Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.3.5.1 (succinate dehydrogenase)
 8,177 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Enzyme activities (units/g wet wt.) were determined in the caput and cauda epididymidis and in epididymal spermatozoa of the rat. 2. The activity of most enzymes in the cauda was between 50 and 100% of that in the caput, except that ATP citrate lyase was barely detectable in the cauda. 3. Spermatozoa, unlike epididymal tissue, contained sorbitol dehydrogenase but lacked ATP citrate lyase. NADP+-malate dehydrogenase, mitochondrial glycerol 3-phosphate dehydrogenase, succinate dehydrogenase, carnitine acetyltransferase and citrate synthase were 5 to 400 times as active in spermatozoa as in epididymal tissue. 4. 2-Oxoglutarate dehydrogenase was the least active member of the tricarboxylic acid cycle in all tissues and most closely matched the measured flux through the cycle. 5. The concentrations of hydroxyacyl-CoA dehydrogenase and carnitine palmitoyltransferase were equivalent to the more active enzymes of the tricarboxylic acid cycle, indicating the capacity for extensive lipid oxidation, and the presence of 3-hydroxybutyrate dehydrogenase suggests that these tissues can also oxidize ketone bodies. 6. Transfer of reducing equivalents from cytoplasm to mitochondrion is unlikely to occur by means of the glycerol phosphate cycle because mitochondrial glycerol 3-phosphate dehydrogenase is relatively inactive in epididymal tissue, whereas the cytoplasmic enzyme has little activity in spermatozoa, but transfer may be accomplished by the malate-aspartate shuttle. 7. Transfer of acetyl units from mitochondrion to cytoplasm could be effected by the pyruvate-malate cycle in the caput of androgen-maintained rats, but not in the other tissues because of the low activity of ATP citrate lyase. Acetyl unit transfer could take place via acetylcarnitine, mediated by carnitine acetyltransferase. 8. Castration resulted in a decrease in the concentration of nearly all enzymes, although subsequent administration of testosterone restored concentrations to values similar to those in animals maintained by endogenous androgen. The extent to which enzyme concentration was changed by an alteration in androgen status was highly variable, but was most marked in the case of pyruvate carboxylase.
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PMID:Activity and androgenic control of enzymes associated with the tricarboxylic acid cycle, lipid oxidation and mitochondrial shuttles in the epididymis and epididymal spermatozoa of the rat. 72 83

The myoepithelium of developing, lactating, and involuting mammary gland of the mouse exhibits a high alkaline phosphatase activity. The content of the alveoli and the apical plasma membrane of gland cells histochemically show enzyme activity before and after lactation but not during milk secretion. In the course of involution the alveoli shrink in size and the reaction of alkaline phosphatase becomes stronger in the gland tissue. In whole breast tissue the enzyme activity decreases, because in this time a great part of the alveoli are degraded and replaced by connective tissue and fat. As measured by a scanning microdensitometer the activity of some oxydoreductases (3-hydroxybutyrate dehydrogenase, lactate dehydrogenase, malate dehydrogenase, and succinate dehydrogenase) increase in proceeding development of the mammary gland and reach their highest level at the time of lactation. Already 12 h after the start of involution the oxydoreductases loose 30 to 50% of their activity and undergo a further reduction 3 to 4 days later. On the other side the activity of lysosomal enzymes increase during involution. beta-Glucuronidase and leucine aminopeptidase have their highest activity in the early stage of involution, whereas acid phosphatase predominate in the late period of gland degradation.
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PMID:[Microdensitometric measurement enzyme activities in the mammary gland of the mouse]. 83 21

Enzyme-histochemical studies were conducted on livers of mice chronically fed griseofulvin (GF) in order to produce Mallory bodies (MBs) in hepatocytes. The development of MBs is associated with derangement of the immunohistochemically detectable intermediate filament (IF) cytoskeleton of the cytokeratin (CK) type, although no strict correlation between appearance or involution of MBs and the cytoskeletal alterations exists. Since the function of the IF cytoskeleton and the relationship of its disturbance to cell injury is unknown, the aim of the present study was to correlate the activities of several key enzymes of cellular metabolic pathways with the disturbance of the cytoskeleton architecture. For that purpose enzyme-histochemistry in combination with immunohistochemical CK-IF stainings were performed on identical sections. In GF-intoxicated mouse livers the normal topography of enzyme activities was disturbed, but no strict colocalization of enzymatic and cytoskeletal changes was found. Glucose-6-phosphatase, a microsomal enzyme involved in glucose output and gluconeogenesis, showed elevated activity in MB-free hepatocytes with diminished immunostainable CK-IF cytoskeleton refuting the concept of a disability of those cells to export glucose. It could indeed indicate that those cells without MBs are in the state of recovery. However, these cells could also resemble "hyperactive foci". Glycogen was decreased in MB-containing hepatocytes with disturbed cytoskeleton, and this feature favours the assumption of cell degeneration. On the other hand, the mitochondrial marker enzymes, i.e. succinate dehydrogenase, cytochrome-c-oxidase and 3-hydroxybutyrate dehydrogenase, remained unchanged in altered hepatocytes. Alkaline phosphatase activity at the canalicular pole of GF-intoxicated hepatocytes was elevated, indicating cholestatic features associated with this disorder. However, since altered hepatocytes did not show impairment of oxido-reductase activities, a severe impairment of bile secretion as a consequence of cell damage is unlikely. Unchanged or even increased ATPase activity of altered hepatocytes also indicated their sustained metabolic abilities. The results presented provide indirect evidence that hepatocytes with disturbed IF cytoskeleton do not significantly differ from normal cells with respect to oxidative metabolism, fatty acid synthesis and gluconeogenesis. This suggests that alterations of the IF cytoskeleton associated with GF intoxication and MB formation have no significant adverse influence on the metabolic functions of liver cells, as far as can be assessed by evaluation by enzyme-histochemical staining of several key enzymes.
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PMID:Enzyme-histochemical studies of griseofulvin-intoxicated mouse livers. 165 25

