Effect of tuftsin on enzyme activity in the energy metabolism of lymphocytes

The cytochemical technique was used to measure the activity of succinate dehydrogenase (SDH), lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G-6-PDH) of peripheral blood lymphocytes of mice and rats given intraperitoneal injections of an endogenous immunostimulant tuftcin (Tre-Lys-Pro-Arg) in a dose of 0.3 mg/kg. A significant decrease of SDH activity was observed both in mice and rats 4 and 6 hours following injection, respectively. In mice, that activity returned to normal in 12, while in rats in 24 hours. An opposite action was produced by tuftcin on G-6-PDH, causing the maximum elevation of the enzyme activity in rat lymphocytes 6 hours after peptide administration. The decrease to the initial level was observed in 24 hours. Tuftcin did not affect the activity of LDH. The data obtained indicate that the immunological effect of tuftcin is coupled with the changes in the activity of Krebs cycle enzymes (SDH) and pentose phosphate cycle enzymes (G-6-PDH).     

Freeze denaturation of enzymes and its prevention with additives

Freeze inactivation of LDH, MDH, ADH, G-6-PDH, and PK and its prevention with additives such as sodium glutamate and albumin were studied. LDH, MDH, ADH, G-6-PDH, and PK, each lost their activity during frozen storage at -20 degrees C. The speed of the inactivation differed in each. The stability of the enzymes increased with the increase of the enzyme concentration. Sodium glutamate and albumin prevented the freeze inactivation. While the activity of the LDH solution frozen without additives was almost lost during a day of frozen storage, those frozen with either glutamate (0.2 M) or albumin (0.1%) added decreased less quickly. The residual activity after 1 day was 50% the initial prefreeze value for the former and 10% for the latter, respectively. Combined use of glutamate and albumin prevented the inactivation the best and maintained the initial activity almost completely over 6 weeks. The enzymes tested lost some part of their activity when their solutions were diluted by the media. This inactivation was prevented to a significant extent by the addition of sodium glutamate and/or albumin to the diluting media.     

Histochemical observations on the occurrence of glycolytic and pentose phosphate cycle enzymes in the hepatopancreas and their possible relation to eyestalk factor(s) in the crab Scylla serrata (Forskal).

Histochemical studies were carried out on some of the glycolytic enzymes viz. phosphorylase, aldose, alpha-glycerophosphate dehydrogenase (alpha-GPDH) and lactic dehydrogenase (LDH) and a key enzyme of the pentose phosphatase cycle, glucose-6-phosphate dehydrogenase (G-6-PDH), in the hepatopancreas of Scylla serrata (Forskal). 1. Weak activities of phosphorylase and aldolase and strong-activities of alpha-GPDH and LDH were noticed mainly in the brush border of the tubules and R-cell cytoplasm. A trace activity of G-6-PDH was noticed in the brush border. 2. Bilateral eyestalk removal results in inhibition of both phosphorylase and aldolase. However, enhanced activities of alpha-GPDH and LDH were noticeable 4 h after the operation. The G-6-PDH activity remained unaltered till 24 h. 3. Injection of eyestalk extract into both intact and destalked crabs activated all the enzymes.     

Glycolytic enzymes in the premolt field crab Paratelphusa hydrodromus (Milne-Edwards) (Crustacea)

The quantitative assay of hexokinase (HK), phosphorylase, phosphofructokinase (PFK), glucose 6-phosphate dehydrogenase (G-6-PDH), glycerol 3-phosphate dehydrogenase (G-3 PDH) and lactate dehydrogenase (LDH) revealed that coxal muscles compared to hepatopancreas contained higher activities of all the enzymes investigated. It appears that the coxal muscles of the premolt field crab has carbohydrate-based fuel economy. The hepatopancreas is a rich source of lipid and very poor source of glycogen. The activity of G-6-PDH is moderately high in the hepatopancreas. It seems that in this lipogenic tissue conversion of G-6-P to triose phosphate occurs predominately via pentose-phosphate pathway thus generating NADPH for lipogenesis. The relative G-3PDH ad LDH activities in hepatopancreas and coxal muscles led us to believe that the reconversion of NAD from NADH in hepatopancreas nd muscle flexor is effected by glycerol 3-phosphate shuttle, whereas in muscle extensor it is achieved by both G-3PDH and LDH activities.     

