Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.3.5.1 (succinate dehydrogenase)
8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Classification of muscle fiber types involves tedious comparisons of serial muscle tissue sections. Procedures that would incorporate pertinent histochemical properties into one simplified assay for the successful differentiation and determination of fiber types were evaluated using muscle samples from three different species (ovine, bovine and porcine). For ovine and porcine muscle tissue, the best staining procedure involved initial preincubation of the tissue section at 4.35 (for ovine) and 4.30 (for porcine) followed by incubating for succinate dehydrogenase (SDH) activity, then staining for myofibrillar adenosine triphosphatase (ATPase) activity after an acid preincubation and, finally, counterstaining with hematoxylin. For bovine muscle tissue, the procedure involves first incubating for SDH activity, after which the section is incubated at pH 4.15 and then stained for myofibrillar ATPase activity after an acid preincubation, with a concluding counterstaining using hematoxylin. These procedures permit successful differentiation and identification of three fiber types (beta R, alpha R and alpha W) from a single section of muscle tissue with approximately a 65% saving in time and materials. The results of histochemically typing muscle fibers in a single tissue section stained with these techniques were similar to those obtained with the traditional methods comparing serial sections.
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PMID:Simultaneous histochemical determination of three fiber types in single sections of ovine, bovine and porcine skeletal muscle. 336 12

Regions within frog semitendinosus muscle that are rich in tonic muscle cells were identified histochemically by myosin adenosine triphosphatase- and succinic dehydrogenase-staining procedures. Bundles of cells still attached to tendinous insertions were removed from those sites, prepared for electron microscopy and sectioned longitudinally through their myotendinous junctions. Tonic cells were identified by electron-microscopic criteria and their myotendinous junctions' morphology evaluated by morphometry. Although junctional components appear identical to those in twitch cells, the degree of membrane folding increases tonic junction area by a factor of 50.2 whereas twitch cells' junctional area is increased 22.2 times by folding relative to cells terminating as right circular cylinders. Calculations show that the tonic cell junction bears average loads of 3.4 X 10(3) N X m-2 during maximum force generation and that nearly all of the load is borne as shear stress at the junction. The junctions of twitch cells bear average loads of 1.6 X 10(4) N X m-2 during peak tension. The findings indicate that the magnitude of loading does not alone determine the degree of junctional membrane folding. Interpretation of the data in view of viscoelastic behavior of membranes indicates that duration of loading may be a functionally important correlate to degree of membrane folding at myotendinous junctions.
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PMID:Myotendinous junctions of tonic muscle cells: structure and loading. 348 10

The characteristic myopathic features revealed by histological observations included strong proliferation of connective and fatty tissue, perivascular infiltrations and necrosis of muscle fibers with phagocytosis to the lesser extent. In the myopathic muscle, as well as in giant fibers, histochemical techniques showed a reduction in succinate dehydrogenase and lactate dehydrogenase activity in type beta R (slow-twitch, oxidative) and alpha R (fast-twitch, oxidative and glycolytic). Magnesium-activated adenosine triphosphatase reaction ranged from diffuse to negative in beta R, alpha R and alpha W (fast-twitch, glycolytic) fiber types. Diffuse reaction for acid phosphatase and total loss of glycogen content were observed. The micrographs of the myopathic muscle indicated enlarged mitochondria with atrophy or complete destruction of cristae. Many myofibrils were hypercontracted. Giant fibers possessed mitochondria enlarged to an even greater extent and many of the myofibrils had loss of continuity, were narrow, depleted and were also hypercontracted. Significant differences between myopathic and normal groups were found in number of beta R fibers (lower in the myopathic group), number of alpha R fibers and percent of alpha R and alpha W fibers (higher in the myopathic group). Differences (P less than .01) existed between meat pH1 value in the myopathic group (mean value of 5.95) and the normal group (mean value of 6.29). Meat from the myopathic group of pigs also had a lower (P less than .01) pH24 value and reduced water-holding capacity (P less than .01) relative to the meat of the normal pigs. The lack of difference of fattening and slaughter traits between the groups suggested that the White Zlotnicka pigs is of particular value because it is possible to improve the production traits without increasing the incidence of these syndromes within the breed. Negative correlations (P less than .05) between number of giant fibers and percent of alpha W fibers, and between percent of giant fibers and percent of alpha W fibers indicate that alpha W fibers can undergo degeneration and be transformed into giant fibers. Therefore, it it suggested that giant fibers should be treated as muscular, pathological results of past stresses and not as an additional type of normal muscle cells.
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PMID:Histopathological observation of stress myopathy in M. longissimus in the pig and relationships with meat quality, fattening and slaughter traits. 362 2