In the present work the effects of corticosterone restitution were examined in female rats with chronic streptozotocin (SZ)-induced diabetes upon intact liver mitochondrial function and the activities of 3-hydroxybutyrate dehydrogenase (HBD), succinate dehydrogenase (SD) and cytochrome c oxidase (Cox) of the ruptured organelle. The liver mitochondrial function was analyzed by the respiration and the osmotic oscillatory behaviour. Respiration was measured by polarographic method and both the state 3 of active respiration (S3) and the respiratory control (RC) were determined using the following substrates: 3-hydroxybutyrate, succinate and malate-glutamate. The oscillatory behaviour was measured using as parameters the damping factors (DF) which are the ratios of amplitudes of two consecutive peaks or troughs of the spectrophotometrical tracings of this phenomenon. A group of control normal rats (N) and the following three groups of diabetic rats were studied: controls (D), adrenalectomized (D + ADX) and adrenalectomized with corticosterone restitution (D + ADX + C). The results of mitochondrial respiration showed that the mean values of S3 and RC decreased with the three substrates in the group D + ADX + C compared with D + ADX group (p < 0.001). This group demonstrated a significant increase of S3 and RC values of the respiration compared with the D group. The oscillatory behaviour of liver mitochondria of D + ADX + C group demonstrated a significant increase in the DF of peaks and troughs compared with D + ADX group. The values of DF of the latter group were not significantly different from the N group. The behaviour of the enzymes activities of ruptured liver mitochondria were different for each enzyme in the different groups of treated rats. Thus, in the D + ADX + C group the mean value of the activity of HBD significantly decreased, that of the Cox increased (p < 0.02) and that of SD did not show any variation compared with the corresponding values of the D + ADX group. Likewise, the mean value of HBD activity in this latter group was similar to that of the N group and that of Cox activity was lesser (p < 0.01) than that of the D group. The conclusion is drawn that corticosterone has significant additional diabetogenic effects upon biochemical functions of liver mitochondria in the SZ-induced diabetic state which could occur through the hormone cellular receptors.
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PMID:Effects of withdrawal of glucocorticoids on improving the function and enzymatic activities of liver mitochondria in female diabetic rats. 166 73

Heart mitochondria from chronically diabetic rats ('diabetic mitochondria'), in metabolic State 3, oxidized 3-hydroxybutyrate and acetoacetate at a relatively slow rate, as compared with mitochondria from normal rats ('normal mitochondria'). No significant differences were observed, however, with pyruvate or L-glutamate plus L-malate as substrates. Diabetic mitochondria also showed decreased 3-hydroxybutyrate dehydrogenase and succinyl-CoA: 3-oxoacid CoA-transferase activities, but cytochrome content and NADH-dehydrogenase, succinate dehydrogenase, cytochrome oxidase and acetoacetyl-CoA thiolase activities proved normal. The decrease of 3-hydroxybutyrate dehydrogenase activity was observed in diabetic mitochondria subjected to different disruption procedures, namely freeze-thawing, sonication or hypoosmotic treatment, between pH 7.5 and 8.5, at temperatures in the range 6-36 degrees C, and in the presence of L-cysteine. Determination of the kinetic parameters of the enzyme reaction in diabetic mitochondria revealed diminution of maximal velocity (Vmax) as its outstanding feature. The decrease in 3-hydroxybutyrate dehydrogenase in diabetic mitochondria was a slow-developing effect, which reached full expression 2-3 months after the onset of diabetes; 1 week after onset, no significant difference between enzyme activity in diabetic and normal mitochondria could be established. Insulin administration to chronically diabetic rats for 2 weeks resulted in limited recovery of enzyme activity. G.l.c. analysis of fatty acid composition and measurement of diphenylhexatriene fluorescence anisotropy failed to reveal significant differences between diabetic and normal mitochondria. The Arrhenius-plot characteristics for 3-hydroxybutyrate dehydrogenase in membranes of diabetic and normal mitochondria were similar. It is assumed that the variation of the assayed enzymes in diabetic mitochondria results from a slow adaptation to the metabolic conditions resulting from diabetes, rather than to insulin deficiency itself.
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PMID:Decreased rate of ketone-body oxidation and decreased activity of D-3-hydroxybutyrate dehydrogenase and succinyl-CoA:3-oxo-acid CoA-transferase in heart mitochondria of diabetic rats. 354 9

To differentiate the effect of muscle contractile activity from that of motor nerve on oxidative processes in type I muscle, oxidative processes were studied in muscle after immobilization and after denervation. The two processes led to similar atrophy of muscle weight and of the mean diameter of muscle fibers. Disuse of soleus muscle (type I) did not affect rates of oxidation of 14C-labeled substrates although these were reduced by disuse of the vastus lateralis (type II). Disuse of the soleus did not affect activities of several mitochondrial enzymes assayed by histochemical or biochemical methods. However, denervation of the soleus did lead to a fall in metabolic rates and enzyme activities. The activity of 3-hydroxybutyrate dehydrogenase fell more than did the activities of succinic dehydrogenase, lipoamide dehydrogenase, or cytochrome-c oxidase in both homogenates and in mitochondrial fractions. These results suggest nerve may regulate mitochondrial enzymes in type I muscle. The mechanism appears to be different from that which regulates oxidative processes in type II muscle.
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PMID:Effects of denervation and simple disuse on rates of oxidation and on activities of four mitochondrial enzymes in type I muscle. 625