Effect of α-Tocopherol on Endotoxicosis

The effect of α-tocopherol in endotoxicosis was studied. The α-tocopherol level significantly decreased in mouse liver 18 hr after endotoxin administration, thereafter tending to increase to approach the normal range. In endotoxin-tolerant mouse liver, the lipid peroxide level was reduced to less than half of that in nontolerant animals following endotoxin challenge. The liver lipid peroxide level and serum lactate dehydrogenase or acid phosphatase leakage were studied in mice fed a vitamin E-deficient (ED) diet and a vitamin E-supplemented (ES) diet for 40 days. ED mouse liver exhibited a higher formation of lipid peroxide after endotoxin was given while there was a markedly lower level in ES mouse liver. There was significantly more serum lactate dehydrogenase or acid phosphatase leakage in ED mice than in ES mice after endotoxin administration. There was about a 25% decrease in liver superoxide dismutase (SOD) activity in endotoxin-poisoned mice fed both the normal and the ED diets, while the activity was at a higher level in ES-fed mice. These results suggest that α-tocopherol may be helpful in preventing membrane instability in endotoxin poisoning.     

Lactate dehydrogenase isozyme patterns in the denervated quail (Coturnix coturnix japonica) muscles

Polyacrylamide gel electrophoresis of the Japanese quail (Coturnix cotunix japonica) muscle extracts revealed a single lactate dehydrogenase isozyme. A month after surgical unilateral brachiotectomy (denervation) there was significant atrophy of the triceps, biceps and radius ulnar muscles accompanied by the appearance of an additional lactate dehydrogenase isozyme band. This extra band may be the result of the synthesis of a new lactate dehydrogenase isozyme. This new isozyme exhibited a lower affinity for lactate, less sensitivity to urea denaturation and was more thermostable than the lactate dehydrogenase of normal (innervated) quail muscles. Based on these properties, it is suggested that the newly synthesised isozyme of the denervated muscles is LDH-1, (or B4/H4) type. Brachiotectomy also resulted in significant quantitative changes in the total lactate dehydrogenase activity of innervated muscles of the same animal.     

2,3,7,8-tetrachlorodibenzo-p-dioxin induced alterations of pyruvate carboxylase levels and lactate dehydrogenase isozyme shifts in C57BL/6J male mice

A dose-dependent reduction of hepatic pyruvate carboxylase levels and activity occurs in C57BL/6J male mice given 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) i.p. in a corn oil carrier. The dose range was from 1 to 75 μg/kg body weight and the analysis was done 8 days postinjection. At the maximum TCDD level investigated, we found a 10-fold reduction in pyruvate carboxylase activity. Furthermore, TCDD at a dose of 1 μg/kg body weight blocks corn oil induction of an increase in the amount of pyruvate carboxylase in liver protein extracts. At doses beyond those required to initiate a reduction in pyruvate carboxylase, lactate dehydrogenase isozyme patterns shift. This is accompanied by an increase in blood lactic acid levels. We propose that TCDD-mediated reduction in pyruvate carboxylase and lactate dehydrogenase isozyme shifts may represent a major component in TCDD toxicity.     

Spleen lipids: effect of whole body gamma irradiation and radioprotective chemicals

Effect of whole body gamma irradiation (1200 r) on spleen lipid metabolism of male and female rats 24 hrs and 48 hrs after irradiation and the effect of radioprotective chemicals vis. AET, serotonin, their mixture and cystamine on radiation induced changes in spleen lipid metabolism has been studied. In male rats both 24 and 48 hrs after irradiation a significant increase in spleen total lipids, cholesterol, phospholipids, phosphatidylethanolamine and phosphatidylcholine was observed. Administration of AET before irradiation prevented the changes in spleen total lipids and cholesterol but not in phospholipids, which was prevented by prior administration of both serotonin and the mixture of serotonin and AET. In female rats 24 hrs after irradiation only spleen total lipids showed an increase which was prevented by prior administration of cystamine. In male rats, 24 hrs after irradiation the incorporation of NaH2 32PO4 (counts/min/ug PLP and counts/min/g spleen) into spleen total phospholipids, phosphatidylcholine and phosphatidylethanolamine was reduced and this was corrected by prior administration of AET. Serotonin and the mixture of serotonin + AET did not protect the specific activity of phosphatidy choline. In female rats irradiation increased the incorporation of NaH2 32PO4 into phosphatidylcholine, which was not prevented by prior administration of cystamine. The fatty acid composition of spleen lipid of female rats was profoundly altered 24 hrs after irradiation. Palmitic acid and oleic acid showed an increase whereas arachidonic and fatty acid above arachidonic acid showed an decrease, which were corrected by administration of cystamine before irradiation.     

