Metabolic differentiation of homologous leg muscles of two aquatic birds at the level of enzymatic organization

The quantitative determination of succinic dehydrogenase (SDH), hexokinase (HK), phosphorylase, phosphofructokinase (PFK), glycerol-3-phosphate dehydrogenase (G-3-PDH) and lactate dehydrogenase (LDH) was carried out in the homologous leg muscles of two aquatic Birds. It appears that the leg muscle fibres of the coot, a surface swimmer are more oxidative in nature and appear to utilize glucose as source of energy. The leg muscles of the dabchick, a diving Bird, on the other hand, seem to depend on glycogen as source of energy. The relative activity levels of HK, phosphorylase and PFK support the accepted r?le of glycogen as primary substrate of carbohydrate catabolism in the leg muscles. The ratio of G-3-PDH/LDH in the leg muscles revealed that glycerol 3-phosphate cycle appears to be insufficient to account for the major part of NADH oxidation. However, the LDH activity is quite high in all the muscles. These results led us to believe that glycerol 3-phosphate cycle may function during rest, when the rate of glycolysis will be low.     

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.     

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。       

Enzymatic activity in crude oil contaminated rats

The activity of enzymes found in the plasma, malate dehydrogenase (MDH) and lactate dehydrogenase (LDH), and enzymes from erythrocytes, glucose-6-phosphate dehydrogenase (G-6-PDH) and catalase, was studied in rats contaminated by crude oil. Crude oil (tube fed) contamination caused a significant increase in MDH and LDH activity 96 hr after contamination while a decrease in activity was noted in 6-6-PDH and catalase. An additional contamination (1 week after the first contamination), measured 96 hr after contamination, caused a relative decrease in MDH and LDH activity while there was a contrasting relative increase in G-6-PDH and catalase activity. After a recovery period of 3 weeks the only significant change was an increase in catalase activity.     

人参皂甙Rb1,Rg1,Re和Rh1对细胞脱氢酶活性的影响

应用显微分光光度术,定量地分析了人参皂甙Rb_1、Rg_1、Re、Rh_1对人胚肺成纤维细胞(2BS)和HeLa细胞脱氢酶活性的影响。结果表明,4种单体皂甙增加了高代龄2BS细胞内乳酸脱氢酶(LDH),琥珀酸脱氢酶(SDH),葡萄糖-6-磷酸脱氢酶(G-6-PDH)和丙酮酸脱氢酶(PVO)的活性,降低了HeLa细胞内这几种酶的活性。     

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).     

Metabolic background for establishment of the subpopulation structure in early ontogenesis in the Atlantic salmon (the case of energy of carbohydrate metabolism)

The activity of some enzymes involved in energy and carbohydrate metabolism was studied in Atlantic salmon embryos at the eyed egg stage and in salmon fingerlings (0+) from two trophic–ecological groups: the Varzuga River bed and two tributaries, the Pyatka and Sobachii rivers (Kola Peninsula). It has been demonstrated that heterogeneity of embryos was most evident in the case of cytochrome c oxidase (CO), malate dehydrogenase (MDH), glycerol-1-phosphate dehydrogenase (G1PDH), and glucose-6-phosphate dehydrogenase (G6PDH), while the lowest level of heterogeneity was observed for lactate dehydrogenase (LDH) and aldolase. A positive correlation was revealed between the activities of CO, LDH, MDH, and G1PDH. It was noted that G6PDH showed a negative correlation with almost all enzymes under study. It was found that salmon juveniles inhabiting the tributaries were characterized by high LDH, aldolase, and G1PDH activity and lower activity of G6PDH compared to the juveniles inhabiting the main river bed. Notably, the differences in the activity of the enzymes involved in aerobic metabolism between the two groups of fingerlings under analysis were observed only in the autumn.     

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.     

Die Histotopik einiger Oxydoreduktasen im Hoden von Hund und Katze

Zusammenfassung Im Hoden von Hund und Katze werden folgende Enzyme histochemisch nachgewiesen: NADH-Tetrazoliumreduktase (NADH-T-Red), NADPH-Tetrazoliumreduktase (NADPH-T-Red), Cytochromoxydase (Cyt-Ox), Lactat-Dehydrogenase (LDH), Aldolase (ALD), Alkohol-Dehydrogenase (ADH), Glycerin-1-phosphat-Dehydrogenase (GDH), Glucose-6-phosphat-Dehydrogenase (G-6-PDH), Succinat-Dehydrogenase (SDH), NAD-spezifische Isocitrat-Dehydrogenase (NAD-ICDH). Die starke Fermentaktivität der G-6-PDH und der LDH in den Leydig-Zellen beider Spezies, der relativ hohe Gehalt an histochemisch nachweisbarer ADH in den Zwischenzellen der Katze sowie eine deutliche Reaktion auf GDH in den Sertoli-Zellen der Katze werden diskutiert.