In porcine areolar placental epithelia, the following enzymes were demonstrated by histochemical methods after 30, 58, 80, 100, and 110 d of pregnancy, respectively: beta-N-acetyl-hexosaminidase, beta-galactosidase, beta-glucuronidase, alpha-mannosidase, acid phosphatase, alkaline phosphatase, nonspecific esterases, cytochrome oxidase, 5-nucleotidase, leucine aminopeptidase, adenosine triphosphatase, diaphorases (NADH, NADPH), glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, succinate dehydrogenase, isocitrate dehydrogenase (NAD, NADP), beta-hydroxybutyrate dehydrogenase, glycero-3-phosphate dehydrogenase, NAD-glycero-3-phosphate dehydrogenase, glutamate dehydrogenase (NAD, NADP), lactate dehydrogenase. The results show that the enzyme activities remained almost unchanged during the period of investigation. Of the dehydrogenases, the diaphorases as well as succinate and lactate dehydrogenase demonstrated generally an intensive activity within the epithelia. The activity of the other dehydrogenases was only low. The activity of unspecific esterase was very intensive within the uterine epithelia but remarkably low within chorionic epithelia. Contrarily, the reaction of adenosine triphosphatase was more intensive within chorionic than uterine epithelia. All investigated glucosidases reacted distinctly positive within chorionic epithelia, but only beta-N-acetyl-hexosaminidase and beta-galactosidase in uterine epithelia. The high activity of acid phosphatase, especially within the chorionic epithelium, seems to be connected with uteroferrin, an iron-binding protein. The histochemical results are discussed in context with the function of the areolae in histiotrophic nutrition and iron transport.
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PMID:[Enzyme-histochemical studies of the pig placenta. II. Histotopics of enzymes in the areolar placenta epithelium]. 392 41

1. Assay conditions are described for the ATP-dependent, uncoupler-sensitive, energy-linked reduction of NAD(+) by succinate, dl-alpha-glycerophosphate or d-lactate in membranes from aerobically grown Escherichia coli. 2. The reaction may be demonstrated in electron-transport particles (ET particles) from cells grown in glycerol, but not in depleted particles washed in low-ionic-strength buffer, or in ET particles from cells grown in glucose. 3. The latter two classes of particles have low specific activities of ATPase (adenosine triphosphatase), succinate dehydrogenase, dl-alpha-glycerophosphate dehydrogenase and d-lactate dehydrogenase relative to undepleted ET particles from cells grown in glycerol. 4. Reconstitution of energy-linked NAD(+) reduction in particles from cells grown in glucose was done by: (a) addition of the high-speed supernatant fraction from sonicates of the same cells; (b) addition of a protein fraction, precipitated by (NH(4))(2)SO(4) from this supernatant, or (c) addition of an (NH(4))(2)SO(4)-precipitated fraction from the low-ionic-strength wash of particles from cells grown in glycerol. 5. The use of (NH(4))(2)SO(4)-precipitated fractions from ATPase- or succinate dehydrogenase-deficient mutants grown in glycerol in the above reconstitution indicated that failure to demonstrate the reaction in particles from cells grown in glucose was a result of inadequate activities of appropriate dehydrogenases, rather than of ATPase. 6. Energy-linked NAD(+) reduction could be demonstrated in particles from a ubiquinone-deficient mutant only after restoration of NADH oxidase activity by adding ubiquinone-1. 7. The measured rate of the energy-linked reaction in particles from a haem-deficient mutant, however, was not stimulated after the ATP- and haematin-dependent acquisition of functional cytochromes. 8. Results are interpreted as evidence of the ubiquinone-dependent, but cytochrome-independent, nature of the site I region of the respiratory chain in E. coli.
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PMID:Energy-linked reduction of nicotinamide--adenine dinucleotide in membranes derived from normal and various respiratory-deficient mutant strains of Escherichia coli K12. 415 32

1. The preparation of gram quantities of isolated epithelial-cell ;ghosts' from mucosal scrapings of rat small intestine is described. The method involves dispersing the tissue by gentle homogenization in 6% dextran in Krebs-Ringer phosphate, pH7.4, followed by filtration through nylon cloth and sedimentation by low-speed centrifuging. 2. The isolated epithelial-cell ;ghosts' contained all of the DNA, but only 52% of the protein and 53-57% of the RNA of the original homogenate. They contained most of the activity of the following enzymes found in the homogenate: aminopeptidase (71%); alkaline beta-glycerophosphatase (82%); invertase (92%); adenosine triphosphatase (93-116%); acid beta-glycerophosphatase (83%); nonspecific esterase (76%); succinate dehydrogenase (96%). Only small proportions of the total lactate-dehydrogenase (10%) and phosphoglucose-isomerase (2%) activities found in the homogenate were recovered in the isolated cell ;ghosts'. 3. The epithelial-cell ;ghost' preparation did not respire unless cofactors and substrates were added, and did not consume glucose or produce lactic acid from glucose. 4. The effect of varying the composition of the homogenization medium was studied. Concentrations of dextran (mol.wt. 15x10(4)) from 1 to 12%, solutions of dextrans (all at 6%) with mol.wt. varying between 3.6x10(4) and 2x10(6), and a solution of 8% polyethylene glycol (mol.wt. 4000) served equally well for the production of epithelial-cell ;ghosts'. Two of these solutions, however, 12% dextran (mol.wt.15x10(4)) and 6% dextran (mol.wt. 2x10(6)), were too viscous to allow the complete sedimentation of the cell ;ghosts' at low relative centrifugal forces. Omission of either Krebs-Ringer phosphate or dextran from the medium resulted in almost complete cell breakage during the homogenization. 5. The isolated cell ;ghosts' were used as a starting material for subcellular fractionation of rat intestinal mucosa by differential centrifugation. The distributions of protein and succinate-dehydrogenase activity among the fractions were compared with corresponding values in fractions isolated by differential centrifugation of mucosa homogenized in 0.3m-sucrose-5mm-EDTA, pH7.4. The method in which cell ;ghosts' were used as starting material gave a better separation and cleaner fractions than the method in which untreated mucosal scrapings were used.
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PMID:The isolation and properties of epithelial-cell "ghosts" from rat small intestine. 422 Sep 68