Investigation of the possible protective role of gallic acid on paraoxanase and arylesterase activities in livers of rats with acute alcohol intoxication

Gallic acid, a polyphenyl class natural product from gallnut and green tea, is known to be antioxidant, anti‐inflammatory and radical scavenger. In this study, we aimed to investigate the possible protective effects of gallic acid on paraoxonase and arylesterase activities in liver exposed to acute alcohol intoxication. Paraoxonase and arylesterase activities in liver tissue and serum aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase levels were measured. Histological investigations were also made. In our study, we observed a significant increase of serum alanine aminotransferase, aspartate aminotransferase and lactate dehydrogenase activities, which are indicators of liver damage after acute ethanol consumption. Gallic acid therapy has significantly reduced the increase in these biomarkers, indicating a possible hepatoprotective effect of gallic acid. Ethanol consumption caused a significant decrease in liver paraoxonase activity (P < 0.001). Gallic acid treatment partly restored this decreased paraoxonase activity, which resulted from ethanol administration. A gallic acid dose of 100 mg/kg was observed as highest restoring effect for paraoxonase activity (P < 0.05). The activity of arylesterase was decreased in the ethanol group as compared with the control group, but this was not significant. However, 50 mg/kg of gallic acid treatment restored the loss of this activity due to ethanol exposure (P < 0.001). We observed that gallic acid ameliorates the liver damage caused by excessive alcohol consumption in a dose‐dependent way. Our results in this study showed that gallic acid might have a protective effect against alcoholic liver disease. Copyright © 2012 John Wiley & Sons, Ltd.     

Metabolical changes induced by chronic phenol exposure in matrinxã Brycon cephalus (teleostei: characidae) juveniles

Phenol and its derivatives are xenobiotics present in many industrial wastewaters and in non-specific pesticides. It is a lipophilic compound and, therefore, accumulates along the trophic chain. Phenol is often found in marine and fresh water environments. The aim of this work was to detect metabolic changes induced by phenol in Brycon cephalus juveniles. Several enzymes activities and metabolites were quantified in the liver, white muscle and plasma. Among the enzymes assayed are alanine and aspartate amino transferases (ALAT and ASAT), lactate dehydrogenase (LDH) and malate dehydrogenase (MDH). Glucose, glycogen, lactate, ammonia and pyruvate were also quantified in tissues and plasma (glycogen in tissues only). The liver was the most responsive organ. The activities of the transaminases increased in muscle and liver, followed by an increase in hepatic ammonia. Correlation between ammonia and transaminases points towards phenol-induced consumption of protein. Hepatic glycogen and glucose contents were lower followed exposure to phenol. The same was observed for muscle glucose, suggesting considerable use of carbohydrate stores. The activity of hepatic lactate dehydrogenase increased with negative correlation with muscle lactate. This suggests that hepatic gluconeogenesis supplies tissues like muscle and brain with glucose. These results indicate that phenol intoxication demands metabolic energy and leads to significant changes of the metabolic profile of the fish, inducing to a certain extent a shift from carbohydrate catabolism to protein catabolism and the activation of gluconeogenesis.     

Histochemical and electron microscopical studies of skeletal muscle affected by gas gangrene.

Ultrastructural and histochemical changes of skeletal muscle were studied in three patients affected with gas gangrene. There was complete lack of the phosphorylase, succinate dehydrogenase and adenosine triphosphatase activities in the affected muscles of all the patients. In unaffected muscles these enzymes showed weaker activities than in norm. The lactate dehydrogenase activity, especially the heart type isozyme (LDH-1 or H4) proved less sensitive to the effect of clostridial toxin. A general increase in the acid phosphatase activity was found both in affected and in unaffected muscles. On electron microscopic examination damage to sarcolemmal membrane and disintegration of myofilaments was seen. The mitochondria were swollen and their cristae distorted and fragmented.     