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Summary In the testes of dog and cat the distribution pattern of NADH-tetrazolium reductase, NADPH-tetrazolium reductase, cytochrome oxydase, lactate dehydrogenase, aldolase, alcohol dehydrogenase, -glycerophosphate dehydrogenase, glucose-6-phosphate dehydrogenase, succinate dehydrogenase and NAD specific isocitrate dehydrogenase was studied by histochemical means. The strong reaction of G-6-PDH and LDH in the Leydig cells of both species, the relatively high amount of ADH in the interstitial cells of the cat testis and the principal site of -GPDH in the Sertoli cells of the cat are discussed.

     

Starvation-induced impairment of metabolism in a freshwater catfish

Starvation induced changes in citrate synthase (CS), glucose-6-phosphate dehydrogenase (G6-PDH), lactate dehydrogenase (LDH), DNA, RNA, RNA/DNA ratio and protein were studied in the freshwater catfish Clarias batrachus. Starvation gradually decreased the activity of CS, G6-PDH and LDH in brain, liver and skeletal muscle of the freshwater catfish. The maximum reduction in these enzyme activities upto 35-45% was observed after 35 days of fasting. This shows substantial decline in aerobic and biosynthetic capacity during starvation period. DNA, RNA, RNA/DNA ratio and protein contents were also reduced from 40-67% which reflects reduction in an overall capacity of the protein synthesis. Starvation-induced macromolecular changes indicate impairment of metabolism in fish.     

Isolation of enzymes from mixed reversed micelles of surface-active agents

The catalytic activities of lysozyme, horseradish peroxidase (HP), catalase, glucose-6-phosphate dehydrogenase (G6PDH) and lactate dehydrogenase (LDH) were studied in aqueous solutions and after isolation of the enzymes from mixed reversed micelles of Aerosol OT and Triton X-45 by organic solvents (acetone, ethanol, isopropanol), by acetone-water mixtures, as well as by aqueous solutions containing urea, glycerol, polyethylene glycol 6000 and ammonium sulphate. The isolation conditions were found for catalase with retaining all the activity and for HP and lysozyme with retaining 72 and 84% of the catalytic activity, respectively. The G6PDH isolation from micelles by aqueous solutions of urea (6%) and glycerol (10%) resulted in retaining only 43% of the enzyme activity and led to almost complete inactivation of LDH. Stability of the enzymes after their entrapment in micelles and isolation from those is compared with thermostability of the same enzymes in aqueous solutions.     

The correlation between fish growth and several biochemical characteristics with reference to the steelhead <Emphasis Type="Italic">Parasalmo mykiss</Emphasis> Walb.

Correlation analysis demonstrated a statistically significant correlation of linear-weight characteristics of the steelhead rainbow trout (cultivated steelhead form) with an RNA/DNA ratio and the expression level of the gene encoding cytochrome c oxidase (CCO) in two-year-old individuals (1+) as well as the expression level of the gene encoding the myosin heavy chain (MyHC) and activities of the enzymes CCO and lactate dehydrogenase (LDH) in muscles and 1-glycerophosphate dehydrogenase (1-GPDH) and glucose-6-phosphate dehydrogenase (G6PDH) in the liver of two- and three-year-old individuals (1+ and 2+). With age, the correlation of 1-GPDH and G6PDH activities in the rainbow trout liver with the fish body weight increased, whereas their correlations with the body length reduced. The age- and sex-related distinctions in the MyHC gene expression and activities of the white muscle enzyme LDH and the liver enzymes 2-GPDH and G6PDH were detected in rainbow trout of both age cohorts.     

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.     

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.     

Meldola Blue: A new electron carrier for the histochemical demonstration of dehydrogenases (SDH,LDH, G-6-PDH)

Summary A new electron carrier, Meldola Blue (8-dimethylamino-2,3-benzophenoxazine; Boehringer Mannheim GmbH, Deutsche Patentschrift P 1959410) was tested for its usefulness in the histochemical demonstration of dehydrogenase activity in adrenal cortex, liver, heart muscle of guinea pig and human oviduct and compared with PMS.For demonstrating SDH activity Meldola Blue (MB) is as efficient as PMS. A decisive advantage of MB as compared with PMS is its low sensitivity to light exposure, facilitating direct visualisation of histochemical reaction processes.Generally, a high diffusion rate of reduced electron carriers (PMS and MB) from the section into the incubation medium (PVA) leads to a loss of reduction equivalents, particularly in the demonstration of NAD- or NADP-dependent dehydrogenases (LDH, G-6-PDH) with lower TNBT concentrations. However, no inhibition of SDH-, LDH- and G-6-PDH activities was observed with incubation media containing the tested concentrations of PMS and MB.     