The virus of transmissible gastroenteritis produced sprue-like lesions in the small intestines of young pigs. These lesions were characterized by villous shortening, fusing and blunting in the jejunum and ileum. There was decreased height of the brush border and morphologic alteration of the villous epithelial cells from simple columnar to a variable cuboidal type. Accompanying these microscopic lesions were histochemical changes characterized by decreased staining intensity of acid phosphatase, alkaline phosphatase, adenosine triphosphatase, leucine aminopeptidase, succinic dehydrogenase and malic dehydrogenase in the affected intestinal mucosa. The clinical nature of transmissible gastroenteritis in the pig together with the histopathologic and histochemical changes may provide a useful experimental model for obtaining additional basic information on enteric disturbances.
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PMID:Experimental sprue-like small intestinal lesions in pigs. 422 30

1. The activity of 25 substituted 2-trifluoromethylbenzimidazoles in uncoupling oxidative phosphorylation by rat-liver mitochondria has been compared. 2. For halogen- or mixed-halogen- and alkyl-substituted analogues, uncoupling activity was proportional to the acidity of the imidazole -NH group. Tetrachloro-2-trifluoromethylbenzimidazole was the most active (50% uncoupling of oxidative phosphorylation at 7.9x10(-8)m, pK5.04). Nitro-substituted analogues were less active than predicted from pK considerations or from partition-coefficient measurements. 3. Introduction of an -NH(2) or -CO(2)H substitutent caused a loss of uncoupling activity, as did alkylation at position 1 of the imidazole ring. 4. Benzimidazoles active as uncouplers stimulated mitochondrial adenosine triphosphatase but not all stimulated the oxidation of succinate in the absence of a phosphate acceptor. 5. 4,5-Dichloro-2-trifluoromethylbenzimidazole inhibited the succinate-oxidase system at about the same concentration required for uncoupling (0.52mum for 50% inhibition of both activities) and the site of this inhibition appears to lie between succinate dehydrogenase and cytochrome b.
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PMID:Properties of substituted 2-trifluoromethylbenzimidazoles as uncouplers of oxidative phosphorylation. 429 94

In order to evaluate the possible role of sodium- and potassium-activated adenosine triphosphatase in the active transport of sodium by the renal tubules, we examined the effect of large changes in the tubular reabsorptive load of sodium on the Na-K-ATPase activity of rat kidney homogenates. Glomerular filtration and tubular reabsorption of sodium per gram of kidney tissue increased progressively after contralateral uninephrectomy. This was paralleled by an increase in Na-K-ATPase per milligram of protein in a microsomal fraction of kidney cortex. The importance of this change is underlined by the absence of simultaneous increases in other microsomal enzymes such as glucose-6-phosphatase and Mg(++)-dependent ATPase, or in succinic dehydrogenase or glutaminase. Similar increases in Na-K-ATPase were observed when the net tubular reabsorption of sodium was increased by feeding the animals a high-protein diet or after injection of methylprednisolone. On the other hand, Na-K-ATPase was lowered when tubular transport of sodium was reduced by bilateral adrenalectomy. The results of these experiments show that renal Na-K-ATPase changes in an adaptive way when renal reabsorption of sodium is chronically increased or diminished and support the hypothesis that this enzyme system is involved in the process by which sodium is actively transported across the renal tubule.
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PMID:The role of sodium-potassium-activated adenosine triphosphatase in the reabsorption of sodium by the kidney. 429 72

The activity of sodium-potassium-activated adenosine triphosphatase (Na-K-ATPase) is considerably higher in homogenates of outer medulla than in the cortex or papilla of the kidney. The enzyme has similar kinetic characteristics in both cortex and medulla, and binds ouabain in the same proportion. The discrepancy in enzymatic activity is not paralleled by similar change in the activity of adenyl cyclase, 5'nucleotidase, glucose-6-phosphatase, or succinic dehydrogenase. Na-K-ATPase is also higher in distal convoluted tubules (ventral slices) than in the proximal tubules (dorsal slices) of the kidney of Amphiuma. The high concentration of Na-K-ATPase in the red medulla of the kidney is probably related to the presence here of the thick ascending limb of the loop of Henle, and this has important implications with regard to the mechanism of sodium reabsorption by different portions of the nephron.
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PMID:The distribution of sodium-potassium--activated adenosine triphosphatase in medulla and cortex of the kidney. 432 13


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