[Inhibition of aldehyde dehydrogenase activity in rat liver by cyclopropylethyl-containing benzoic acid amides]. / Ingibirovanie aktivnosti al'degiddegidrogenazy pecheni krys tsiklopropilétilsoderzhashchimi amidami benzoinykh kislot.

Influence of cyclopropylethyl-containing benzoic acid amides on the aldehyde dehydrogenase activity of the rat liver mitochondria was investigated. Values of I50 were measured for each of the compounds. The character of kinetic behavior of these reversible inhibitors was studied. It is shown that 2,5-dichloro-4-methylbenzoic acid amides reveal partially uncompetitive type of inhibition relative to acetaldehyde, while 2,4-dichloro- and 2,4-dichloro-5-methylbenzoic acid amides reveal changes in the character of inhibition from uncompetitive to mixed one. Inhibition was partially competitive with regard to reaction NAD+ cofactor. Though the studied compounds induced inhibition of a certain type with respect to each of the substrates, but on the whole the mechanism promoting a decrease of the ALDH-1 reaction rate appears to be more complex.

[Enzymes of ethanol metabolism in the liver of rats with varying alcohol motivation in acute alcoholization]. / Fermenty obmena étanola pecheni krys s razlichnoi alkogol'noi motivatsiei pri ostroi alkogolizatsii.

Alcohol dehydrogenase (ADH) activity does not change in ethanol-preferring rats (EP receiving ethanol injection in a dose of 2.5 g/kg; an increase of the dose to 4.5 g/kg leads to a descent of activity 60 min later. Enhancement of the reverse reaction activity 120 min after injection of ethanol both doses probably induce faster metabolism of acetylanhydride and thus absence of the adverse ethanol action in these animals. An increase of activity of NAD(+)- and NADP(+)-dependent isoforms of ALDH-II 60 min after their injection in a dose of 2.5 and 4.5 g/kg also contributes to this effect. Synchronous changes both in direct and reverse ADH reactions in water-preferring (WP) rats with 2.5 g/kg ethanol injection were observed: the activity increase 30 min later followed by normalization at the 60th min and a repeated increase 120 min later; a dose of 4.5 g/kg induced an increase of only direct ADH reaction activity at the 30th and 60th min. The liver mitochondria ALDH-I of WP were practically unsusceptible to ethanol in a dose of 2.5 and 4.5 g/kg. Activity of NAD(+)-dependent ALDH-II mitochondria decreased with 2.5 g/kg at the 30th and 60th min, respectively. Yet an increase in activity of isoforms in microsomes was observed. ADH activity in short-sleeping (SS) rats does not change both at 2.5 and at 4.5 g/kg doses. More intensive ethanol metabolism in these rats is probably connected with increased activity of MEOS and catalase.(ABSTRACT TRUNCATED AT 250 WORDS)

[Kinetic characteristics of enzymes of ethanol metabolism in rats]. / Kineticheskie kharakteristiki fermentov obmena étanola u krys]

Experimental animals were separated as for narcotic sleep length into short-sleeping and long-sleeping rat groups and as for alcohol motivation to rats preferring ethanol or water or an intermediate group as well. Alcohol- and aldehyde dehydrogenase reaction maximum speed as well as Michaelis-Menten constants for these enzymes were measured for each of these groups. Alcohol dehydrogenase affinity to cofactor in the reverse reaction was an order of magnitude higher as compared with the affinity to substrate in all the animal groups. Apparent Michaelis-Menten constant values were 1.5-2 times higher in short-sleeping and ethanol preferring rats in the direct reaction. There were no such differences for the reverse reaction. Alcohol dehydrogenase reaction maximum speed for short-sleeping group is close to that for animals preferring ethanol or water. For different forms of aldehyde dehydrogenase an increase of the apparent maximum speeds was distributed as follows: water preferring group < intermediate group < ethanol preferring group. Aldehyde dehydrogenase-1 Michaelis-Menten apparent constants for acetaldehyde were changed in the same way. Thus, data obtained suggest that ethanol metabolism speed along the path alcohol/aldehyde dehydrogenases are close in ethanol-preferring and short-sleeping rats.

[Amides of simple and complex ethers of glycolic acid--inhibitors of alcohol dehydrogenase in rat and human liver]. / Amidy prostykh i slozhnykh efirov glikolevoi kisloty--ingibitory alkogol'degidrogenazy pecheni krys i cheloveka.