Influence of L-thyroxine upon enzymatic activity in the renal tubular epithelium of the rat under normal conditions and mercury-induced lesions. II. Histochemical studies of lactate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, unspecific esterase, and glucose-6-phosphate dehydrogenase.

Mercury-induced renal tubular lesions in the rat present histochemically with a decrease of succinate dehydrogenase (SDH), malate dehydrogenase (MDH), glucose-6-phosphate dehydrogenase (G-6-PD), and unspecific esterase (UE), but with an increase of lactate dehydrogenase (LDH), indicating a drop of energy supply as well as a switch from oxidative to glycolytic energy production. L-thyroxine has the same effect on SDH, G-6-PD, and LDH, but an inverse effect on MDH and UE, pointing to stimulation of gluconeogenesis. However, administration of L-thyroxine to animals which have been submitted to sublimate intoxication even further decreases the MDH and UE activity while raising or partly restoring the activity of LDH, SDH, and G-6-PD. This observation is interpreted as an attempt of the damaged epithelial cell, as the gluconeogenesis ceases, to gain relatively more energy supply for the benefit of the vitally indispensable tubular Na+ reabsorption.     

Activités de quelques enzymes associés à la conidiogenèse du Neurospora crassa

Summary Enzyme activities have been measured and compared at several stages of the development of Neurospora crassa i.e. from free conidia (inoculum) to conidiated mycelia grown on sucrose versus acetate (poor versus highly conidiogenous) media.Glucose-6-phosphate dehydrogenase (G-6-PDH) and NADP nucleotidase (NADPase) show inverse activity-time curves, both on sucrose and acetate media. G-6-PDH has its higher activity at the preconidiating stage while NADPase progressively increases to reach its maximal value in the mature conidia.Malate dehydrogenase (MDH) has a higher activity in extracts from acetate compared to sucrose cultures; in both conditions, maximal MDH activity corresponds with the initiation of conidiation. Malate synthetase (MS) has a delayed activity which is much higher in acetate extracts.Succinate dehydrogenase (SDH) is more active in sucrose than acetate extract with a sharp activity peak just preceding conidiation proper.Isozymes of G-6-PDH and MDH, as well as total soluble proteins from extracts of sucrose versus acetate cultures have been compared after their separation on polyacrylamide columns.     

砷对兰州鲇组织中代谢酶活性及RNA和蛋白质含量影响

采用毒性试验方法,研究了安全浓度（1.288 mg/L）条件下亚砷酸钠（NaAsO2）对兰州鲇（Silurus lanzhouensis）脑、鳃、肝脏、肌肉4种组织中6-磷酸葡萄糖脱氢酶（G-6-PDH）和乳酸脱氢酶（LDH）活性,以及RNA和蛋白质含量的影响。结果表明,染毒21d时,As（Ⅲ）可显著降低4种组织中G-6-PDH和LDH活性、RNA和蛋白质含量（P0.05）。撤毒后21d,除脑和肝组织中蛋白质含量未恢复到对照组水平（P0.05）,肝脏中G-6-PDH活性超过了对照组水平（P0.05）外,其余各组织中G-6-PDH和LDH活性、RNA和蛋白质含量均可恢复到对照组水平（P0.05）。以上结果表明,As（Ⅲ）对兰州鲇组织中代谢酶活性具有明显的抑制作用,可致组织细胞RNA损伤和可溶性蛋白质减少,但这种影响是可逆的,撤毒后一定时间内可恢复到正常水平。       

Effect of tuftsin on the activity of energy metabolism enzymes in peritoneal macrophages

Cytochemistry was used to measure the activity of succinate dehydrogenase (SOD), lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G-6-PDH) in rat peritoneal macrophages under the action of the endogenous immunostimulant tuftcin (tre-lys-pro-arg) during phagocytosis of latex particles and at rest. Tuftcin did not affect the activity of the study enzymes in non-phagocytic cells. Elevation of the peptide concentration to 0.25 micrograms/ml and higher in phagocytic macrophages activated G-6-PDH and lowered the activity of LDH. Tuftcin did not alter the activity of SOD in phagocytic macrophages.     