Effect of thyroxine on the lactate dehydrogenase isoenzyme composition of chicken tissues in ontogeny

Using disc electrophoresis in polyacrylamide gel, studies have been made on the content of isoenzymes of lactate dehydrogenase in the mitochondria and cytoplasm from the brain, heart and liver after thyroxine administration to embryonal, early postnatal and adult hens. After this administration, the isoenzymic composition becomes more complex, redistribution of separate isozymes being observed in ontogenesis. The level of aerobic form of LDH increases at early stages of ontogenesis, that of anaerobic ones--in adult birds. Basing on their different functional role due to the presence of H- and M-subunits, it may be suggested that thyroxine administration results in a compensatory increase of the oxidative or glycolytic processes at the corresponding stages of ontogenesis, these changes reflecting phylogenetic peculiarities of the formation of the hormonal control of lactate dehydrogenase in tissues of birds.     

Pyruvate kinase activity and gluconeogenesis in RAT liver after glycogen depletion with nicotinic acid

Summary Nicotinic acid administration, which depletes liver glycogen, leads to an increase of both pyruvate kinase L and phosphoenolpyruvate carboxykinase in liver by a factor of nearly two. The former is not prevented by either cycloheximide or actinomycin D. L-Cysteine, an allosteric inhibitor of pyruvate kinase L, favors gluconeogenesis from lactate in both nicotinic acid treated and starved animals.     

Activities of enzymes concerned with pyruvate and oxaloacetate metabolism in the heart and liver of developing sheep.

1. In order to assess whether the potential ability of heart ventricular muscle and liver to metabolise substrates such as alanine, aspartate and lactate varies as the sheep matures and its nutrition changes, the activities of the following enzymes were determined in tissues of lambs obtained at varying intervals between 50 days after conception to 16 weeks after birth and in livers from adult pregnant ewes: lactate dehydrogenase (EC 1.1.1.27), alanine aminotransferase (EC 2.6.1.2), pyruvate kinase (EC 2.7.1.40), pyruvate carboxylase (EC 6.4.1.1), phosphoenolpyruvate carboxykinase (GTP)(EC 4.1.1.32), malate dehydrogenase (EC 1.1.1.37), aspartate aminotransferase (EC 2.6.1.1) and citrate (si)-synthase (EC 4.1.3.7). 2. In the heart a most marked increase in alanine aminotransferase activity was found throughout development. During this period the activities of citrate (si)-synthase, lactate dehydrogenase and pyruvate carboxylase also increased. There were no substantial changes in the activities of aspartate aminotransferase, malate dehydrogenase or pyruvate kinase. Pyruvate kinase activities were five times greater in the heart compared with those found in the liver. No significant activity of phosphoenolpyruvate carboxykinase (GTP) was detected in heart muscle. 3. In the liver the activities of both alanine aminotransferase and aspartate aminotransferase increased immediately following birth although the activity of alanine aminotransferase was lower in livers of pregnant ewes than in any of the lambs. As with alanine aminotransferase the highest activities of lactate dehydrogenase were found during the period of postnatal growth. No marked changes were observed in malate dehydrogenase or citrate (si)-synthase activities during development. A small decline in pyruvate kinase activity occurred whilst the activities of pyruvate carboxylase and phosphoenolpyruvate carboxykinase (GTP) tended to rise during development.     

Plant Leaf and Stem Proteins. II. Isozymes and Environmental Cabbage

The activity of 10 enzymes separated by acrylamide disc gel electrophoresis of leaf and stem extracts from Dianthus grown under summer and winter conditions was studied. While banding was constant and highly reproducible under each environment, differences between the 3 cultivars and between the tissues were evident. No significant differences in the isozyme patterns of glutamate dehydrogenase, 6-phosphogluconate dehydrogenase, glucose-6-phosphate dehydrogenase, malate dehydrogenase, and catalase were observed between the 2 environments. Loss of activity was observed under winter conditions with amylase and lactate dehydrogenase and loss of certain isozymic components was evident with acid phosphatase and esterase. Prominent changes were observed in peroxidase isozymes, the hardy cultivars developing additional isozymic components under winter conditions. Only minor changes in the total protein banding were seen. The enzymes showed considerable stability in those tissues killed by the freezing conditions.     

Interaction of H2-receptor antagonists, cimetidine and ranitidine with microsomal drug metabolizing and other systems in liver.

Cimetidine has been demonstrated to impair microsomal oxidative drug metabolizing and other enzyme systems in mouse liver. The inhibition is rapid, occurring after a single administration and also found to be dose-dependent. It is more significant after daily administration for 15 days. Enzyme inhibition by ranitidine, another H2-receptor antagonist was comparatively less at all the concentrations of the drug tested. An increased activity of alkaline phosphatase, glutamate-pyruvate and glutamate-oxaloacetate transaminase was observed in liver with cimetidine administration, whereas that of lactate and succinate dehydrogenase was inhibited only after administration of 2000 mg cimetidine per kg body weight. Except alkaline phosphatase other enzymes were unaffected after ranitidine administration. Analysis of lipid classes in liver showed that phospholipid, triglycerides and free fatty acid contents were significantly decreased in drug administration while cholesterol level showed very little or no change. Microsomal and soluble protein contents were significantly increased which probably indicate that the inhibition in the enzyme activity by histamine H2-receptor antagonists may be a lipid mediated process and not resulted from the reduced availability of the enzyme protein.     