Amides of glycolic ethers and esters have been synthesized and studied as the inhibitors of rat and human liver alcohol dehydrogenase. Amides of glycolic ethers inhibit the rat liver alcohol dehydrogenase activity by 50-85%, amides of esters by 10-40%. An analogous regularity has been established for human liver alcohol dehydrogenase. The inhibiting capacity of the compound for glycolic acid aromatic esters diamides increases depending on the position of two residua of glycolic acid: ortho < meta < para. A decrease in activity of the isoforms of rat liver aldehyde dehydrogenase does not exceed 40%. It is shown that glycolic acid ether amides are noncompetitive inhibitors, amides of aromatic esters in case of the substituent presence in the ortho- and para-positions are competitive or in the meta-position noncompetitive inhibitors. Linear correlation under the comparison of the inhibition constants with the corresponding parameters of hydrophobicity of butyl, 2-methylbutyl and 3-methylbutyl esters of glycolic acid have been found.

[Activity of enzymes of ethanol metabolism as a test in evaluating the effectiveness of sensitizing alcohol deterrents]. / Aktivnost' fermentov obmena étanola kak test dlia opredeleniia éffektivnosti antialkogol'nykh preparatov sensibiliziruiushchego deistviia.

A procedure is developed for determination of the efficiency of the antialcoholic drugs' action on the system of ethanol oxidation in vitro: alcohol dehydrogenase by the direct and reverse reactions and aldehyde dehydrogenase of subcellular fractions of the rat liver. This procedure is also used to determine the antialcoholic activity of a number of new compounds and to compare them with disulphiram (antabus, teturam), the known antialcoholic drug.

[Disulfiram inhibition of aldehyde reductase from the rat liver]. / Ingibirovanie disul'firamom al'degidreduktazy pecheni krys.

Disulphiram (tetraethylthiuram disulphide teturam, antabus), the known antialcoholic preparation, is studied for its effect on the aldehyde reductase activity (EC 1.1.1.1) in the rats' liver. Apparent Km and V are calculated for acetylaldehyde and NADH as well as Ki of disulphiram relative to the substrate and cofactor of the enzyme. The obtained data permit considering disulphiram a high-specific inhibitor of aldehyde reductase in rats' liver.

[Aldehyde dehydrogenases in the rat liver after implantation of a prolonged-action preparation of an alcohol deterrent]. / Al'degiddegidrogenazy pecheni krys pri implantatsii antialkogol'nogo preparata prolongirovannogo deistviia.

Activity of aldehyde dehydrogenase isoenzymes was studied in rat liver mitochondria and microsomes after implantation of the new antialcohol drug of the long-term effect synthesized on the basis of disulphirame. Disulphirame, both in vivo and in vitro was shown to inhibit dissimilarly these isoenzymes. The degree of sensitivity of various aldehyde dehydrogenase isoenzymes to disulphirame is important for estimation of the drug efficiency.

[Subcellular distribution and properties of aldehyde dehydrogenase in the rat liver]. / Subkletochnoe raspredelenie i svoistva al'degiddegidrogenazy pecheni krys.

The subcellular distribution and certain properties of rat liver aldehyde dehydrogenase are investigated. The enzyme is shown to be localized in fractions of mitochondria and microsomes. Optimal conditions are chosen for detecting the aldehyde dehydrogenase activity in the mentioned fractions. The enzyme of mitochondrial fraction shows the activity at low (0,03-0.05 mM; isoenzyme I) and high (5 mM; isoenzyme II) concentrations of the substrate. The seeming Km and V of aldehyde dehydrogenase from fractions of mitochondria and microsomes of rat liver are calculated, the acetaldehyde and NAD+ reaction being used as a substrate.

[Effect of SH-reagents on aldehyde dehydrogenase activity of the rat liver]. / Vliianie SH-reagentov na aktivnost' al'degiddegidrogenazy pecheni krys.

SH-reagents: tetraethylthiuram disulphide (TETD), 5,5'-dithiobisnitrobenzoic acid (DTNB), p-chloromercurybenzoate (p-ChMB), N-ethylmaleimide (NEM) were studied for their effect on the aldehyde dehydrogenase activity of mitochondrion (isoenzymes I and II) and microsome (isoenzyme II) fractions of the rat liver. TETD is established to inhibit isoenzyme I and isoenzyme II activity of mitochondrial aldehyde dehydrogenase by 100 and 50%, respectively, and the microsomal enzyme activity by 20%. DTNB and NEM inhibit 30-50% of the activity in two isoforms of mitochondrial aldehyde dehydrogenase having no effect on the enzymic activity in microsomes; p-ChMB inhibits completely the activity of the enzyme under study both in the mitochondrial and microsomal fractions. A conclusion is drawn that SH-groups are very essential for manifestation of the catalytic activity in the NAD+-dependent aldehyde dehydrogenase from mitochondrial and microsomal fractions.