Aldrin toxicity on amphibian neuronal, hepatic and muscular tissue oxidative enzymes

Aldrin toxicity was studied in the brain, liver and muscle of Rana hexadactyla. It was observed that sublethal concentration of aldrin inhibited the activities of SDH, MDH and ICDH while it elevated the activities of LDH and G-6-PDH. The increase and the decrease was progressive with the exposure period. The changes were attributed to the induced toxic effects such as oxygen distress, energy crisis and microstructural changes.     

Delta 5-3 beta-hydroxysteroid dehydrogenase, succinate dehydrogenase and glucose-6-phosphate dehydrogenase in the bovine corpus luteum of estrous cycle: a quantitative histochemical study

Genital organs and blood were obtained from dairy cows at a local abattoir. 3 recently ovulated follicles and 20 corpora lutea of estrous cycle (CLC) were used for the quantitative enzyme histochemical demonstration of delta 5-3 beta-hydroxysteroid dehydrogenase (3 beta-OHSDH), succinate dehydrogenase (SDH) and glucose-6-phosphate dehydrogenase (G-6-PDH) activity, employing a computerized microscope photometer. Progesterone was determined in blood serum by radioimmunoassay. Luteal tissue was grouped into several stages of development according to micromorphological criteria. Activities per volume unit of 3 beta-OHSDH and SDH in large luteal cells (LLC), as well as in small luteal cells (SLC), and luteal tissue (LT), relative amounts of the 3 beta-OHSDH-positive tissue fraction (PLCC), and progesterone concentrations in blood serum exhibited a significant pattern corresponding to the morphological development of the endocrine gland. G-6-PDH showed an increase in activity per volume unit during tissue development lasting until the beginning of regressive changes, and as significant in LLC and LT. Activities per volume unit of 3 beta-OHSDH (p less than or equal to 0.001) and SDH (p less than or equal to 0.01) were higher in LLC than in SLC, indicating superior steroidogenic capacities, while G-6-PDH activity was distinctly higher in the latter (p less than or equal to 0.001). Almost all parameters tested were correlated positively. 3 beta-OHSDH and SDH exhibited a significantly positive correlation in LLC (p less than or equal to 0.01) and LT (p less than or equal to 0.001) during periods of measureable progesterone secretion. In SLC this correlation was nonsignificant (p greater than 0.05). G-6-PDH showed a relative poor correlation to 3 beta-OHSDH (LLC, p less than or equal to 0.05; LT, p less than or equal to 0.01) and SDH (LT, p less than or equal to 0.05). Enzyme activities in LLC as well as in SLC were generally positively correlated (p less than or equal to 0.001). All enzymes tested exhibited a significantly positive correlation with progesterone concentrations in blood serum. This was significant for SDH only during measurable progesterone secretion, and less marked for G-6-PDH.     

Methodological aspects of the histochemical localization and activity of some cerebellar dehydrogenases

