observed in the absence of exogenous monoamines in the culture medium. These results suggest that in transformed cells monoamine oxidase (MAO) inhibitors may influence processes of cell death via MAO-independent mechanisms.

[Transfer of the functional genes into eucaryotic cells by neutral phospholipid liposomes]. / Perenos funktsional'nykh genov v kletki éukariot s pomoshch'iu neitral'nykh fosfolipidnykh liposom.

Transfection of plasmid DNAs containing b-galactosidase gene (pQE-LacZ) or alkaline phosphatase (pCSEAP) into L929 cell line using was studied. The complexes between plasmid DNA and liposomes containing Ca ions and glycyrrhizic acid or &-tocopherol caused successful transfection of functional genes into L929 cells. The efficiency of transfection of plasmid DNAs into L929 cells using polynucleotide-metallo(II)-liposome complexes were 30-50% from the efficiency value of calcium phosphate coprecipitation transfection.

[A synthetic fragment of insulin with insulin-like biological activity]. / Sinteticheskii fragment insulina s insulinopodobnoi biologicheskoi aktivnost'iu.

We have used computer modeling of insulin 3-D structure and experimental data about action of site point mutation on insulin activity to design functionally important domain with signaling activity and synthesized peptide than might be sufficient for the binding to insulin receptor. The designed and synthesized peptide consist of ten residues and may be obtained in two forms: oxidized and reduced (with or without disulfide bond). The synthesized decapeptide peptide represents functionally important site for binding to the insulin receptor. Amino acid residues at position 1-8 correlate with B-chain of insulin at position (B19-B26). Residues at position 9.10 correlate with A-chain at position A-10-A21. This peptide was tested with cell culture L-929 (glucose uptake) in comparison with bioactive commercial peptide (R-G-FF) and insulin. It was shown that synthesized peptide exhibit biological activity at molar concentration 0.01-1 mkM. Our results successfully demonstrate the synthetic insulin fragment have insulin-like biological activity.

[Comparative study of collagen in hypertrophic and keloid cicatrix]. / Sravnitel'noe issledovanie kollagena gipertroficheskikh i keloidnykh rubtsov.

The relative percentage of type III to type I collagen, the ratio of alpha 1(I) to alpha 2(I) collagen chains and the ratio of dimers (beta-chains) to monomers (alpha-chains) in type I collagen have been measured in solubilized collagen fractions from keloids and hypertrophic scars aged about 1-7 years after burn. In tissue samples the content of crosslink with structure of pyridinoline were analyzed and expressed as mole of crosslink per mole of collagen. A comparison between hypertrophic and keloid scars has shown that the young (about 1 year) hypertrophic scars have higher ratios alpha 1(I)/alpha 2(I) and beta 11 + beta 12/alpha 1(I) + alpha 2(I). The increased proportion of beta-chains in the younger hypertrophic scars approximated to the same level as in normal skin within 7 years after lesion. There was no decrease in the ratio dimers/monomers of collagen type I with age of keloid scar tissue. The relative amount of collagen type III in young keloid scars was found decreased as compared to age-matched hypertrophic scars (13 +/- 3 and 17 +/- 7 respectively), but was similar in the older scars. The average pyridinoline crosslinks content per mole of collagen in keloids was 2 times as high as in hypertrophic scars. The data support the suggestion that general, as well as peculiar disturbances of collagen metabolism are involved in the development of keloids and hypertrophic scars.

[The effect of phosphatidylcholine on repair processes in liver cells in acute CCl4 damage]. / Vliiane fosfatidilkhonlina na reparatsionnye protsessy v kletkakh pecheni pri ee ostrom povrezhdenii CCL4.

Effect of phosphatidylcholine, isolated from soy beans and sunflower seeds for laboratory use, on synthesis of RNA, DNA, albumin and content of newly synthesized mRNA in polyribosomes was studied in hepatocytes after chemical hepatectomy produced by single administration of CCl4 into rats; histological and histochemical studies of liver tissue were also carried out. Phosphatidylcholine from these plants was found to prevent hepatocyte dystrophy and necrosis development, to activate the macrophage response and to stimulate reparation inducing synthesis and secretion of the tumor necrosis factor. The rate of highly labelled RNA synthesis, mainly mRNA, decreased in liver tissue of rats treated with CCl4, was increased approximately 2-fold after the phospholipid administration. The phospholipid from soy beans restored the albumin synthesis as well as the content of newly synthesized mRNA in rat polyribosomes, while phosphatidylcholine from sunflower seeds restored effectively the mitochondrial DNA synthesis. Promising application of these phosphatidylcholines as hepatoprotectors is discussed.

