Pyruvate kinase activity in the placentas of women living in polluted and unpolluted environments.

Background: It was shown earlier that in women living in a polluted environment, the proportion of hypotrophic newborns was greater than in the general population. The placentas of these women show significant histological changes. The authors decided to check whether the activity of pyruvate kinase (PK), a key enzyme in the third stage of glycolysis, changes similarly.

[Erythrocyte concentrations of adenosine triphosphate (ATP) and magnesium, before and after conservative therapy of lower extremities atherosclerosis].

37 patients with atherosclerosis of lower extremities and the mean claudication distance of 300-500 m (Fontaine 11 degrees) were subjected to pharmacotherapy with pentoxyfilline 600 mg twice daily, and walking exercise tests on a treadmill. The concentrations of ATP and magnesium ions in erythrocytes were assessed in the patients in resting condition, and after standardized walking exercise tests, 6 and 12 weeks since the beginning of therapy. Applied treatment proved beneficial in protecting the patients against depletion of ATP in their erythrocytes.

Tumor-specific pyruvate kinase isoenzyme M2 involved in biochemical strategy of energy generation in neoplastic cells.

The differences in properties of pyruvate kinase (EC 2.1.7.

Changes in ATP level and iron-induced ultra-weak photon emission in bull spermatozoa, caused by membrane peroxidation during thermal stress.

ATP level, cell motility and viability, oxygen uptake, pyruvate kinase activity, and ultra-weak photon emission (UPE) induced by red-ox Fe(2+)-ascorbate cycling system were studied in fresh, in previously equilibrated in a glycerol diluent, and in cryopreserved bull spermatozoa, exposed to thermal stress by incubation of the cells at 44 degrees C. A sharp drop in motility and viability of fresh spermatozoa and even more so, of equilibrated and cryopreserved cells was accompanied by accumulation of ATP. When cell movement was totally inhibited, ATP utilization was decreased, while chemical energy continued to be produced by cell pyruvate kinase, one of the key glycolytic enzymes, which in spermatozoa is very active (6500 IU/g protein) and insensitive to feed-back inhibition by excess of ATP and L-cysteine.

Effect of environmental fluorides on key biochemical processes in humans.

Several biochemical parameters connected with energy metabolism were studied in the inhabitants living in the neighbourhood of the Aluminium Smelter and in inhabitants of Chorzów, one of the most polluted towns in the Upper Silesian Industrial Region, chronically exposed to environmental fluorides and other toxic compounds. In people exposed to environmental fluorides excessive excretion of fluorides in urine was noted. This effect was connected with a decrease in urine and erythrocyte magnesium concentrations.

Effects of buthobendin and epinephrine on glycolytic energy formation and magnesium concentration in vitro and in vivo.

Buthobendin activated glycolytic lactate formation stronger than epinephrine and increased the ATP level, both in vitro in rabbit myocardial slices and in vivo in rabbit blood. These effects were accompanied by an increase in extracellular magnesium concentration, which was probably related to the inhibitory effect of buthobendin on the membrane-bound ATPases.

[Biochemical indicators of carbohydrate and energy metabolism in the Chorzów population after long-term exposure to industrial pollutants].

In three groups of Chorzów inhabitants, living in the most polluted industrial environment, elevated blood lactate and glucose levels, as well as diminished blood ATP level pointed to disturbances in carbohydrate and energy metabolism. In spite of the exposition of people studied to many toxic substances from polluted environment (fluorides, lead and others), a decrease in ATP level was less expressed than in earlier investigated inhabitants of Skawina, exposed to fluorides from the Aluminium Plant, which was probably connected with greater supply of magnesium salts from food and water.

Pyruvate kinase from cytosolic fractions of the Ehrlich ascites tumour, normal mouse liver and skeletal muscle.

Comparative studies on cytosolic pyruvate kinase (PK, EC 2.7.1.

The effect of buthobendin on glycolysis in rabbit myocardial slices in vitro.

