The activity of Na+, K+-ATPase from bovine brain in vitro was studied as affected by some neuroleptics (levomepromazine, chlorpromazine, perphenazine and haloperidol), antidepressants (imipramine and iproniazid) and psychostimulants (amphetamine) as well as by benactyzine and procaine. The degree of the enzyme inhibition by these drugs estimated by means of I 50 and apparent inhibitor constants (Ki) or rate constants (k) was different. Sensitivity of the brain Na+, K+-ATPase to the drugs decreased in the following order: levomepromazine, chlorpromazine, perphenazine, haloperidol, imipramine, iproniazid, benactyzine, procaine and amphetamine. Competition for the enzyme was revealed between sodium and some of the drugs investigated (levomepromazine, chlorpromazine, perphenazine and impramine) as well as between potassium and other drugs (haloperidol, genactyzine and amphetamine). It is suggested that the inhibition of the brain Na+, K+-ATPase by psychotropic drugs may be a part in the biochemical mechanism of their sedative-tranquilizing activity.

In 12, 24 and 48 hours after a single injection of phenobarbital, barbital-sodium and pentabarbital-sodium in doses of 80 175 an 40 mg/kg respectively an increased synthesis of protein in the cell-free protein-synthetizing system and a rise in the level of cytochromes b5 and P-450 in the liver microsomes of female rats were noted. The maximal changes were registered following introduction of phenobarbital the inducing capacity of barbital-sodium and pentabarbital-sodium twice as low. With chronic introduction of the drugs the tolerance with respect to all of them develops at an equal rate, which excludes the dependence of this phenomenon upon the induction of microsomal metabolizing enzymes of the liver.

Stability of alpha-ketoglutarate decarboxylase (alpha-KGDC) from the bull brain was studied in different temperature regimes. The high-purified preparations of alpha-KGDC are highly unstable both when kept at a temperature of 0 degrees C and as affected by temperature. The least loss of the alpha-KGDC activity is observed in the preparations obtained after lyophilization and stored for a long time as powder. The temperature inactivation may be prevented by adding to the medium Ca2+ (10(-3) M) and TPP (10(-2) M) as well as TPP and Ca2+ and Mg2+ in different combinations. At low temperatures none of the mentioned components and such substances as histidine and serum albumin has no stabilizing effect on alpha-Kgdc preparations show that the inhibitory effect of the latter is more pronounced. It is peculiar to both less purified and highly purified alpha-KGDC preparations. The action of urea is less pronounced and is greatly similar by the inhibitory effect as compared to alpha-KGDC from the pigeon muscles.

Experimental investigations have shown estradiol-dipropionate and insulin to induce an elevated activity of glucose-6-phosphate- and 6-phospho-gluconate-dehydrogenase in the uterus and the liver. Insulin potentiates the inducing action of estradiol on the pentosophosphate cycle dehydrogenases when both of them are used concurrently. For insulin to display its inducing effect a definite level of endogenous estradiol in the organism is necessary, for insulin fails to exert a specific influence on the study of dehydrogenases in sexually immature and ovariectomized animals.

The effect of neuroleptics, antidepressants, somnifacients and antiepileptic drugs on Na+- and K+-dependent transitions in the preparation of the transport ATP-ase from renal tubules of the guinea pig were looked into by using the spinal probes procedures. Neuroleptics inhibit most strongly (by 100--67 per cent) the conformant transition in the Na+- K+-dependent ATP-ase, their action manifesting itself to a greater extent with respect to the K+-dependent conformant transitions. The influence of antidepressants is close to that of the neuroleptics, although it is noticeably less intensive (78--46 per cent). The action of hypnotics (barbituric acid derivatives) and of antiepileptic drugs of a different chemical structure closely approaches, but is different from the effect of neuroleptics and antidepressants, both as concerns its intensity and the lack of any essential differences in the action upon the Na+- and K+-dependant conformant transitions.

Adenylate deaminating activity was stimulated in the liver mitochondria of rats in vivo not only by serotonin or synthetic indolylalkylamines, but also by phenyl- and imidazolalkyamines. Actinomycin D and cycloheximide protein biosynthesis inhibitors prevented stimulation of adenylate deaminating activity. Theophylline, phosphodiesterase inhibitor, produced a similar effect only when the extent of stimulation of adenylate deaminating activity was comparatively high.