[The effect of ascorbic acid on the collagen synthesis in skin fibroblasts of children with funnel chest]. / Vliianie askorbinovoi kisloty na sintez kollagena fibroblastami iz kozhi detei s voronkoobraznoi deformatsiei grudnoi kletki.

Relative synthesis of collagen was studied in skin fibroblasts of children with funnel chest and of corresponding age children (control) in presence of ascorbic acid. In presence of ascorbic acid the rate of collagen synthesis was 2-2.4-fold lower that in corresponding controls both in proliferating and stationary cultures. At the same time, relative synthesis of collagen was quite similar both in the patient and control fibroblasts in presence of ascorbic acid. Estimation of the 14C-Hypro/14C-Pro ratio in collagens isolated from cultural media showed that there was no difference in the hydroxylation rate of collagens in control and patient fibroblasts. These data suggest that funnel chest is one of the forms of systemic connective tissue diseases, which impaired mainly the cartilages.

[Structural characteristics of collagens from the skin and rib cartilage of patients with Ehlers-Danlos syndrome type II]. / Strukturnye kharakteristiki kollagenov kozhi i rebernogo khriashcha bol'nykh s sindromom Elersa-Danlo II tipa]

Collagens were analyzed in skin and rib cartilage of 9 patients with Ehlers-Danlos syndrome of the II type. Electrophoresis and CNBr-peptide mapping showed that extended inserts and deletions as well as rough impairments of post-translation processing were not detected in collagens of the I, II and III types from these patients. In the patients with Ehlers-Danlos syndrome of the II type distinct increase was observed both in the total ratio of collagens III/I (P = 0.95) and in the ratio of intact collagens III/I free of cross-links. A decrease in content of dimers beta 11 and beta 12 was found in two patients. The data obtained suggest that the Ehlers-Danlos syndrome of the II type involved deteriorations in the structure of collagens I responsible for decrease in stability and sometimes for impairments in cross-link formation. Increase in content of collagen II fraction, predisposed to proteolytic hydrolysis of terminal sites, as well as elevated sensitivity of collagen II to pepsin hydrolysis were found in collagens of rib cartilage from patients with the syndrome and with funnel chest deformation. This suggests the lowered stability of collagen II from rib cartilage in funnel chest deformation.

[Changes in the structure of type I collagen and cross-links between type I and type III collagen chains in a patient with funnel chest]. / Narushenie struktury kollagena I tipa i nalichie sshivok mezhdu tsepiami kollagenov I i III tipa u bol'nogo s izolirovannoi formoi kilevidnoi deformatsii grudnoi kletki.

Skin and rib cartilage collagens were studied in patient 1.I.K. with isolated form of pigeon chest as well as in a group of children without any impairments of connective tissue. Distinct decrease in stability of collagen I, an increase in the ration of alpha 1 (I)/alpha 2(I) chains and impairment in formation of beta 12 dimers were detected in the patient with pigeon chest. In the patient skin total ratio between collagens I and III, calculated from a content of BrCN-peptides, was similar to normal level, whereas the proportion was markedly increased between intact molecules of collagens III and I free of cross-links, which was calculated from the ratio of alpha 1(III)/alpha 2(I) chains. Presence of cross-links between alpha 1 (III) and alpha 2 (I) chains as well as between alpha 1 (III) and alpha 2 (I) chains was detected after peptide mapping of polypeptides arranged in the region of beta 11 and beta 12 dimers. All the collagen I preparation, extracted from skin of the patient 1.I.K., contained molecules with unstabilized N-terminal sites. These results suggest that mutation occurred in the N-terminal region of alpha 1(I) chain. Analysis of collagen from the patient 1.I.K. rib cartilage demonstrated a slight decrease in total stability of collagen II as well as elevated concentration of collagen II molecules containing unstabilized N-terminals. Mechanisms responsible for formation of cross-links between polypeptide chains of collagens I and III detected in human skin are discussed.