Low-molecular-weight metabolites relevant to ethanol metabolism: correlation with alcohol withdrawal severity and utility for identification of alcoholics.

The blood levels of ethanol, acetaldehyde, acetate, methanol, acetone, lactate, pyruvate, and glucose were measured in 23 male alcohol-dependent patients on days 2 to 6 after hospitalization and in 22 healthy male blood donors. Correlations between the biochemical parameters and 17 symptoms of the alcohol-withdrawal syndrome (AWS) were calculated. Abnormally high levels of ethanol, methanol, acetate, and acetone as well as hypoglycaemia were found on day 2, but lactacidaemia and pyruvataemia were pronounced throughout the observation period. AWS severity correlated positively with the acetone content on day 2 and with the acetate content on days 2 to 6. Negative correlations were found between ethanol levels and craving for alcohol, methanol levels and craving for alcohol, and between psychopathologic disorders and the total AWS severity score. The results suggest that concentrations of blood ethanol, methanol, acetate, and acetone exceeding their normal endogenous levels can be used only as indicators of recent heavy drinking. Linear discriminant analysis using the levels of the nine parameters studied enabled the correct classification of 91% to 96% of alcoholic patients during 1 week of abstinence and 100% of control subjects. The most informative parameters in the discrimination between alcoholics and controls were lactate, pyruvate, the lactate/pyruvate ratio, acetate, and acetone.

[Endogenous ethanol in the blood and tissues of rats with hypobaric hypoxia]. / Endogennyi étanol krovi i tkanei krys pri gipobaricheskoi gipoksii.

Albino male rats weighing 160-180 g were used to study the effect of short-term hypobaric hypoxia (ascent in an altitude chamber to 2500 m and 5000 m for 1 hr) on endogenous ethanol measured in blood, brain and liver; simultaneously enzymes responsible for ethanol and acetaldehyde metabolism were determined. Endogenous ethanol in blood and tissues was found to be a very sensitive marker of hypoxia which was not correlated with lactate, pyruvate, lipid peroxidation or 11-hydroxycorticosteroids. The latter parameters varied in response to severe hypoxia.

[Comparative evaluation of the action of oxythiamine and its derivatives on animals with Erhlich's ascitic cancer]. / Sravnitel'naia otsenka deistviia oksitiamina i nekotorykh ego proizvodnykh na zhivotnykh s astsitnym rakom Erlikha.

It is found that hydroxythiamine ester with sebacic acid surpassed hydroxythiamine in its antitumour effect on Ehrlich ascites tumour in albino mice. A linear correlation is observed between the values of activity coefficients of hydroxythiamine and its esters with dicarboxylic acids and some morphometric data.

[Biochemical changes in the rat immunocompetent organs during oxythiamine involution of the thymus]. / Biokhimicheskie izmeneniia v immunokompetentnykh organakh krys pri oksitiaminovoi involiutsii timusa.

Oxythiamine injections to rats (400 mg/kg of body mass, subcutaneously, 2 injections with 48 hrs interval) caused 70% involution of thymus within 72 hrs after the first injection. The transketolase activity was inhibited by 70%, that of glucose-6-phosphate dehydrogenase by 15%, while the aldopentose level was decreased by 56% in the thymus. Inhibition of DNA and RNA synthesis was directly dependent on the dose and duration of the oxythiamine effect on the gland. Reduction of transketolase activity was accompanied by an adaptive; increase in glucose-6-phosphate dehydrogenase activity as well as by a decrease in levels of nicotinamide coenzymes (NAD, NADP) in spleen.

[Lactate and pyruvate metabolism in the tissues of rats with Walker carcinosarcoma injected with oxythiamine]. / Obmen laktata i piruvata v tkaniakh krys s kartsinosarkomoi Uoker pri vvedenii oksitiamina.

