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)

The influence of prolonged nutritional deprivation on the succinate dehydrogenase (SDH) activity and cross-sectional areas of individual fibers in the rat diaphragm and deep portion of the medial gastrocnemius (MGr) muscles was determined. Fatigue resistance of the diaphragm was measured by means of an in vitro nerve-muscle strip preparation. Fiber SDH activity and cross-sectional area were quantified by means of an image processing system. Diaphragm fatigue resistance was significantly improved in the nutritionally deprived (ND) group. In both muscles, nutritional deprivation resulted in a significant decrease in fiber cross-sectional area (both type I and II), type II fibers showing greater atrophy. The SDH activities of type I and II fibers in the diaphragm were not affected by nutritional deprivation. This contrasted with a significant decrease in the SDH activity of both type I and II fibers in the MGr of ND animals. An assessment of the interrelationships between fiber atrophy and fiber SDH activity revealed a greater effect of malnutrition on those diaphragm type II fibers that had the lowest relative SDH activities and the largest cross-sectional areas. By comparison, the effect of malnutrition on type I and II fibers in the MGr was nonselective with regard to fiber SDH activity. We conclude that the enhanced diaphragm fatigue resistance in the ND animals does not result from an increase in the oxidative capacity of muscle fibers and is best explained by the pattern of diaphragm muscle fiber atrophy.
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PMID:Effects of undernutrition on diaphragm fiber size, SDH activity, and fatigue resistance. 274 85

The muscle fiber types and sizes in the M. stapedius (middle ear muscle) of the domestic chicken, Gallus gallus were determined histochemically on the basis of their reactions to myofibrillar adenosine triphosphatase (mATPase), succinic dehydrogenase and NADH diaphorase. Only type II fibers were identified at pH 9.4 and 4.2. At pH 4.6 three levels of activity were seen: high, intermediate and low. With the staining techniques three subtypes of fibers for oxidative enzymes, Types II1 (highly glycolytic), II12 (intermediately glycolytic and lipolytic) and II123 (highly lipolytic) were identified. Fiber diameter was also measured for the different fiber types. The average fiber diameter was around 20 micron for each fiber type. Although similar in size, the fiber types were markedly different in their histochemical properties. These findings plus those of earlier physiological studies suggest that the M. stapedius of G. gallus is a fast twitch, muscle with fibers of similar diameter showing mainly fatigue resistance characteristics.
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PMID:A histochemical characterization of muscle fiber types in the avian M. stapedius. 288 51

The influence of variations in muscle fibre composition on isometric endurance capacity was measured in 23 young healthy untrained male volunteers. After determination of the maximum voluntary force of contraction (MVC), subjects sustained to fatigue contractions at forces of 80%, 50% and 20% of MVC with a 5-min rest between each. A needle biopsy was obtained from m. vastus lateralis and used for histochemical determination of fibre composition based on myosin ATP-ase activity, and fibre are a based on succinate dehydrogenase (SDH) activity. Endurance times were 21 +/- 9 s (mean +/- SD) at 80% of MVC, 56 +/- 17 s at 50% of MVC and 203 +/- 89 s at 20% of MVC. A wide range of muscle fibre compositions was observed with Type I fibres accounting for 48.0 +/- 10.5% of the total, corresponding to 45.0 +/- 11.5% of the total muscle area. Muscle fibre composition, whether expressed as the proportions of the different fibre types present, or as the fraction of total muscle cross-sectional area occupied by each fibre type was not correlated with isometric endurance capacity at any of the three forces studied. Endurance time was also unrelated to MVC. In contrast to the results of previous studies where trained subjects were used, or where different muscle groups were compared, these results suggest that isometric endurance is not influenced by muscle fibre composition.
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PMID:The relationship between muscle myosin ATP-ase activity and isometric endurance in untrained male subjects. 293 54

