Succinate dehydrogenase activity in the developing molar of the hairless mouse Mus musculus

Synopsis Succinate dehydrogenase activity in the odontogenic tissues of the hairless mouse (hr/hr) has been studied from the initiation of the dental lamina through apposition. Enzyme activities were designated as negative, slight, moderate and strong as a function of intensity of the reaction product. Enzyme levels in the odontogenic tissues increased with advancing tooth morphogenesis. Greatest activity was observed in the ameloblastic layer which peaked on the fourth to sixth postnatal days. This cell layer displayed higher enzyme activity than the ectomesenchymally-derived odontoblasts. Succinate dehydrogenase activity appeared to be related to the degree of differentiation and functional competence on the odontogenic tissues of the hairless mouse.     

Enzymatic Activity in Mitochondria from Orobanche

Mitochondria from Orobanche were analysed for the activities of aconitate hydratase, isocitrate dehydrogenase, succinate dehydro-genase, fumarate hydratase, malate dehydrogenase, NADH oxidase, substrate-cytochrome c oxidoreductases, glutamate dehydrogenase, aminotransferases, ATPase and “malic” enzyme. The specific activities of isocitrate dehydrogenase, NADH oxidase, substrate-cytochrome c oxidoreductases and glutamate dehydrogenase in the mitochondria) fraction from parasite tissue compared favourably with those reported for most of the mitochondria from growing and storage tissues. Succinate dehydrogenase, fumarate hydratase and aspartate aminotransferase were of intermediate activity, while aconitate hydratase and malate dehydrogenase had rather low activity, and “malic” enzyme had very low activity in comparison with other preparations. The relevance of these findings in relation to mitochondrial metabolism in the parasite is discussed. No evidence was obtained to suggest any basic abnormality in the biochemical properties of the mitochondria from Orobanche centua which may be correlated with its obligatorily parasitic existence.     

Succinate dehydrogenase activity in the developing molar of the Mongolian gerbilMeriones unguiculatus

Synopsis The distribution of succinate dehydrogenase in the odontogenic tissues in the Mongolian gerbil, ranging in age from 18 days prenatal to 8 days postnatal, was studied. Activity levels were designated negative, trace, slight, moderate, strong and very strong, dependent upon visual observations. The results indicated increased levels of activity as the tissue layers differentiated from the lamina stage through early apposition. The cell layer displaying the most succinate dehydrogenase activity was the ameloblastic layer while the stratum intermedium layer was the, next most active cell layer. Succinate dehydrogenase activity appeared to be related to the degree of differentiation and functional competency of the odontogenic tissues in the Mongolian gerbil.     

The action of the Notch locus in Drosophila melanogaster

Summary It is shown that the Notch⁸ deficiency in Drosophila melanogaster affects a number of enzyme activities localized in the mitochondria, such as NADH oxidase (activity of the complete respiratory chain), NADH dehydrogenase (the first step in the respiratory chain before transfer to ubiquinone), Succinate dehydrogenase and -Glycerophosphate dehydrogenase. The experiments reported here do not exclude the possibility of involvement of other genes in the deficiency. The effect of duplications of the Notch locus on NADH oxidase and NADH dehydrogenase suggest that this locus determines the enzyme activities.The dosage effects of the Notch locus on activity suggest that this locus contains the structural genes for these enzymes.     

Tissue effects of iron deficiency in the rat

Measurements of succinate dehydrogenase and mitochondrial glycerol-3-phosphate dehydrogenase activities, iron, cytochrome c and myoglobin, were made on various hind-leg muscles, fast-twitch red and white muscle and heart and liver of male Wistar rats fed an iron-deficient diet on weaning. Rats fed the same diet and given 20 mg iron intraperitoneally as iron-dextran (Imferon) served as controls. For iron-repletion studies anemic rats (hemoglobin less than 7 g/dl) were given a single injection of 10 mg iron (Imferon) and the time course of change in the above parameters was followed up to 22 days after injection. The iron concentration of most iron-deficient muscles dropped to approx. 35% of control, the heart to 60% and liver to 13%. On repletion, the iron concentration of all tissues increase significantly by 4 days. While the levels of cytochrome c and myoglobin approximated the iron levels in muscle, they did not change significantly in the heart. Succinate dehydrogenase activity dropped profoundly in muscle, to 10-30% of control; on repletion, the activity increased significantly. Mitochondrial glycerol-3-phosphate dehydrogenase activity showed only small changes in iron-deficient tissues.     