The levels of L-lactate and pyruvate as well as the enzymes of their conversion (lactate dehydrogenase in direct and reverse reactions, pyruvate dehydrogenase, pyruvate kinase, alanine transaminase) have been studied simultaneously in the liver and skeletal muscle of rats bearing carcinosarcoma Walker 256, control animals and after additional oxythiamine administration. Properties of oxythiamine independent of its anticoenzymic activity manifest themselves in the body of tumour-bearing animals to a greater extent. After the antivitamin administration there occur strong inhibition of pyruvate kinase, activation of alanine transaminase, normalization of the L-lactate level in the tissues.

Transketolase, pyruvate and oxoglutarate dehydrogenase activities and [14C]thiamin turnover in tissues of mice fed thiamin-deficient diet.

A study was made of turnover of [14C]thiamin (5 or 2 micrograms/mouse) in mice fed a thiamin-deficient diet. Simultaneously the activities of the thiamin-dependent enzymes (transketolase, pyruvate and oxoglutarate dehydrogenases) were measured as an index of efficiency of fulfilling the coenzyme function of the vitamin under conditions of different thiamin status. After [14C]thiamin injections of 5 micrograms/mouse, kidney, spleen, stomach and pancreas tissue stores turned over completely on day 9, whereas by day 13 this process had not yet been finished in liver, heart and brain. On administration of 2 micrograms [14C]thiamin/mouse, turnover of the tissue stores proceeded at a slower rate. The tissue transketolase activity decreased after the 2-microgram injections as compared to that in the mice administered 5-microgram injections. With 2 micrograms of [14C]thiamin, the pyruvate dehydrogenase activity lowered gradually in all the tissues studied, whereas the oxoglutarate dehydrogenase decreased in liver and kidneys. The pattern of the depression of the thiamin-dependent enzyme activities after the 2-microgram [14C]thiamin injections suggests a regularity in the vitamin redistribution in different organs and subcellular fractions.

Thiamine metabolism in the liver of mice with Ehrlich ascites carcinoma.

Thiamine pyrophosphate (TPP) content, activities of thiamine pyrophosphokinase (TPKase), thiamine pyrophosphatase, transketolase (TK), pyruvate (PDG) and oxoglutarate dehydrogenases (OGDG) were measured in the liver and cells of Ehrlich ascites carcinoma (EAC) on the 5th, 10th and 15th day after transplantation of the tumor to mice fed a thiamine-deficient diet. The TPP level gradually decreased in the liver of tumor-bearing mice but remained constant in tumor cells (1.06 +/- 0.02 microgram/g tissue). Deprivation of dietary thiamine lowered the liver TPP level even to a greater extent, and subsequent daily 10 micrograms thiamine/mouse injections did not restore it. The TPKase activity in the liver of mice with EAC decreased by 24% and in thiamine deficiency, by 44%. The liver PDG, OGDG and TK activities were reduced but slightly in mice with EAC, whereas thiamine deprivation resulted in a decrease of the enzyme activities: PDG by 60%, OGDG by 25% and TK by 45%. TK activity in tumor cells was 90 mumol S-7-P/g tissue/h, and the TPP effect amounted to 24%. Thiamine deprivation decreased the TK activity by 45% and raised the TPP effect up to 180%. Thiamine injections restored the TK activity in tumor cells and reduced the TPP effect.

[Lactate level in the tissues of animals with a tumor administered oxythiamine and the properties of lactate dehydrogenase]. / Uroven' laktata v tkaniakh zhivotnykh s opukhol'iu pri vvedenii oksitiaminina i nekotorye svoistva laktatdegidrogenazy.

Content of lactate in blood, liver and kidney tissues, skeletal muscle and in tumor tissue as well as some properties of lactate dehydrogenase (LDH), isolated from liver tissue, were studied in three groups of rats - intact rats, the tumor-bearing animals with sarcoma S-45 and the tumor-bearing rats treated with hydroxythiamin within 22 days. In skeletal muscle on the side of the tumor localization content of lactate was decreased as compared with the opposite side of the body. As shown by analysis of correlation between the content of lactate and the tumor weight and the lactate concentration in the tumor-bearing rat tissues studied, the tumor appears to be responsible for consumption but not for production of lactate. Hydroxythiamin altered distinctly the ratio of lactate content in various tissues and normalized the liver tissue LDH isoenzyme spectrum in tumor-bearing rats; the vitamin decreased 9- and 15-fold the enzyme specific activity in oxidation of lactate in presence of NAD+ and NADP, respectively. After the hydroxythiamin treatment the apparent KM value of the enzyme, isolated from the tumor-bearing rat liver tissue, was increased with pyruvate and decreased with lactate as substrate.

