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At unsaturating concentration of 2-oxoglutarate, ATP markedly inhibited the adrenal oxoglutarate dehydrogenase complex activity due to chelation of magnesium ions required for activity of the enzyme. At the same time, ATP opposed competitively the activating influence of a positive effector ADP.

Changes in cellular composition of subcutaneous connective tissue were studied on the film-like preparations immediately or some time after single and repeated general overheating. It is suggested that the discovered changes in fibroblasts, histiocytes and mast cells reflect the connective tissue reaction directed at the maintenance of the metabolic homeostasis.

Based on 93 observations on application of a mechanic suture for vesico-digestive anastomoses and anastomoses between the hepatocholedochus and duodenum, it has been found that these operations have a number of advantages over routinely used procedures and could be employed in everyday surgical practice, thus facilitating technical accomplishment of surgical procedures on bile passages.

The modification of SH-groups in the native isocitrate dehydrogenase accessible to 5,5-dithiobis (2-nitrobenzoic acid) (DTNB) is accompanied by the enzyme inactivation. Isocitrate rather than NADP and MnCl2 protects two SH-groups of the enzyme from modification by DTNB and attendant inactivation. The isocitrate dehydrogenase inactivation by DTNB obeys pseudofirst-order reaction kinetics. The number of DTNB-titrated sulphydryl groups does not change after the isocitrate dehydrogenase denaturation by sodium dodecyl sulphate. In the presence of manganese ions isocitrate and to a lesser extent NADP protect isocitrate dehydrogenase from the inactivation induced by 2,3-butanedione, a specific modifier of arginine residues. It has also been shown that the methylene blue-sensitized photoinactivation of the enzyme associated with the photooxidation of histidine residues decreases in the presence of NADP. These data provide evidence for an essential role of the SH-groups, arginine residues and, probably, histidine in the functioning of NADP-dependent isocitrate dehydrogenase from adrenal cortex.

The results of the study of protein and RNA biosynthesis and inducation of glucose-6-phosphatase activity in the rat liver at natural (seasonal) fluctuations of the steroid background are presented. It is shown that the adrenal gland seasonal activation increases incorporation of precursors labeled (l14C-leucine and l14C-orotic acid) into total liver proteins and RNA and enhances glucose-6-phosphatase activity in the rat liver. The conclusion is drawn that the changes in the endogenous corticosteroid level have regulative significance for protein biosynthesis in the rat liver.

Studies have been made on the rate of spontaneous, ascorbate- and NADP.H-dependent lipid peroxidation in the adrenal cortex, liver heart of rats, rabbits and cattle. It was shown that in spite of some species differences in predisposition of tissues to lipid peroxidation. The highest rate of this process is characteristic of the liver of all the animals investigated.

Pyruvate kinase from bovine adrenal cortex was purified to an electrophoretically homogeneous state. The molecular weight of the native enzyme is about 230 000, that of one subunit is 57 000. The maximal values of the pyruvate kinase initial reaction rate were obtained in 50 mM imidazole-acetate buffer within the pH range of 6.8 to 7.0. The curve of the initial pyruvate kinase reaction rate versus phosphoenolpyruvate (PEP) and ADP concentrations is hyperbolic and obeys the Michaelis-Menten kinetics with Km for PEP and ADP of 0.055 X 10(-3) M and 0.25 X 10(-3) M, respectively. The enzyme is activated by Mn2+ and Co2+ by 43 and 38%, respectively. IDP, GDP, and UDP may be used as analogs of ADP. The enzyme is not activated by fructose-1.6-diphosphate and is inhibited by L-phenylalanine and ATP.

The 2-oxoglutarate dehydrogenase complex from bovine adrenal-cortex mitochondria has been purified by polyethylene glycol fractionation, ultracentrifugation through a layer of sucrose, isoelectric precipitation and gel filtration of Sepharose 4 B. The specific activity of the preparation obtained wa 9.9 U/mtg of protein; the sedimentation coefficient, S20, w, was 30 S. The results of sodium dodecyl sulphate polyacrylamide gel electrophoresis indicated decomposition of the 2-oxoglutarate dehydrogenase complex into 3 clear-cut protein fractions with mobilities corresponding to molecular weights of 51 000, 56 000 and about 110 000. Michaelis constants for the reactants of the 2-oxoglutarate dehydrogenase complex reactions were: 2-oxoglutarate = 200 micro M; CoA - 4,5 micro M; NAD - 25 micro M.

A reduction of blood corticosteroid content was observed in rats blood after the administration of 3-acetylpyridine. The rats given ACTH after 3-acetylpyridine showed a lesser elevation of corticosteroids in the blood and adrenal gland tissue than the intact animals; 3-acetylpyridine diminished the activity of dehydrogenase glucose-6-phosphate in the adrenal glands. The authors suggested that the action of acetylpyridine was realized at the adrenal gland level and consisted in inhibition of the NADP-H2 generation in the dehydrogenase systems.