The succinate dehydrogenase (SDH) activity and cross-sectional area of individual muscle fibers in the cat diaphragm were quantified using a computerized image-processing system. The population distributions of fiber-SDH activities and cross-sectional areas showed considerable range within each diaphragm. Despite an overlap in the distribution of SDH activities between fast-twitch (i.e., those staining darkly for myosin ATPase) and slow-twitch (i.e., those staining lightly for myosin ATPase) fibers, differences between the two populations of fibers were observed. Fast-twitch fibers generally had lower SDH activities and greater cross-sectional areas than slow-twitch fibers. However, the range of SDH activities and cross-sectional areas of fast-twitch fibers was much greater than in slow-twitch fibers. The population distributions of SDH activities and cross-sectional areas of both fast- and slow-twitch fibers were unimodal. The unimodal distribution of SDH activities in fast-twitch fibers suggested that these fibers could not be clearly subdivided into two groups based on differences in their oxidative capacity (i.e., high- and low-oxidative fibers). These results were discussed in the context of the classification of fast-twitch glycolytic and fast-twitch oxidative-glycolytic fibers using qualitative histochemistry. In addition, the functional significance of the unimodal distribution of oxidative capacities in fast-twitch fibers was discussed in relation to the distribution of fatigue properties in fast-twitch motor units. A significant negative correlation between cross-sectional area and SDH activity in both fast- and slow-twitch fibers was also observed. The importance of this negative correlation in relationship to the diffusion of energy substrates for oxidative metabolism was discussed.
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PMID:SDH activity and cross-sectional area of muscle fibers in cat diaphragm. 293 51

The effects of 28 days of hindlimb suspension (HS) and HS plus 10 daily forceful lengthening contractions on rat soleus muscle fibers were studied. Compared with age-matched controls (CON), soleus wet weights of suspended rats were significantly decreased (approximately 49%). In HS rats, the light adenosinetriphosphatase (ATPase) fibers (staining lightly for myosin ATPase, pH = 8.8) atrophied more than the dark ATPase fibers (staining darkly for myosin ATPase, pH = 8.8). Single-fiber alpha-glycerophosphate dehydrogenase (GPD) and succinate dehydrogenase (SDH) activities and the proportion of dark ATPase fibers were higher in HS than CON rats. Daily forceful lengthening contractions did not prevent the suspension-induced changes. These results considered in conjunction with a collaborative study on the mechanical properties of HS rats (Roy et al., accompanying paper) suggest a shift in the contractile potential of the muscle following HS without a deficit in SDH, a metabolic property commonly associated with resistance to fatigue. The results support the view that soleus muscle fibers can change from a slow-twitch oxidative to a fast-twitch oxidative-glycolytic profile, but rarely to a fast-twitch glycolytic one, and that SDH and GPD activity per volume of tissue can be maintained or increased even when there are severe losses of contractile proteins.
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PMID:Size and metabolic properties of single muscle fibers in rat soleus after hindlimb suspension. 295 34

Most of the previous studies on the effects of iron deficiency on skeletal muscle respiratory capacity and work performance have been investigated in severe or moderate iron-deficiency anemia. We report here that even in mild iron deficiency where the hemoglobin concentration was 10 g/dl and the iron stores in livers and spleen were not completely depleted, a marked reduction in succinate dehydrogenase was observed in skeletal muscles but not in heart. Similarly, cytochrome oxidase activities were reduced. Although no significant change in glycerophosphate dehydrogenase was detected in the iron-deficient rats, exposure to cold in this group greatly reduced this enzyme activity. As cold acclimatization accelerates marrow erythropoiesis (20) which in turn, demands more iron, it seems that in the iron-insufficient state, this iron demand for marrow activity may persist at the expense of the tissue iron pool, resulting in a marked reduction in glycerophosphate dehydrogenase activities. Since succinate dehydrogenase plays a significant role in the impairment of mitochondrial function and early fatigue of iron-deficient muscle (11), the present study shows that even in mild iron deficiency, some loss of muscle functions could result as succinate dehydrogenase activities were greatly reduced.
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PMID:Biochemical effects of mild iron deficiency and cold acclimatization on rat skeletal muscle. 300 73

The contractile properties, morphology, and the distribution of striated muscle fiber types of the external and sphincter (EAS) were determined using axial force measurements, fiber size cross-sectional area measurements, and histochemistry. Electrical stimulation of motor axons in pudendal nerve at supramaximal intensities (10 V, 0.05 ms duration) elicited twitch contractions of EAS. The time to peak force after a single pulse ranged from 37 to 42 ms. The time for relaxation to half-maximal twitch force ranged from 20 to 29 ms. Repetitive stimulation of motor axons (0.1-3.0 Hz) produced potentiation and fatigue of single twitch contractile force, suggesting that the EAS of the cat is comprised predominantly of fast-twitch muscle fibers. Confirmation of skeletal muscle fiber types was determined by histochemistry. Frozen serial cross sections of EAS were incubated to demonstrate succinic dehydrogenase (SDH) and myosin adenosine triphosphatase after alkaline preincubation (pH 10.4). Based on these reactions, muscle fibers were classified as fast glycolytic (FG) (high ATPase, low SDH), fast oxidative-glycolytic (FOG) (high ATPase, high SDH), and slow oxidative (SO) (low ATPase, high SDH). The mean percentage +/- SE of each histochemical type was the following: FG, 73.5 +/- 3.9; FOG, 22.8 +/- 3.7; and SO, 3.7 +/- 0.6. These results indicate that the predominant fiber type for the EAS is FG. The EAS of the cat is considered a nominally fast-twitch muscle.
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PMID:Physiological, morphological, and histochemical properties of cat external anal sphincter. 320 71