Succinate dehydrogenase and fumarate reductase activity in Aspiculuris tetraptera and Ascaris suum and the effect of the anthelmintics cambendazole,thiabendazole, and levamisole

Comley John C. W. and Wright Spdenis J. 1981. Succinate dehydrogenase and fumarate reductase activity in Aspiculuris tetraptera and Ascaris suum and the effect of the anthelmintics cambendazole, thiabendazole, and levamisole. International Journal for Parasitology11: 79–84. Succinate dehydrogenase and fumarate reductase activities from a particulate fraction of A. tetraptera and a soluble extract of A. suum have been determined using spectrophotometric methods. Fumarate reductase activity in A. suum could only be detected anaerobically. Succinate dehydrogenase activity from A. suum was partially characterized and shown to exist in several multimolecular forms (isoenzymes). The in vitro effect of the anthelmintics cambendazole, thiabendazole and levamisole on succinate dehydrogenase and fumarate reductase activity from the above nematodes are described. Significant inhibition of fumarate reductase activity of both nematodes was only achieved using 5 mM levamisole and 1 mM thiabendazole. After in vivo anthelmintic treatment of A. tetraptera only thiabendazole significantly inhibited fumarate reductase. It is suggested that the succinate dehydro-ogenase-fumarate reductase complex in these nematodes is unlikely to be the primary site chemotherapeutic attack for any of the anthelmintics tested.     

Studies on the cell cycle of Myxobacter AL-1

The properties of seven enzymes were studied in extracts from Myxobacter AL-1. The enzymes were isocitrate dehydrogenase (E.C. 1.1.1.42), succinate dehydrogenase (E.C. 1.3.99.1), alkaline phosphatase (E.C. 3.1.3.1), -glucosidase (E.C. 3.2.1.20), -glucosidase (E.C. 3.2.1.21), -galactosidase (E.C. 3.2.1.23), and N-acetyl-glucosaminidase (E.C. 3.2.1.30). Four of these enzymes: isocitrate dehydrogenase, -glucosidase, -glucosidase, and -galactosidase are cytosolic enzymes. Succinate dehydrogenase was found to be located on the cytoplasmic membrane system, whereas alkaline phosphatase and N-acetyl-glucosaminidase were considered as enzymes which bind the outer membranes resp. the cell wall. During the cell cycle, all enzymes have a pattern of discontinuous activity increase. Succinate dehydrogenase and isocitrate dehydrogenase exhibit a stepwise increase of activity, whereas the other enzymes follow the pattern of a peak enzyme.     

Enhancement of tumor cell susceptibility to lymphokine-activated killer cells by treatment with the streptococcal preparation OK432

We investigated whether tumor cell lysis by LAK cells was augmented by treatment with OK432in vitro. NK and LAK activity against K562 cells was not enhanced by their treatment with OK432. In contrast, the susceptibility of OK432-treated Daudi and KATO-III cells to lysis by LAK cells was enhanced. Succinate dehydrogenase activity and RNA synthesis were impaired in Daudi and KATO-III cells by treatment with OK432, and moreover the expression of HLA Class I antigen and ₂-microglobulin was inhibited in OK432-treated KATO-III cells. Thus, it is suggested that the enhancement of the susceptibility of OK432-treated tumor cells with regard to succinate dehydrogenase activity, RNA synthesis, and HLA Class I antigen expression.     

Subcellular Distribution of Aspartate Transaminase,Alanine Amino Transferase,Glutamate Dehydrogenases,and Lactate Dehydrogenase in Tetrahymena*

SYNOPSIS. Mitochondria and peroxisomes were isolated from homogenates of Tetrahymena pyriformis by sedimentation through a sucrose gradient. Succinate dehydrogenase was used as a mitochondrial marker; catalase and isocitrate lyase were used to mark the peroxisomal fraction. Lactate dehydrogenase, glutamate dehydrogenase, and alanine aminotransferase were found only in the mitochondrial fraction. Aspartate transaminase was found in both mitochondrial and peroxisomal fractions.     

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.     

Effect of succinate on mitochondrial lipid peroxidation. 2. The protective effect of succinate against functional and structural changes induced by lipid peroxidation

The damaging effects of ADP/Fe/NADPH-induced lipid peroxidation were studied on the enzymes and membranes of rat liver mitochondria. Succinate, an inhibitor of mitochondrial lipid peroxidation, prevented or delayed most of the damage caused by the peroxidation on different mitochondrial structures and functions. There were marked abnormalities on the electrophoretic pattern of mitochondrial proteins during the course of lipid peroxidation. The disappearance of particular polypeptide bands and the accumulation of high-molecular-weight aggregates could be observed. Succinate was found to delay these effects. As a consequence of lipid peroxidation the succinate oxidase activity of mitochondria was decreased. The succinate dehydrogenase enzyme and the component(s) of the respiratory chain were inactivated. Succinate prevented the inactivation of succinate dehydrogenase but did not protect the other components of terminal oxidation chain. From the matrix enzymes the glutamate dehydrogenase retained its full activity but the NADP-linked isocitrate dehydrogenase was inactivated. The mitochondrial membranes became permeable to large protein molecules. Succinate prevented the inactivation of isocitrate dehydrogenase and delayed the release of protein molecules from mitochondria.     

