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)

A quantitative study has been made on the enzymic, chemical and ultrastructural changes that occur in the parotid glands of rabbits as a result of Isoprenaline-induced secretion. Emphasis has been placed on correlating changes in organelle and membrane content which are evident 2 hr after Isoprenaline administration and which have been measured stereologically with the levels of appropriate enzymic or chemical markers, taking into account the contribution made by both the acinar and duct tissue. Lower protein, alpha-amylase and beta-glycerophosphatase levels correlated with reductions in zymogen granule and lysosome volume with whilst plasmalemmal and Golgi membrane areas and their marker enzyme concentrations remained unchanged. However, declines in alkaline phosphatase and succinate dehydrogenase activity (illustrated histochemically), and p-nitrophenyl phosphatase activity at pH 4-5 in the presence of tartrate occurred without any detectable decrease in membrane area. Conversely, an increase in rough endoplasmic reticulum area was measured stereologically but no increases in chemical markers were detected. The extent of correlation of the data is discussed in the context of the mechanism of secretion and the action of Isoprenaline.
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PMID:Correlative morphological and biochemical study of the effects of isoprenaline on the organelle and membrane content of the rabbit parotid gland. 18 59

The microstructure of two type of muscles was studied in a selection experiment conducted with Dutch Large White pigs (boars and gilts) selected for either low backfat thickness (L-line) or fast growth (F-line). Second- and fourth-generation pigs were used to determine effects of selection on fiber type composition, fiber area, and capillary density in the longissimus lumborum (LL) and biceps femoris (BF) muscles. Immediately after slaughter samples were taken from the LL and BF muscles. The latter was divided into an inside (BFi) and outside (BFo) portion, which refer to the red and white portions of the biceps femoris. Serial sections were stained for ATPase (pH 4.60), succinate dehydrogenase (SDH), and alpha-amylase-periodic acid shiff (PAS) to determine fiber type and capillary density. The LL and BFo muscles had predominantly type IIBw fibers, whereas the BFi muscle had a 2 to 4 times higher amount of type I fibers. In most muscles there were more type I and fewer type IIBw fibers in F- than in L-line pigs (P < .05), except in the LL muscle of second-generation pigs and in the red part of the BF muscle of fourth-generation pigs. In both selection lines lower type I and higher type IIBw percentages were found in muscles from gilts than in those from boars (P < .05). Capillary density and fiber area of L- and F-lines showed minor differences, which could be explained by differences in weight and age of the pigs of both lines. The results suggest that selection for low backfat thickness in pig breeding compared with increased growth rate resulted in fewer oxidative and more glycolytic muscle fibers. The magnitude of the effect depended on muscle type and duration of the selection period.
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PMID:The effects of selection of pigs on growth rate vs leanness on histochemical characteristics of different muscles. 1083 78

In plants, differentiation of subdomains of the endoplasmic reticulum (ER) dedicated to protein export, the ER export sites (ERES), is influenced by the type of export-competent membrane cargo to be delivered to the Golgi. This raises a fundamental biological question: is the formation of transport intermediates at the ER for trafficking to the Golgi always regulated in the same manner? To test this, we followed the distribution and activity of two plant Sar1 isoforms. Sar1 is the small GTPase that regulates assembly of COPII (coat protein complex II) on carriers that transport secretory cargo from ER to Golgi. We show that, in contrast to a tobacco Sar1 isoform, the two Arabidopsis Sar1 GTPases were localised at ERES, independently of co-expression of Golgi-destined membrane cargo in tobacco cells. Although both isoforms labelled ERES, one was found to partition with the membrane fraction to a greater extent. The different distribution of fluorescent fusions of the two isoforms was influenced by the nature of an amino acid residue at the C-terminus of the protein, suggesting that the requirements for membrane association of the two GTPases are not equal. Furthermore, functional analyses based on the secretion of the bulk flow marker alpha-amylase indicated that over-expression of GTP-restricted mutants of the two isoforms caused different levels of ER export inhibition. These novel results indicate a functional heterogeneity among plant Sar1 isoforms.
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PMID:Plant Sar1 isoforms with near-identical protein sequences exhibit different localisations and effects on secretion. 1832 4

Hypoxia is one of the most frequently occurring stressors confronted by industrial cultures of sea cucumber and can cause large economic losses and resource degradation. However, its responsive mechanisms are still lacking. In this paper, the physiological responses of Apostichopus japonicus to oxygen deficiency was illustrated, including induced oxidative response and immune defense and changed digestive enzymes activities. Significantly increased activities of alpha-amylase (AMS), acid phosphatase (ACP), lactate dehydrogenase, catalase, peroxidase, succinate dehydrogenase and higher content of malondialdehyde, and decreased activities of lipase and trypsin (TRY) were observed after hypoxia exposure (dissolved oxygen [DO] 2 mg/L). Expressions of key genes showed that AMS, peptidase, ACP, alkaline phosphatase, lysozyme, heat shock protein 70 and glutathione peroxidase were increased and TRY was decreased under hypoxia. With the decline of the DO level, the decreased tendency of oxygen consumption rates was different in varied weight groups. Moreover, respiratory trees were observed degraded under long-term hypoxia stress, thus leading a negative effect of respiration. These results could help to develop a better understanding of the responsive mechanism of sea cucumber under hypoxia stress and provide a theoretical basis for the prevention of hypoxia risk.
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PMID:Impact of hypoxia stress on the physiological responses of sea cucumber Apostichopus japonicus: respiration, digestion, immunity and oxidative damage. 2971 35