[Activity of proteolytic enzymes in the kidney and blood serum of rabbits during implantation of different polyurethanes]. / Aktivnost' proteoliticheskikh fermentov pochek i syvorotki krovi krolikov pri implantatsii razlichnykh poliuretanov.

It is shown that the activity of neutral proteinase both in homogenate and in blood serum increases by the 14th day the D-1 sample being implanted. In the subsequent periods after implantation the enzyme activity in homogenate is the same. Three and six months after implantation the neutral proteinase activity in blood serum decreases as compared to the norm. The activity of acid proteinase in rabbit kidney homogenates lowers by the 90th day after implantation both for the D-1 and for A-10 samples. For the D-1 sample the enzyme activation in blood serum is observed by the 30th day after implantation, three months later it falls to reach the normal level in 6-12 months and inhibition activity on the 30th day after implantation on the A-10 sample. Such changes in the activity of enzymes in homogenates and blood serum may reflect certain stages of polyurethane biodestruction participation of various enzymic systems of the organism in these processes.

[Acid phosphatase activity in rabbit kidneys after implantation of different polyurethanes]. / Aktivnost' kisloi fosfatazy v pochkakh krolikov pri implantatsii razlichnykh poliuretanov.

Activity of acid phosphatase was determined in rabbit kidneys under subcapsular implantation of polyester-based polyurethane films (A-10) and films (D-1) containing the links of L-phenylalanyl-L-serine dipeptide in the main chain of the polymer. Optimal conditions are chosen for detecting activity of this enzyme in homogenates and in the lysosome enriched fraction of rabbit kidneys with L-glycerophosphate used as a substrate. Activity of acid phosphatase under the A-10 specimen implantation increases on the 7th and 14th day and later (during a year) does not differ from the normal level. Under the D-1 spectrum implantation the acid phosphatase activity remains increased for a longer period--up to one month. It is possibly due to the fact, that this polymer contains dipeptide fragments and is subjected to a more intensive enzymic destruction than the A-10 specimen.

[Production and properties of trypsin immobilized on a polyurethane matrix]. / Poluchenie i svoistva tripsina, immobilizovannogo na poliuretanovoi matritse.

Two methods were used to immobilize trypsin on the polyurethane carrier on the basis of toluylenediisocyanatepolyoxypropylene glycol due to interaction between the lyzine free amino groups and the enzyme arginine guanidine group and the prepolymer isocyanate group. The amount of the enzyme chemically bound by the two methods is about 50 and more than 70%, respectively. The substrate specificity of the initial and washed samples of the immobilized trypsin was studied with respect to three highly molecular substrates with different molecular weight and different charges--protamine, casein, hemoglobin. It is shown that independently of the method of binding the activity of the immobilized trypsin is the highest with respect to hemoglobin and is the lowest with respect to protamine. The samples of trypsin immobilized on the polyurethane carrier may be used in biology and medicine when creating the prolonged forms of the enzymic preparations.

[Growth of rat fibroblasts in tissue culture as affected by trypsin immobilized on polyurethane substrates]. / Vliianie tripsina, immobilizovannogo na poliuretanovykh podlozhkakh, na rost fibroblastov krysy v kul'ture tkanei.

The growth of fibroblasts of the rat subcutaneous tissue was studied as affected by different doses of trypsin, free and bound, on polyurethane substrates. The method of tissue culture provides essential criteria for estimating the degree of bioincompatibility of polymeric alloimplants in particular when immobilizing biologically active substances on them. Trypsin adsorbed on the polyurethane substrate diffusing gradually into the culture medium is established to inhibit the cell growth. Chemically bounded trypsin in the composition of the polymeric matrix at the early stages of cultivation stimulates for a long time the division of fibroblastic elements and further accelerates their degeneration. It is shown that on polymeric substrates containing no trypsin, the growth character and dynamics of the fibroblastic elements are similar on the whole to these indices for cultures grown in the plasm clot without the substrate.