Summary In a detailed study focused on the methodological problems in dehydrogenase histochemistry [e.g., fixation, diffusion of enzymes and of reduced inermediates, conversion of NADPH and NADP to NADH and NAD, respectively, penetration of tetrazolium salt and formazan substantivity, nothing dehydrogenase reaction, use of exogenous CoQ₁₀ and of flavoprotein substitute (PMS)], the distribution and activity of succinate dehydrogenase, NAD(P)H-tetrazolium reductase, glucose-6-phosphate dehydrogenase, lactate dehydrogenase (H and M types), and of l-glutamate dehydrogenase (E.C. 1.4.1.2 and E.C. 1.4.1.3) have been investigated in the rat cerebellum.It was evident from the study that reliable results could only be obtained if all the aforementioned factors had been considered. The image of actual concentration of SDH in the neuropil of the molecular layer could only be recorded by adding CoQ₁₀, while other structures exhibited greater balance between SDH and endogenous mitochondrial CoQ. Contrary to previous studies, a reversed localization of the activity of G-6-PDH and LDH was noticed. The elements of molecular and Purkinje layers were rich in G-6-PDH, while the granular layer was nearly depleted. The actual level of LDH could only be recorded if NADH-tetrazolium reductase was bypassed with PMS. The H and M types of LDH coexisted in the three cortical layers, the H type being prevalent and the M type attaining its highest level in synaptic glomeruli followed by the structures of the molecular layer and the Purkinje cells. High activity of GDH was noticed in Bergmann glia followed by synaptic glomeruli, while most other structures showed weak to moderate activity. The two GDH types coexisted in all structures showing activity, except for Bergmann cells, which only showed presence of the E.C. 1.4.1.3 type.Furthermore, Bergmann glia was exceptional by showing no activity of SDH and LDH, but strong activity of G-6-PDH and NADPH-tetrazolium reductase. The granular cells were exceptional by showing weak or no activity of all enzymes in question.     

Functional interrelations between isozymes of dehydrogenases in the intact and denervated rabbit muscles]

A correlation is shown to exist between malate dehydrogenase (MDH), lactate dehydrogenase (LDH) and glycerol-3-phosphate dehydrogenase (glycerol-3-PDH activity values, lactate/pyruvate and malate/oxaloacetate coefficients, MDH and LDH isozyme spectra and kinetic properties of LDH isozymes in soluble fractions of cytoplasm from intact rabbit m. soleus (red), m. gastrocnemius (mixed) and m. quadratus lumborum (white). In denervated soleus and gastrocnemius the cytoplasmic MDH/LDH, mitochondrial MDH/LDH, MDH mitochondrial/MDH cytoplasmic activity ratios, concentrations of substrates and isozyme spectra of MDH and LDH tend to equalize. The obtained results indicate the importance of isozyme composition and total activity ratios of the dehydrogenases for regulation of pyruvate and NADH metabolic pathways.     

国人睾丸、附睾和输精管的氧化还原酶的组织化学观察

本文收集了１９—３８岁国人正常男性新鲜睾丸、附睾和输精管１３例,进行了氧化还原酶组织化学染色、光镜定位及定性观察。结果表明：睾丸曲细精管和输出小管上皮的ＧＤＨ,ＮＡＤＨＤ,ＮＡＤＰＨＤ,ＳＤＨ,ＧＰＤＨ,ＩＣＤＨ,ＭＤＨ,ＬＤＨ和Ｇ－６－ＰＤＨ９种酶;睾丸间质细胞和附睾管上皮的ＮＡＤＨＤ,ＮＡＤＰＨＤ,ＳＤＨ,ＩＣＤＨ,ＭＤＨ,ＧＤＨ,ＬＤＨ和Ｇ－６－ＰＤＨ８种酶;输精管的ＮＡＤＨＤ,ＮＡＤＰＨＤ,ＩＣＤＨ和ＧＤＨ４种酶的酶活性呈强阳性或极强阳性。提示输出小管和头部附睾管含有的多种氧化还原酶对精子功能成熟有极重要作用。     

Activity of energy metabolism related enzymes in the myocardium and liver following administration of large doses of noradrenaline]

The activity of the glycolytic enzymes and of the glucose-6-phosphate dehydrogenase (G-6-PDH) were compared with the content of noradrenaline in rat myocardium and the liver after the intraperitoneal injection of high doses of noradrenaline. It was shown that 24 hours after int noradrenaline injection which caused exhaustion of endogenous catecholamine supply, the lactate content and the activities of lactic dehydrogenase were increased in the myocardium; the activity of hexokinase and G-6-PDH in rat myocardium and the liver were also increased, whereas the glucokinase activity was decreased. In these experiments alterations of the enzyme activities were shown to be similar to the alterations in the dystrophic tissues in which the catecholamine content was sharply decreased. The role of the sympathetic nervous system and its mediators in the mechanism of the enzyme regulation of the energy metabolism in the myocardium and the liver is discussed.     