Hypoxic metabolism in wild rice (Zizania palustris): enzyme induction and metabolite production

Alcohol dehydrogenase (ADH, EC 1. 1. 1. 1), lactate dehydrogenase (LDH, EC 1. 1. 1. 27) and alanine aminotransferase (AlaAT, EC 2. 6. 1. 2) activity in wild rice ( Zizania palustris L.) root tissue increased after 4 days of exposure to hypoxic stress. The activities of ADH and AlaAT also increased in leaf tissue under these same conditions, whereas LDH activity did not. Isozyme banding patterns indicate that wild rice has at least two functional Adh genes, only one of which is hypoxically induced in root and leaf tissue. The isozyme profile of LDH also indicates the presence of two functional Ldh genes in wild rice. Two bands of AlaAT activity are visible on native electrophoretic gels of root and leaf tissue. Neither of these bands appears to increase in activity in hypoxic samples, even though spectrophotometric assays indicate an increase in AlaAT activity. Ethanol accumulation was the highest of all the metabolites measured. Alanine and malate also accumulated under hypoxic conditions but only to about one-fifth the level of ethanol. Succinate, aspartate and lactate showed no observable changes throughout the induction period. These results show that wild rice differs from domesticated rice ( Oryza sativa L.) in its metabolic responses to anaerobic stress. The possible role of these responses in conferring flood tolerance is discussed.     

Perturbations in carbohydrate metabolism during cypermethrin toxicity in fish, Tilapia mossambica

Sublethal concentrations (0.04 ppm) of cypermethrin induced significant metabolic changes in brain, liver and gill tissues of fish, T. mossambica. While cypermethrin caused depletion in glycogen and pyruvate levels lactate content was elevated in all the tissues. While phosphorylase 'a' and aldolase activity increased, phosphorylase 'b' activity registered a decrease in the present study. A decrease in lactate dehydrogenase activity with increase in lactate levels suggests reduced mobilization of pyruvate into citric acid cycle. Glucose-6-phosphate dehydrogenase activity was also elevated indicating enhanced oxidation through HMP pathway during cypermethrin toxicity. Inhibition of succinate, malate and isocitrate dehydrogenases and cytochrome c oxidase activity indicates impaired oxidation of carbohydrates through citric acid cycle.     

Changes in lactate dehydrogenase activity in chicken tissues in hyperthyreosis in ontogenesis

The lactate dehydrogenase activity in reactions of lactate oxidation and synthesis was studied in subfractions of the chicken brain, heart and liver at the embryonal, early postembryonal and adult stages of development after thyroxine administration. It has been shown that during embryogenesis thyroxine predominantly enhanced the rate of lactate oxidation in the mitochondrial tissues. A marked increase in the lactate synthesis was found in cytoplasm of the adult chicken tissues. Specificity of enzyme activity alterations was detected in the chicken brain during ontogenesis after thyroxine administration.     

Effect of thyroid hormone on peroxisomal flavin enzymes in rat liver and kidney

The effect of thyroid hormone on peroxisomal enzyme activity was studied in thyroidectomized- and T4-administered-thyroidectomized rats. In liver, the activities of isozyme A of L-alpha-hydroxyacid oxidase, D-amino acid oxidase, urate oxidase and catalase were decreased by thyroidectomy, and the diminished enzyme activities were restored by T4 administration to rats. These modifications induced by thyroidectomy or by T4 administration, however, were prominent only in immature animals (20-day-old rats). Although the changes in-alpha-hydroxyacid oxidase and D-amino acid oxidase activities, induced by thyroidectomy or by T4 administration, were also observed in 40-day-old rats, those in urate oxidase and catalase activities were not significant in 40-day-old rats. Acyl CoA oxidase activity was not affected by thyroidectomy or by T4 administration in either 20- or 40-day-old rats. In the kidney, isozyme B of L-alpha-hydroxyacid oxidase activity was reduced by thyroidectomy and the diminished enzyme activity was restored by T4 administration in both 20- and 40-day-old rats. D-Amino acid oxidase and catalase activities in kidney, however, were not significantly modified by thyroidectomy or by T4 administration in either 20- or 40-day-old rats. The results suggest that thyroid hormone can modify the peroxisomal enzyme activity, which is prominent in immature animals.     