Corticosteroid binding protein, transcortin, was isolated using biospecific and hydroxyapatite chromatographic procedures. Mr-60,000 of transcortin was evaluated by means of electrophoresis; isoelectric points of the protein and of its complexes were detected. The association constants of transcortin with cortisol at 4 degrees constituted 2.8.10(8) M-1/mol of protein from intact animals containing one binding site and 9.8.10(8) M-1/mol of protein from impaired rates containing 0.39 binding site per a molecule. The maximal cortisol-binding activity of transcortin was shifted towards more alkaline pH value under the pathological conditions. Circular dichroism spectra of the transcortin-cortisol equimolar complexes were studied. The proteins studied were dissimilar in their main physicochemical properties and patterns of the steroid binding.

Isolation of the pyruvate dehydrogenase complex from bovine adrenal cortex and its purification including fractionation by polyethyleneglycol, ultracentrifugation and gel filtration on Sepharose 4B is described. The preparation obtained having the specific activity of 4,5 U/mg was purified 370-fold with a yield of 37%. Under polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate the pyruvate dehydrogenase complex is degraded into 4 protein fractions with the mobility corresponding to the molecular weights of 74 000, 56 000, 42 000 and 37 000.

Systematic performance of fibroduodenoscopy in patients with diseases of bile tracts and the pancreas made it possible in 90 cases to reveal polyps of papilla duodeni major, which were the cause of chronic recurrent pancreatitis. An experience with 50 operations evidences that transduodenal polypectomy is a radical method of treatment obviating recurrences of pancreatitis.

The dependence of pyruvate kinase reaction rate on the concentration of one of the ligands--ADP or MgCl2--at constant concentrations of the other ligand was studied. The enzyme activity vs ligand concentration curves have fairly symmetrical peaks which correspond to the range of approximately equal ligand concentrations. The S-shaped dependence is observed only over the range of concentrations close to the dissociation constant for the Mg-ADP- complex (0.7 mM) under the given experimental conditions. The data obtained are consistent with the results of the first model kinetics within the framework of the London-Steck theory. The substrate for pyruvate kinase is the Mg-ADP- complex, while free Mg2+ and ADP3- competitively inhibit the enzyme. The inhibition constants are equal to 44 and 1 mM, respectively. The inhibiting effects of the metal and dinucleotide may be due to the competition with the substrate for the enzyme active site. Taking into consideration the fact that the binding of one of the ligands to the enzyme depends on the presence of the other ligand, a conclusion is drawn that Mg2+ forms a bridge with ADP3- and pyruvate kinase from adrenal cortex.

Glucose-6-phosphatase (G-6-Phase) activity in the rat liver is established to correlate directly with the content of corticosteroids in blood: it lowers with hypocorticoidism (adrenalectomy) and rises with hypercorticoidism (stress). The highest G-6-Phase activity in the liver of the intact animals is observed in autumn, the lowest one in spring, i.e. in the periods when the adrenals function has minimal and maximal values, respectively. Thiamin (0.4 g/kg) is shown to cause a decrease in the G-6-Phase activity in the liver of the intact rats and adrenalectomized or hypophysectomized animals. An assumption is advanced that the found in the experiment a pronounced insulin-like effect of vitamin B with respect to the G-6-Phase activity is connected with an intensified synthesis of the corresponding hormone in the pancreas.

The interaction of succinate dehydrogenase from the bovine adrenal cortex with succinate and oxaloacetate was studied in the process of its activation-deactivation. It is supposed that an intermediate unstable complex of succinate dehydrogenase with oxaloacetate plays an important role in the changed enzymic activity.

The rate of oxygen uptake by mitochondria of bovine and rat adrenals was determined during oxidation of the Krebs cycle substrates. Succinate is established to be oxidized most actively under in vitro conditions.

The activity of glucose-6-phosphate dehydrogenase (EC 1.1.1.44), transketolase (EC 1.1.1.44), transketolase (EC 1.1.1.49), 6-phosphogluconate dehydrogenase (EC 2.2.1.1.) and also the thiaminediphosphate (TDP) content were investigated on the 8th day after adrenalectomy. With compensated sodium dysbalance the removal of suprarenals is shown not to change the activity of dehydrogenases, but it does lower the transketolase activity and the TDP level. A seven-fold administration to adrenalectomized animals of nicotinic acid, thiamine or a simple injection of nicotinamide normalize the transketolase activity through raising the TDP level. The fact of the reduced transketolase activity in the kidneys in hypocorticotism being due to deficiency of the co-enzyme is also proved by the presence of the TDP-effect in vitro.