Hexose metabolism in pancreatic islets: Succinate dehydrogenase activity in islet homogenates

Succinate dehydrogenase activity was measured in rat pancreatic islet homogenates incubated in the presence of [1,4-¹⁴C]succinate, the reaction velocity being judged through the generation of ¹⁴CO₂ in the auxiliary reactions catalysed by pig heart fumarase and chicken liver NADP-malate dehydrogenase. In the presence of 1·0 mM succinate, the reaction velocity averaged 5·53 ± 0·44 pmol min^?1 μg^?1 islet protein. The K_m for succinate was close to 0·4 mM and the enzymic activity was restricted to mitochondria. These kinetic results indicate that, under the present experimental conditions, the activity of succinate dehydrogenase does not vastly exceed that of either NAD-isocitrate dehydrogenase or the 2-ketoglutarate dehydrogenase complex, at least when the latter enzymes are activated by ADP and/or Ca²⁺. Nevertheless, the activity of succinate dehydrogenase is sufficient to account for the increase in O₂ uptake evoked in intact islets by the monomethyl ester of succinic acid. It could become a rate-limiting step of the Krebs cycle in models of B-cell dysfunction.     

Receptivity of various wheat cultivars to infection by VA-mycorrhizal fungi as influenced by inoculum potential and the relation of VAM-effectiveness to succinic dehydrogenase activity of the mycelium in the roots

Wheat cultivars grown in pots in a greenhouse were inoculated either once or twice with the vesicular-arbuscular mycorrhizal fungus (VAMF) Glomus mosseae. If inoculum was only added to the soil once (before planting) the cultivars showed differences in subsequent VAM development. If additional inoculum was added ten days after planting, VAM development was much increased and cultivars which remained without VAM after only one inoculum application now became mycorrhizal.Succinate dehydrogenase (SDH) activity decreased throughout the experiment, but this decrease was less rapid in mycelium in twice-inoculated plants.No close relationship between SDH-activity and plant growth (VAM effectiveness) was found.     

Effect of acute hypoxia on the enzymes involved in the metabolic and nervous functioning of rat brain.

Rats were exposed to a simulated altitude of 25,000 ft for 4 h in a decompression chamber, and the activity of some tissue enzymes estimated. Succinate dehydrogenase activity was significantly decreased and cholinesterase activity significantly elevated in the brain homogenates of the hypoxic rats, succinic dehydrogenase activity was significantly increased. There was no change in the activity of Mg+2-ATPase and Na+-K+-ATPase in the microsomal fractions of liver or brain homogenates of the hypoxic animals.     

A correlation of the intensity of the gas discharge luminescence of the skin and the activity of succinate dehydrogenase in blood lymphocytes in different states of the body

The integral area of gas discharge luminescence of the hand finger skin and the activity of succinate dehydrogenase in lymphocytes in blood smears from patients with food allergia and attendant hypertension has been measured. Succinate dehydrogenase in these patients was hyperactivated or inhibited as compared with healthy persons. At more substantial deviations of activity, a more clearly pronounced hypertension was observed. The area of luminescence of the skin in some patients was near the upper boundary of norm or was beyond its limits. A high degree of correlation (r = 0.85) between the two parameters has been revealed. At moderate and high succinate dehydrogenase activity, the parameters of gas-discharge visualization decreased; the inhibition of succinate dehydrogenase activity enhances, the gas-discharge visualization increases. This probably indicates the contribution to the irradiation from hand fingers of the superoxide formed in the respiratory chain of mitochondria in the region of coenzyme Q upon its incomplete reduction caused by the inhibition of succinate dehydrogenase.     

OZONE DAMAGE TO PONDEROSA PINE: A HISTOLOGICAL AND HISTOCHEMICAL APPRAISAL

Histological and histochemical changes occurred in current-year needles of sensitive clonal selections of Pinus ponderosa Laws under natural summer growing conditions in the San Bernardino National Forest near Los Angeles, California due to fumigations with 0.45 ppm ozone for 12 hr/day. Within five days after the start of fumigation, chloroplasts and carbohydrate stain accumulated in the peripheral portions of mesophyll cells. Concurrently, the homogenous distribution of proteins and nucleic acids was disrupted. Succinate dehydrogenase was localized mostly in guard cells, resin duct epithelial cells, albuminous cells, and differentiating vascular tissues within unfumigated and fumigated leaves. Acid phosphatase activity increased within mesophyll cells during ozone exposure, but there was no association of acid phosphatase or ozone injury with stomata. Wall destruction occurred in mesophyll cells after appreciable intracellular damage. These histological and histochemical changes occurred within 5–7 days, but visual symptoms were not evident until 2–3 weeks after fumigation. It is thus possible to assay ozone damage very soon after exposure if no other external agents cause similar results.     