In vivo effect of 2-deoxy-D-glucose on glucose-6-phosphate dehydrogenase activity in the cytosol of liver, heart and skeletal muscle of rats

2-deoxy-D-glucose (2-DG), the unmetabolizable analogue of glucose induces a series of metabolic, hormonal and behavioral responses, causing cellular glucoprivation. According to in vitro studies, 2-DG inhibits phosphofructokinase in cultured human cells. The present investigations deal with changes in the cytosolic glucose-6-phosphate dehydrogenase activity following in vivo 2-DG administration. A single dose of 2-DG (600 mg/kg) has no influence on the activity of glucose-6-phosphate dehydrogenase in the cytosol of liver, heart and skeletal muscle of the rat. The concomitant increase in serum glucose, lactate and FFA concentrations observed in the study indicates indirectly a stimulation of adrenergic system. After three days of successive administration of 2-DG to rats, dehydrogenase activity decreased in the liver by approx 57% and in the skeletal muscle by approx 82% in comparison with control animals. Moreover the in vivo effect of 2-DG was found to be fully reversible, probably when the total amount of the inhibitor was excreted.     

Lactate dehydrogenase changes following several cardiac hypertrophic stresses.

The effects of four different cardiac hypertrophic stresses on cardiac lactate dehydrogenase (LDH) isozyme composition and activity were examined. Altitude-induced right ventricular hypertrophy was accompanied by an increase of 10% in the M subunit of LDH in right ventricle, left ventricle, and atria. Left ventricular hypertrophy induced by aortic stenosis also produced isozyme changes in the ventricles, but of only half the magnitude. Biventricular hypertrophy, induced by running or swimming, was accompanied by 4-5% increases in M LDH in the ventricles only. We conclude that changes in LDH activity are directly related to changes in the M subunit in all three portions of the heart. No changes in H subunit were noted under any of the stresses. It appears that the magnitude of changes in cardiac LDH isozyme composition are only marginally related to extent of hypertrophy.     

Genetics and ontogeny of aldehyde dehydrogenase isozymes in the mouse: Evidence for a locus controlling the inducibility of the liver microsomal isozyme

Variation in the inducibility of the liver microsomal isozyme of aldehyde dehydrogenase (designated AHD-Cy) by phenobarbital administration was observed among inbred strains and linkage testing stocks of Mus musculus. The phenotypes were inherited in a normal Mendelian fashion with two alleles showing codominance at a proposed regulatory locus (designated Ahd-3r). Strain variation was also observed for the induction of liver AHD-Cy by 17-β-oestradiol administration to ovarectimized female mice. Moreover, this enzyme was elevated in activity by the administration of high (nonphysiological) levels of progesterone. Development studies showed that the liver and kidney AHD-Cy isozyme exhibited low activities in late-stage fetal and neonatal mice and reached adult levels by approximately 6 weeks of age.     

Enzyme histochemical changes in retinal ganglion cells and the optic nerve after goldfish optic nerve lesion. A regenerative and hypertrophic phenomena study

After sectioning of the goldfish optic nerve a number of enzyme histochemical changes are observed in the hypertrophied retinal ganglion cells and in the optic nerve. Between one and eighteen days postoperatively an increase in the amount of acid phosphatase reaction product is noted. The enhanced activity decreased to normal first in the optic nerve, followed by the optic tract and tectum. Four days postoperatively higher levels of activity were noted in the hypertrophic retinal ganglion cells for the enzymes NADH tetrazolium reductase, cytochrome oxidase, glutamate dehydrogenase and lactate dehydrogenase. The same enzymes also showed an activity increase in the lesioned optic nerve after four to ten days postoperatively, beginning at the cut and gradually spreading towards the optic tectum. Between fifteen and eighteen days the activity dropped to normal in the hypertrophic retinal ganglion cells, while in the lesioned nerve raised levels of reaction products could be seen till days thirty-five and/or forty-five. It was concluded that the degeneration of the optic pathway is marked by the increase of acid phosphatase activity, whereas the process of regeneration is characterized by an increase of NADH tetrazolium reductase, cytochrome oxidase, glutamate dehydrogenase and lactate dehydrogenase activities. The possible functional implications of these enzymes in the regenerative phenomena are discussed.