Effect of thiamine deprivation on thiamine metabolism in mice.

Mice were made deficient by thiamin deprivation. Thiamin pyrophosphokinase and thiamin pyrophosphatase activities were measured, and their changes were compared to transketolase (TK), pyruvate and alpha-ketoglutarate dehydrogenase (DG) activities and thiamin pyrophosphate (TPP) level in the same tissues. Thiamin pyrophosphokinase activity was increased on day 10 of thiamin deficiency and remained unchanged within the next period of investigation. Thiamin pyrophosphatase activity decreased after 5 days and was enhanced in 10, 15 and 20 days of deficiency. This fact may be related to the regulatory role of the enzyme in the intertissue vitamin distribution and transport. The liver TPP level was the earliest and most specific indicator of the thiamin status as thiamin deficiency developed, and pyruvate DG was more drastically inhibited than alpha-ketoglutarate DG. Blood TK was more sensitive to thiamin deprivation than liver TK. In both cases we obtained a more (20-40% in blood) or less (5-10% in liver) pronounced TPP-stimulatory effect of transketolase activity.

[Features of pyruvate and lactate metabolism in tumor-bearing rats following citrate administration]. / Osobennosti obmena piruvata i laktata u krys-opukholenositelei pri vvedenii im tsitrata.

Everyday administration of citrate (250 mg/kg of body mass) into healthy rats within 4 days inhibited activities of pyruvate kinase, pyruvate dehydrogenase, alanine transaminase and of reverse lactate dehydrogenase in liver tissue but not in sceletal muscles. Within the longer period of citrate administration (8 or 12 days) activities of pyruvate dehydrogenase and alanine transaminase continued to decrease in liver tissue, at the same time, content of pyruvate proceeded to increase in sceletal muscles. More distinct inhibitory effect of citrate on the pyruvate dehydrogenase activity was observed not only in liver tissue but and in sceletal muscles of tumor-bearing animals. Alanine transaminase, which was inactivated in liver tissue of healthy animals after citrate treatment, was markedly activated in tumor-bearing rats in the same conditions. The data obtained suggest that some regulatory functions of citrate were qualitatively transformed in tumor-bearing animals, mainly, in relation to turnover of glucogenic amino acids.

[Effect of oxythiamine on pyruvate and lactate metabolism in rat tissues]. / Vliianie oksitiamina na obmen piruvata i laktata v tkaniiakh krys.

The ratio of two substrates (pyruvate and lactate), activity of enzymes, responsible for their turnover in liver tissue, sceletal muscles and blood, were studied simultaneously in experiments on the effect of hydroxythiamin, which was administered at doses, causing a state of hypovitaminosis B1. Hydroxythiamin was shown to inhibit specifically the activity of thiamin-dependent enzymes (transketolase and pyruvate dehydrogenase). It affected also the metabolism of triose phosphates, pyruvate and lactate. At the same time, hydroxythiamin was responsible for changes in activities of other enzymes, participating in turnover of the substrates studied.

[Thiamine and pyruvate metabolism in tumor-bearing rats]. / Tiamin i obmen piruvata u krys-opukholenositelei.

Correlation between pyruvate and lactate contents as well as between enzymes participating in turnover of the substrates (pyruvate- and lactate dehydrogenases, alanine aminotransferase, pyruvate kinase) were studied in rat liver tissue simultaneously with tumor growth and intensive thiaminotherapy. Thiamine, administered into rats carrying carcinosarcoma Woker-256 at a daily dose 12.5 mg/kg body weight, exhibited the normalizing effect on activity of enzymes studied, on quantitative content of LDH isoenzymes and on content of lactate in blood and of pyruvate in liver tissue. Possible effect of thiamine on pyruvate metabolism in tumoral impairment is discussed.