Glucose-6-phosphate dehydrogenase plays a pivotal role in nitric oxide-involved defense against oxidative stress under salt stress in red kidney bean roots

The pivotal role of glucose-6-phosphate dehydrogenase (G-6-PDH)-mediated nitric oxide (NO) production in the tolerance to oxidative stress induced by 100 mM NaCl in red kidney bean (Phaseolus vulgaris) roots was investigated. The results show that the G-6-PDH activity was enhanced rapidly in the presence of NaCl and reached a maximum at 100 mM. Western blot analysis indicated that the increase of G-6-PDH activity in the red kidney bean roots under 100 mM NaCl was mainly due to the increased content of the G-6-PDH protein. NO production and nitrate reductase (NR) activity were also induced by 100 mM NaCl. The NO production was reduced by NaN(3) (an NR inhibitor), but not affected by N(omega)-nitro-L-arginine (L-NNA) (an NOS inhibitor). Application of 2.5 mM Na(3)PO(4), an inhibitor of G-6-PDH, blocked the increase of G-6-PDH and NR activity, as well as NO production in red kidney bean roots under 100 mM NaCl. The activities of antioxidant enzymes in red kidney bean roots increased in the presence of 100 mM NaCl or sodium nitroprusside (SNP), an NO donor. The increased activities of all antioxidant enzymes tested at 100 mM NaCl were completely inhibited by 2.5 mM Na(3)PO(4). Based on these results, we conclude that G-6-PDH plays a pivotal role in NR-dependent NO production, and in establishing tolerance of red kidney bean roots to salt stress.     

Glutathione system adaptation to acute stress in the heart of rats during different regimes of hypoxia training

The intensity of lipid peroxidation (LPO), reduced and oxidized glutathione (GSH and GSSG) contents, glutathione reductase, glutathione peroxidase, glutathione-S-transferase, glucose-6-phosphate dehydrogenase (G-6-PDH), and NADP-isocitrate dehydrogenase (NADP-IDH) activities were studied in the heart of male rats exposed to two modes of intermittent hypoxic training (IHT): I-breathing in normobaric chamber with 7% O2 gas mixture for 5 min with 15 min normoxic intervals 4 times daily during 3 weeks; II-breathing by 12% O2 gas mixture in the same manner). After adaptation to hypoxia, the rats were subjected to 6h-immobilization stress. It has been shown that stress action after IHT (regime I) caused the increase in LPO and the shift of GSH/GSSG to disulfides. A disbalance in antioxidative defense system was determined by the decrease in glutatione peroxidase, G-6-PDH activities, and GSH content. The support of glutathione reductase activity under stress in this group with simultaneous decrease of enzyme activity in the pentose phosphate pathway was realized through the participation of NADP-IDH. Hypoxic training in regime II induced LPO decrease in the heart tissue after stress. The increase in the heart GSH content, optimal balance of glutathione-related enzymes in this group evidences for the dependence of adaptation effects on the vigor of hypoxic exposition. Our results suggest the active participation of glutathione system in the formation of adaptation reactions under the extreme factor influences through the action on intracellular red/ox potential as well as effectiveness of antioxidant defense.     

Changes in fructosediphosphate aldolase and glucose-6-phosphate dehydrogenase activity after irradiation of animals with an absolute lethal dose of gamma rays

A single total-body exposure of rats to gamma-rays in an absolutely lethal dose caused significant changes in the activity of fructosodiphosphate aldolase (ALD) and glucose-6-phosphate dehydrogenase (G-6-PDH) in the brain, liver, myocardium and skeletal muscles. The activity of ALD was mainly inhibited and that of G-6-PDH increased. Thus, the initial step of glycolysis was significantly inhibited and the key reaction of the pentose phosphate pathway enhanced in the irradiated body.     

Changes in lipid peroxide levels and activity of reactive oxygen scavenging enzymes in skin, serum and liver following UVB irradiation in mice.