The NADP-dependent decarboxylating malate dehydrogenase was isolated from the cytoplasmic fraction of bovine adrenal cortex and purified 3530-fold by 3-fold ammonium sulfate fractionation, ion-exchange chromatography on DEAE-Toyopearl 650 M and DEAE-Sephadex A-50 with subsequent two-fold gel filtration through Toyopearl HW-55. The specific activity of homogeneous enzyme preparations was equal to 60 U/mg protein with a 30% yield. The enzyme molecular weight as determined by gel filtration on Sephadex G-20 was 155000. Upon polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate malate dehydrogenase dissociated into two subunits with Mr 77000. The Arrhenius plot for the reaction rate showed a break at 30 degrees C. The values of activation energy and temperature coefficient above and below the breakpoint were equal to 45049 and 147188 J X mol-1; 1.68 and 2.63, respectively. Within the temperature range of 26-40 degrees C, malate dehydrogenase exhibited hyperbolic kinetics with respect to the substrate. At 30 degrees C, Km for malate was equal to 250 microM, whereas at 40 degrees C it was 130 microM. The curve for the dependence of the initial reaction velocity versus NADP concentration was S-shaped. The Hill coefficient was 1.4, which testifies to positive cooperativity of NADP interaction with malate dehydrogenase.

In experiments on rats the degrees of the central m-cholinergic blocking (by the ability to suppress arecoline-induced tremor /AT/) and dopamine-potentiating (by potentiation of apomorphine-induced stereotypy (AS] effects of amizyl, glypine, scopolamine and 4-methylpyperidylbenzylate (4-MP) and an esther of phenylcyclopentylglycolinic acid and tropanol (PCT) were compared. It was found that with respect to AS and AT one can distinguish central m-cholinergic blocking agents with milddly (PCT, glypine) and strongly (4-MP, amizyl) dopamine-potentiating properties. None of these compounds administered in the doses corresponding to ED84 by AS influenced nicotine-induced tremor in rats.

The effects of thiamine and oxythiamine on glucoso-6-phosphate, fructoso-6-phosphate, ATP, aldopentoses, glucose and glycogen levels were studied in the liver of rats with different hormonal levels. Thiamine and insulin were shown to produce a similar effect on the liver levels of hexosomonophosphates, aldopentoses and glucose. Oxythiamine effects as compared to those elicited by thiamine and insulin are always contrasting. It is suggested that the insulin-like action of thiamine is consequent on the primary effect the vitamin exerts on the functional activity of the insular apparatus of the pancreas.

The activity of succinate dehydrogenase from bull adrenal cortex was studied as affected by malonate and oxaloacetate. The both substrate analogs without preincubation (separately and in the mixture) inhibit the enzyme by the competitive type. After a 3 min oxaloacetate preincubation of the enzyme inhibition is of a mixed character. Malonate under these conditions lowers the oxaloacetate effect without changing the type of inhibition. It is supposed that the protective effect is due to a high rate of formation and decay of the enzyme-inhibitory malonate complex.

At low concentrations of Mg2+ or Mn2+ the reaction catalyzed by isocitrate dehydrogenase from bovine adrenal cortex proceeds with a lag period which disappears as a result of the enzyme saturation with Mn2+ or Mg2+. The nu o versus D,L-isocitrate concentration curve is non-hyperbolic, which may be interpreted either by the presence of two active sites with different affinity for the substrate (K'mapp = 2.3 and 63 microM) within the enzyme molecule or by the "negative" cooperativity of these sites. The apparent Km value for NADP lies within the range of 3.6-9 microM. High concentrations of NADP inhibit isocitrate dehydrogenase (Ki = 1.3 mM). NADP.H inhibits the enzyme in a mixed manner with respect to NADP (Ki = 0.32 mM). In the presence of NADP.H the curve nu o dependence on NADP concentration shows a "negative" cooperativity between NADP binding sites. The reverse enzyme-catalyzed reaction of reductive carboxylation of 2-oxoglutarate does not exhibit any significant deviations from the Michaelis-Menten kinetics. The Km value for 2-oxoglutarate is 120 microM, while that for NADP.H is 10 microM.

2- Oxoglutarate dehydrogenase from bovine adrenal glands is inactivated under the actions of 2,3-butanedione, a modifier of arginine residues. On treatment of 2-oxoglutarate dehydrogenase with 2,3-butanedione in the presence of 2-oxoglutarate the basal activity is maintained, while enzyme sensitivity to the stimulatory effect of adenosine-5'-diphosphate (ADP) is lost. The data obtained provide evidence for the positive effector, ADP, to act by an allosteric mechanism. Arginine residues are likely to incorporate into both the active and allosteric centers of adrenal 2-oxoglutarate dehydrogenase.