Enzyme activities in red and white muscles of guinea-pigs and rabbits indigenous to high altitude.

The activities of several enzymes functioning in different areas of fuel catabolism were measured under standardized conditions, using crude homogenates of sartorius and ventricular muscle from outbred guinea-pigs and rabbits indigenous to high or low altitude. The activities of sartorius and myocardium were found to reflect the metabolic patterns known to be associated with white and red muscle. Both species had right ventricular hypertrophy at high altitude. The enzyme activities in the high altitude guinea-pig were not significantly different from those in the sea level animals. In the high altitude rabbit, compared with the low altitude rabbit, the activities of glyceraldehyde-3-phosphate deydrogenase and phosphofructokinase were greater in both the sartorius and myocardium. In addition, mitochondrial glycerol-3-phosphate dehydrogenase activity was greater in the sartorius at high altitude, while aspartate aminotransferase and beta-hydroxyacylcoenzyme A dehydrogenase activities were greater in the myocardium at high altitude. Succinate dehydrogenase activity was comparable at the two altitudes for both tissues. There was a greater proportion of skeletal muscle type lactate dehydrogenase in the high altitude rabbit myocardium but no difference was found with the guinea-pig.     

Succinate-mediated catabolite repression of enzymes of glucose metabolism in root-nodule bacteria

Enzymes of the Embden-Meyerhof-Parnas and Entner-Doudoroff pathways were detected in strains ofRhizobium andBradyrhizobium cultured on glucose. The enzymes, except glyceraldehyde-3-phosphate dehydrogenase, were present only in trace amounts in succinategrown cells. The enzymes of the pentose phosphate pathway, being absent inBradyrhizobium, were detected only in glucose-grown cells ofRhizobium. The presence of the glucose-catabolic enzymes in cells only during growth on glucose suggests that they are inducible in nature. Succinate repressed the glucose catabolic enzymes, and the repression appeared to be similar to catabolite repression. Exogenous addition of cAMP caused no change in the activity of these enzymes, demonstrating that the repression was unlikely to be mediated via cAMP.     

Metabolic differences inBacillus stearothermophilus grown at 55°C and 37°C

Summary Bacillus stearothermophilus was adapted to grow at 55°C and 37°C in a complex medium with almost equivalent yields in cell mass. In both temperature ranges the maximum specific growth rates (μ_max) were identical. Cellular extracts of this bacterium showed remarkable differences in the activity levels of several enzymes, depending on the respective growth temperature. High activities of glyceraldehyde-3-phosphate dehydrogenase and alcohol dehydrogenase were observed in bacteria from thermophilic cultures (55°C) and the respiratory quotient exceeded 1.0. Under anaerobic conditions at 55°C μ_max was the same as in aerobic cultures. No alcohol dehydrogenase was detected in cells from mesophilic cultures (37°C), however, and the level of glyceraldehyde-3-phosphate dehydrogenase was also extremely low under mesophilic conditions. Succinate dehydrogenase and isocitrate dehydrogenase activity appeared to be higher in bacteria grown at 37°C; the resspiratory quotient was always lower than 1.0. At 37°C, acetoin formation was observed regularly, a fermentation product which was never detected in 55°C-cultures. Under anaerobic conditions at 37°C a very low growth rate was found. When adapted to grow at 37°C or 55°C,B. stearothermophilus is apparently able to use different catabolic systems.     

A quantitative histochemical study of lactate dehydrogenase and succinate dehydrogenase activities in the membrana granulosa of the ovulatory follicle of the rat

Using a microdensitometer, lactate dehydrogenase and succinate dehydrogenase activities were measured in the membrana granulosa of the rat ovulatory follicle. Ovaries were removed on each day of the oestrous cycle; oestrus, dioestrus-1, dioestrus-2, and proestrus; and enzyme activities measured in the membrana granulosa as a whole and in four regions within it: peripheral (PR), antral (AR), cumulus oophorus (CO) and corona radiata (CR). Throughout the cycle, lactate dehydrogenase activity was greatest in PR. On oestrus, lactate dehydrogenase activity was progressively less in AR, CO and CR. On dioestrus-1, activity was identical in AR and CO and less in CR. On dioestrus-2, activity was greater in AR than in CO or CR. By proestrus, activity was equal in AR, CO and CR. In the membrana granulosa as a whole, and in each region, lactate dehydrogenase activity declined as ovulation approached. In contrast, succinate dehydrogenase activity in the membrana granulosa as a whole and in PR was constant throughout the cycle. Activity fluctuated in the other regions. Succinate dehydrogenase activity on oestrus was greatest in PR, less in AR and CO and least in CR. On the remaining days, succinate dehydrogenase activity was greatest in PR and less but equal in the remainder of the membrana granulosa.