The effect of acute UVB on the generation of reactive oxygen species (ROS) in the skin and the induction of ROS scavenging enzymes in situ was examined. Lipid peroxide levels and the activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px) and D-glucose-6-phosphate dehydrogenase (G-6-P-D) were determined in the skin, serum, and liver of ICR mice subjected to 1400 mJ/cm2 of acute UVB irradiation. In irradiated skin, lipid peroxides were increased at 3 and 24 hr after irradiation, whereas the four ROS scavenging enzymes were generally decreased during the first 48 hr after irradiation. In the serum, lipid peroxides showed an increase at 3 hr, but enzyme activities remained negligible. In the liver, lipid peroxides showed similar behaviour to that in skin. GSH-Px activity in the liver was decreased during the first 24 hr, whereas G-6-P-D showed substantial fluctuation and SOD and catalase activities showed no change. These data are consistent with a model in which lipid peroxides generated in the UVB-irradiated lesions are transported to the liver and there metabolized by the scavenging enzymes induced in situ.     

The development of lactate and malate dehydrogenases in the C57BL-6 mouse kidney

The development of lactate dehydrogenase (LDH; EC 1.1.1.27) and malate dehydrogenase (MDH; EC 1.1.1.37) was measured in the kidney of male and female $\text{C57BL}\text{6}$ mice from ages prenatal 16 days to 80 days. Maximum reactions rates of the enzymes were measured in vitro by following the reduction of the nicotinamide-adenine dinucleotide spectrophotometrically.Analysis of variance showed no significant sex difference for LDH and MDH. There was a significant sex difference for the ratio LDH:MDH and a significant age difference for LDH, MDH, and the ratio LDH:MDH. In the male and female, LDH activity increased from prenatal 16 days to 30 days. Malate dehydrogenase activity reached adult values at 22 days in the male and at 30 days in the female. The ratio LDH:MDH in the male decreased from prenatal 16 days to 3 days, after which the ratio continued to decline to 20 days at a less rapid rate. This general pattern was also found in the female followed by a further decline in the ratio at 50 days.The development of LDH and MDH in the $\text{C57BL}\text{6}$ mouse is tissue specific and probably parallels the development of the tissue's function. In the case of the kidney, LDH and MDH development may reflect maturation of mitochondrial function and the kidney's ability to concentrate urine.     

Changes in ECG and enzyme activity in rat heart after myocardial infarction: effect of TPP and MnCl2

Heart infarction is one of the main causes of death in the human population. Assurance of a sufficient level of bioenergetic processes is very important for the heart after infarction. Mn²⁺ as well as thiamine pyrophosphate (TPP) are positive effectors of the pyruvate dehydrogenase complex (PDH) and the 2-oxoglutarate dehydrogenase complex (OGDH), both of which play a very important role in the Krebs cycle. Thus, we have established the effect of MnCl₂ (10mg/kg) and TPP (20mg/kg)-4 injections every 12 h-on the activity of PDH, OGDH, lactate dehydrogenase (LDH) and malate dehydrogenase (MDH). Additionally, we perform an analysis of ECG to affirm the changes in the heart electrophysiology of healthy rats after MnCl₂ and TPP treatment. We then analyzed changes in the activity of these enzymes after experimental myocardial infarction in rats. We observed a decrease of OGDH and MDH activity in rat hearts after infarction in comparison, with sham-operated rats. Treatment of healthy rats with MnCl₂ caused an increase of OGDH activity. Moreover both MnCl₂ and TPP caused an increase of PDH activity and a decrease of MDH activity (TPP revealed a stronger effect). We found no changes in LDH activity. Electrocardiography data showed a slight shortening of the QT interval and an enhanced heartbeat rate after treatment with MnCl₂. TPP caused only elongation of the QT interval. In conclusion, application of MnCl₂ enhanced the activity of some very important enzymes in the respiration process (PDH and OGDH). This effect, connected with enhanced heartbeat and a slightly shortened ventricle relaxation, may have potential application during the key period of convalescence following heart infarction.