The rates of respiration in the presence of ADP and of phosphorylation as an ATP-ase activity of rat liver mitochondria was inhibited was in vitro by morphine with Ki=6.5 mM. The uncoupler-stimulated respiration of the mitochondria and the activity of ATP-ase and synthesis of ATP in the submitochondrial particles were not altered in the presence of morphine. It is suggested that morphine inhibited the adenine nucleotide transport through the mitochondrial membrane

The action of estradiol dipropionate (250 microgram/kg) and of phenobarbitone-sodium salt (80 microgram/kg) was studied in separate and combined (a single injection of estradiol-dipropionate after a 4-day administration of the phenobarbital-sodium salt) administration. There was an increase in the H3-phenylalanine incorporation into the cell-free protein-synthesizing system by 86% in comparison with control ovariectomized group. Under these conditions estradiol-dipropionate increased the incorporation of the labeled amino acid by 53%. A combined administration of the estrogen and of the barbiturate was not accompanied by the summation of the given effect. There was revealed a correlation between the increase in the rate of the H3-phenylalanine incorporation in vitro and an increase in the content of the cytochrome P-450 in vivo in the microsomes of hepatocytes in separate and combined administration of the preparations. The role of phenobarbitone-sodium salt as an activator of estradiol metabolism in the hepatocytes is discussed.

Activity of transketolase, an enzyme of the pentose cycle and fructosodiphosphataldolase, an enzyme of glycolisis was studied in the dynamics of development of the nystatin-producing organism and its inactive mutant under various conditions of their cultivation with a purpose of finding relation between the antibiotic production and general metabolism of Act. noursei. The transketolase activity of the organism was 2-4 times higher than that of the inactive mutant. Addition of 8000 Units/ml of nystatin to the medium markedly suppressed (50-100 per cent) the aldolase activity, however it had no effect on the transkelotase activity. Possibly the antibiotic accumulated in the mycelium played the role of a regulator of the activity of the enzymes, directing the metabolites along the hexosomonophosphate pathway of carbohydrate dissimilation.

The composition of two protosubtilins -- proteolytic enzymes of the enzymes isolated from submerged cultures of two Bacillus subtilis strains was investigated. Each of the preparations contained two proteinases that differed in their pH optimum. Conditions of chromatographic separation of two proteinases on CM-52 cellulose were tested. With the use of specific inhibitors and specific substrates it has been shown that one of the proteinases belongs to metal enzymes and is inhibited by ethylene diamine tetracetate (EDTA). Another proteinase, which is probably serine proteinase, is inhibited by diazopropine fluorophosphate (DFP). The isoelectric point of neutral proteinase is 8.15-8.20.

The activity of the enzymes of the citric acid cycle, glycolysis, and hexose monophosphate pathway was studied during germination of the spores of Bacillus anthracoides and upon their treatment with calcium hypochlorite. No activity of isocitrate dehydrogenase and glucose-6-phosphate dehydrogenase was found in the extracts of the vegetative cells, contrary to the spores and initiated spores. The activity of other enzymes changes but slightly in the course of germination of the spores. Treatment of the spores with calcium hypochlorite inhibited their initiation and germination and the activity of several enzymes, especially malate dehydrogenase, isocitrate dehydrogenase, and fumarase.

The influence of methods of cell disintegration of Bac. polymyxa on aspartate kinase activity (EC 2.7.2.4) was examined. The disruption by means of the Hews press yielded a more active preparation as compared with ultrasonic disintegration. The supernatant treatment with streptomycin sulphate increased the preparation activity 2-fold. Dialysis of the fraction with a high activity of aspartate kinase inactivated the enzyme by 80--85%. The relationship between the aspartate kinase activity and the portein and ATP concentration in the reaction mixture was established.

In liver tissue of rats, a conventional laboratory food of which was substituted for galactose-rich food, the galactokinase activity was increased, but the glucokinase was not affected. In the rats kept on a glucose-rich food the glucokinase (but not the galactokinase) was activated. Hydrocortisone injection induced an increase in tyrosine aminotransferase, but the galactokinase activity was not altered. The data obtained suggest that in rat liver tissue the galactokinase was specifically induced under the effect of galactose. Except for the liver tissue, galactose induced galactokinase in eye crystalline lens; the enzyme activity was not altered in spleen and kidney.

Staphylococcus aureus, a laboratory strain 209-P and strain I isolated freshly from infected wounds, as well as lincomycin hydrochloride, ampicillin, oxacillin and methicillin manufactured in the USSR and cephaloridin manufactured by "PLIVA" in Yugoslavia were used. Various activity levels of desoxyribonuclease and lecitinase of the staphylococci depending on sensitivity or resistance of the test-microbe to the antibiotics were shown. The activity of the above microbial enzymes characterizing the pathogenic properties decreased with development of the antibiotic resistance, sometimes to complete inactivation of the enzymes synthesized by the staphylococci. In spite of closeness of their modes of action the semisynthetic penicillins had a differentiating effect on the above enzymes.