Differential effects of thyroxine on metabolic enzymes and other macromolecules in a freshwater teleost

The effects of thyroxine (T(4)) on citrate synthase (CS), glucose 6-phosphate dehydrogenase (G6-PDH), lactate dehydrogenase (LDH), DNA, RNA, and protein of various tissues were studied to elucidate the hormonal control of metabolism in a freshwater catfish, Clarias batrachus. T(4) did not produce any significant effect on DNA content of the fish. The CS, RNA, and protein contents of brain, liver, and skeletal muscle of the fish exposed to thiourea for 28 days decreased approximately 50-58% as compared to their levels in control individuals. Injection of T(4) to thiourea-exposed fish produced about three-fold increases in CS, RNA, and protein. These macromolecular inductions by T(4) were blocked by actinomycin D or cycloheximide. This suggests T(4)-induced de novo synthesis of macromolecules and stimulation of aerobic capacity. However, the activities of G6-PDH and LDH of brain, liver, and skeletal muscle of the fish exposed to thiourea increased two times that of the activities in control individuals. Administration of T(4) to thiourea-exposed fish reduced LDH and G6-PDH activities by about 64-74%, which reflects T(4)-dependent inhibition in anaerobic power and selective anabolic activities of the HMP pathway. These differential effects of T(4) on some metabolic enzymes and other important macromolecules may be to meet the other T(4)-induced responses in the freshwater catfish.     

Stimulatory Effect of Insulin and Epidermal Growth Factor on Activity of Protein Kinase A, Glucose-6-Phosphate Dehydrogenase, and Glycogen Synthase in Skeletal Muscles of Chick Embryos and Chickens

Insulin is able to produce two types of regulatory effects on muscles—metabolic and growth stimulating. Study of the effect of insulin and epidermal growth factor (EGF) on activity of cAMP-dependent protein kinase (PKA), glucose-6-phosphate dehydrogenase (G-6PDH), a starting enzyme of pentosephosphate pathway (PPP), and glycogen synthase (GS), a key enzyme of the glycogen synthesis, has shown that both types of the insulin effects do not arise simultaneously in the course of embryogenesis. The growth-stimulating effect mediated by adenylyl cyclase—cAMP is revealed since the 10th embryonal day. It was established for the first time that insulin could participate in growth stimulation by activating PKA in vivo and in vitro in muscles of the 10–14-day old embryos and the 8–10-day old chickens. The stimulating effect of insulin on G-6PDH activity is revealed since the same embryonal period and gradually increases. Insulin in vivo and in vitro simulates the glycogen synthase activity by increasing its conversion from non-active to active (GS-I) form only in the 15-day old embryos and in chickens. The stimulating effects of insulin and EGF on both G-6PDH activity (in embryos and chickens) and GS (in chickens) was shown to blocked by selective inhibitors of tyrosine kinases, thyrphostin 47 and genestein, in the dose-dependent manner, which indicates involvement of receptor of the tyrosine kinase type in these effects. The complex of the established facts permits concluding that insulin at early embryonal stages stimulates in the chicken muscles the PKA and G-6PDH activities involved in action of this hormone on growth, which is especially pronounced at the stage of myoblast proliferation. Meanwhile, the metabolic insulin effect (stimulation of the glycogen synthase system) appears in the second half of embryonal period and coincides in time with the period of muscle cell differentiation and active muscle contractures.     

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.     

Glycerol Phosphate Dehydrogenase, Glucose-6-Phosphate Dehydrogenase, and Lactate Dehydrogenase: Activities in Oligodendrocytes, Neurons, Astrocytes, and Myelin Isolated from Developing Rat Brains

Abstract: Glycerol phosphate dehydrogenase (GPDH), glucose-6-phosphate dehydrogenase (G6PDH), and lactate dehydrogenase (LDH) activities were determined in Oligodendrocytes, neurons, and astrocytes isolated from the brains of developing rats. The activity of each enzyme was significantly lower in both neurons and astrocytes than in Oligodendrocytes. The GPDH activity in Oligodendrocytes increased more than 4-fold during development, and at 120 days cells of this type had 1.4-fold the specific activity of forebrain homogenates. The G6PDH activities in Oligodendrocytes from 10-day-old rats were 1.4-fold the activities in the forebrain homogenates. The activities of this enzyme in Oligodendrocytes were progressively lower at later ages, such that at 120 days the cells had 0.8 times the specific activities of homogenates. The Oligodendrocytes had 0.6 times the homogenate activities of LDH at 10 days, and this ratio had decreased to 0.2 by 120 days. These enzymes were also measured in myelin isolated from 20-, 60-, and 120-day-old rats. By 120 days the specific activities of G6PDH and LDH in myelin were <8% of the respective activities in homogenates. The GPDH activity in myelin was, however, at least 20% the specific activity in the homogenates, even in the oldest animals. It is proposed that LDH could be used as a marker for oligodendroglial cytoplasm in subfractions of myelin and in myelin-related membrane vesicles.     

The biochemical and morphological changes in the myocardium of patients with an acute surgical vascular pathology (based on data from early autopsies)]

Biochemical and morphological disorders of glucose 6-phosphate dehydrogenase (G-6-PDH) were studied in the myocardium of 9 patients who had died from different vascular surgical diseases. The inhibition of G-6-PDH activity most prominent in lung artery thromboembolism was shown biochemically. Histological and histoenzymological findings demonstrate low G-6-PDH activity in different myocardial regions and solitary defects of cardiomyocytes. The data obtained evidence significant sensibility of the myocardium in surgical patients to different influences.