The effect of buthobendin (2S,2'S isomer of N,N'-dimethyl N,N'-bis[1-(3',4',5'-trimethoxybenzoyloxy)-butyl-2]-ethylenediamin e dihydrochloride), (CravitenR) on aerobic and anaerobic glycolysis in rabbit myocardial slices was compared with that of the biologically inactive isomer 2R,2'R and the well-known antiarrhythmic drugs quinidine and procainamide. Only buthobendin stimulated lactate formation under anaerobic and aerobic conditions. However, that effect was not accompanied with a parallel increase in the glucose uptake, but was related to a decrease in the glycogen level.

A pyruvate kinase variant in different mouse transplanted tumors.

Mouse transplanted tumors, in contrast to normal tissues, contain a pyruvate kinase (PK) variant sensitive to the inhibitory action of L-cysteine and less sensitive to saturated fatty acids than the normal enzyme. In selected normal and tumor materials two fractions of PK were separated. Fraction A (20-30% (NH4)2SO4 saturation) dominated in normal liver, and fraction B (50-60% (NH4)2SO4 saturation) in skeletal muscles and Ehrlich ascites tumor.

The effect of levamisole on energy metabolism in Ehrlich ascites tumour cells in vitro.

It has been found that levamisole, an anthelmintic drug, used also as an immunomodulator in human cancer therapy, is a strong inhibitor of tumour aerobic glycolysis. In vitro, in Ehrlich ascites tumour (EAT) cells and supernatants it diminishes glucose uptake and lactate formation. It does not, however, exert a similar inhibitory effect on glycolytic activity in normal liver and muscle supernatants.

The inhibitory effect of various fatty acids on aerobic glycolysis in Ehrlich ascites tumour cells.

Inhibition of glycolysis in Ehrlich ascites tumour cells by saturated fatty acids, added either in form of potassium salts or incorporated into phosphatidylcholine liposomes, increases with the increasing carbon atom chain length and is independent of the concentration within the range of 0.1 to 1.0 mM.

The inhibitory effect of L-cysteine and its derivatives on glycolysis in Ehrlich ascites tumour cells.

L-Cysteine inhibits aerobic glycolysis and restores the Pasteur effect in Ehrlich ascites tumour cells or in their supernatants, while D-cysteine has no effect on this process. Other compounds which have configuration L at the alpha-carbon and a thiol group in the beta-position (penicillamine) or restore them in vivo (3-mercaptopyruvate, cystine or L-serine together with L-homocysteine) also show inhibitory properties. DL-Homocysteine with a free thiol group in the gamma-position, reduced glutathione, methionine and products of cysteine oxidation (cysteic acid, taurine) do not inhibit tumour aerobic glycolysis.

The effect of Craviten, a new antiarrhythmic drug, its 2R, 2'R isomer, quinidine and procaine amide on human platelet aggregation.

Among the optical isomers of N, N'-dimethyl-N, N'-bis[1-(3', 4', 5-trimethoxybenzoyloxy)-butyl-2]-ethylenediamine dihydrochloride only the isomer with the (2S, 2'S) configuration (Craviten) in a concentration of 0.2 microgram/ml inhibits the ADP-induced aggregation of human platelets. The (2R, 2'R) isomer and quinidine exert a similar effect but only in a concentration ten times higher.

The effect of a new antiarrhythmic drug: Craviten (M-71) on the ATP level in heart muscle slices in vitro.

Under anaerobic conditions, in which glucose is the only energy source, the ATP level in heart muscle slices diminishes to about 50% of the control value during 60 min of incubation. The presence of a new antiarrhythmic drug, Craviten (Polfa) (2S, 2'S) N, N'-dimethyl-N, N'-bis-[1(3', 4', 5'-trimethoxybenzoyloxy)-butyl-2]-ethylenediamine dihydrochloride, (M-71), and to some extent also its 2R, 2'R isomer in 10 times greater concentration protects against this spontaneous ATP fall observed anaerobically in the control experiments. Under aerobic conditions, with glucose or palmitate as energy sources, Craviten even raises the ATP level in comparison to the initial control values.