Malate dehydrogenase from bovine adrenal cortex has been purified to homogeneity, using affinity chromatography on 2',5'-ADP-Sepharose 4B. The kinetic data do not contradict the consecutive mechanism of the reaction with the ordered addition of substrates: NADP binds first, then malate. The enzyme conformation initiated by NADP and malate binding is less thermostable. Malate dehydrogenase has intrinsic tryptophan fluorescence with the spectrum maximum at 335 +/- 1 nm, half-width of 50 +/- 1 nm and quantum yield of 0.08. The tryptophan residues belonging to class 1 (75%) and class 2 (25%) make the main contribution to the intrinsic fluorescence of malate. The binding of cofactors and substrates results in the quenching of enzyme fluorescence. The values of dissociation constants for malate dehydrogenase complexes with NADP (4 microM), with NADP . H (8 microM) and with pyruvate (2.5 mM) correlate with the corresponding values of Km. The shifts in pH of the medium induce changes in the fluorescence parameters which are probably related to conformational changes in the enzyme molecule. The changes in the fluorescence parameters correlate with the alterations of the malate dehydrogenase enzymatic activity.

The hyperbolic dependence of the initial rate of the adrenal pyruvate dehydrogenase complex-catalyzed reactions on pyruvate, CoA and NAD concentrations was established. The Lineweaver--Burk plots of v0 against one substrate concentration at constant unsaturating concentrations of other substrates represent families of parallel lines. The Km values for pyruvate, CoA and NAD are 0,017, 0.005 and 0.030 mM, respectively. CoA-SAc was shown to compete with CoA (Ki=0.067 mM) whereas NADH--with NAD (Ki=0.023 mM). Both CoA-SAc and NADH are uncompetitive inhibitors with respect to pyruvate. The inhibition of CoA-SAc against NAD is of a mixed type, while that of NAD against CoA is non-competitive. The results obtained are in agreement with the kinetic model of a three-site "ping-pong" mechanism.

An investigation into the total lipids, fatty acids, total phospholipids and ATP content in the liver of rats given nicotinamide, separately and together with hydrocortisone, showed that the disclosed shifts mutually correlate well and may be explained in keeping within the bounds of the idea as to the lipotropic action of the preparations. The coincidence of the corticosteroids and nicotinamide effects in regards to mobilization of lipids and their oxidation in the liver presumes a hormonal causation of shifts on the level of lipids metabolism.

Partially purified preparations of palmitoyl-CoA dehydrogenase from rabbit adrenal glands, liver and heart tissues exhibited similar kinetic parameters. Km value constituted 6.58, 5.26 and 6.67 microM for the enzyme from adrenal glands, liver and heart tissues, respectively. At the same time, palmitoyl-CoA dehydrogenase possessed lower catalytic capacity in adrenal glands due to the decreased amount of the enzyme as compared with that of liver or heart tissues.

Rates of thiamin diphosphate accumulation in rat liver tissue and its subsequent depletion were decreased within the first hour after vitamin B1 administration into the animals with oxygen insufficiency. Hypoxia apparently inhibited simultaneously the processes of thiamin diphosphate biosynthesis and degradation, as a result of which content of the coenzyme was unaltered in tissues under conditions of usual intake of thiamin. The data obtained suggest that the activity of enzymes, participating in thiamin diphosphate turnover and estimated in vitro do not reflect their real functioning in the whole organism. Importance of ATP, ADP and pyridine nucleotides is considered as regulating agents of enzymes participating in thiamin diphosphate turnover under hypoxia.

Thiamine effect on the blood 11-HOCS, hydrocortisone and corticosterone levels were studied in patients subjected to herniotomy and/or appendectomy under local anaesthesia. Intramuscular injections of thiamine in a dose of 0.12 g one day and 1.5 to 2 hours before surgery reduced the corticosteroid reaction prior to the operation (psychogenic factor effect) and at the height of the surgery (operation trauma effect). The subsequent administration of the vitamin averted a decrease in the blood corticosteroid level within the postoperative period. Positive results of experimental and clinical studies allow recommending thiamine as an effective remedy for adrenal gland protection from functional exhaustion at surgical stress.

The 2-oxoglutarate: 2,6-dichlorophenolindophenol (DCPIP)--oxidoreductase reaction catalyzed by the oxoglutarate dehydrogenase complex from bovine adrenal glands corresponds to the kinetic mechanism of a "ping-pong" type. There are signs of positive cooperativity of the oxoglutarate dehydrogenase interaction with the substrate and negative cooperativity of that with the electron acceptor. The half-maximal rate of the model reaction is provided by 0.01 mM concentrations of 2-oxoglutarate and DCPIP. The exceeding of the DCPIP optimum concentration (0.1 mM) results in the enzyme inhibition.