The contractile properties of single motor units of rat plantaris were measured in situ 7 days following muscle partial denervation, achieved by section of radicular nerve L4. Partially denervated muscles weighed less, generated weaker twitch and tetanic forces, and contained denervated fibers, as evidenced by indirect/direct stimulation force ratios less than 1. Fast motor units (over 90% of unit pool) showed elevated twitch and tetanic responses (222% and 171% of controls, respectively) and elevated twitch-to-tetanic force ratios. Although partial denervation did not alter the mean fatiguability of fast motor units, fewer proportions of units remained in the extreme categories of fatigue resistance, with a clustering of units in the intermediate ranges. Slow units, while showing elevated twitch and tetanic responses, did not change in fatiguability. Glycogen depletion of the fibers of two fast motor units in partially denervated muscles revealed the presence of fibers varying in size, and in staining intensities for succinate dehydrogenase and ATPase, within the same motor unit, as a result of motoneurone sprouting.
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PMID:Force and fatiguability of sprouting motor units in partially denervated rat plantaris. 360 4

1. Long-term electrical stimulation was given to the peroneal nerve of deafferented hindlimbs in hemispinalized adult cats. The amount of stimulation covered 0.5-5.5% of total time per day, different in different animals. For some aspects of the present study, use was also made of cats subjected to "tonic" patterns of chronic stimulation (typically covering 50% of total time; 10, 16). 2. In a terminal acute experiment under general anesthesia, performed after 4 or 8 wk of long-term stimulation, one of the treated peroneal muscles (m. peroneus longus, PerL) was used for measurements of the resistance to contractile fatigue. The fatigue test consisted of 0.33-s bursts of motor-nerve stimulation at 40 Hz, repeated once a second for 4 min (6, 7). During this fatigue test, the evoked compound spikes of the muscle were recorded by electromyographic (EMG) techniques. Following the physiological procedures, PerL was removed for further histochemical analysis. In transverse sections, measurements of optical density were made in central regions of single fibers after staining for the activity of an oxidative enzyme, succinate dehydrogenase (core SDH). 3. Findings from chronically stimulated PerL muscles were compared with three kinds of control PerL muscles: 1) those contralateral to the stimulated ones, 2) those from the operated side of animals that had been deafferented and hemispinalized but not subjected to chronic stimulation, and 3) those from untreated normal animals. 4. Stimulation patterns covering both greater than or equal to 50% and 5-5.5% of daily time gave a marked improvement of fatigue resistance. Pulse rate seemed of little importance for these effects. The pattern covering only 0.5% of total daily time caused no increase of contractile endurance beyond that of normal muscles. 5. During the fatigue test of a control muscle (see above), the amplitude of the compound EMG spikes typically showed a marked decline. This "EMG depression" was effectively counteracted by all the present patterns of chronic stimulation, including the 0.5% pattern. 6. Fibers of chronically stimulated muscles became more similar to each other with respect to their density of core SDH staining. However, among muscles treated during 0.5-5.5% of total daily time, the degree and pattern of change in core SDH staining was not related to the amount and pattern of chronic stimulation or to the resulting degree of contractile endurance.
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PMID:Effects of physiological amounts of high- and low-rate chronic stimulation on fast-twitch muscle of the cat hindlimb. II. Endurance-related properties. 365 85

Fatigue indices and succinic dehydrogenase (SDH) activities were determined in the extensor digitorum longus (EDL) and soleus muscles of the hind limb and the extensor carpi radialis longus of the forelimb in control and dystrophic mice aged 4 to 26 weeks. A good correlation was found between SDH activities and fatigue indices in muscles from normal mice. In the dystrophic (dy2J) mice, however, this correlation was not present. The EDL muscles from 26-week-old dy2J mice showed a much higher resistance to fatigue than age-matched controls but this was not accompanied by a significant change in SDH. The increased fatigue resistance in dy2J EDL appeared between 8 and 12 weeks of age and was temporally correlated with the onset of fused bursts of spontaneous activity in the hind limb muscles. Nevertheless, there was no conclusive evidence for a link among this spontaneous activity, oxidative enzyme capacity, and fatigue resistance.
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PMID:Fatiguability and oxidative capacity of forelimb and hind limb muscles of dystrophic mice. 396 20


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