Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.6.4.1 (myosin ATPase)
 1,140 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. Cross sections from the middle of the gluteus medius were removed from 10 adult horses and used to evaluate changes in histochemically determined muscle fiber type and biochemically determined metabolic enzyme activities as a function of sample depth. 2. Muscle fiber types determined using histochemical methods for myosin ATPase (pH 9.4) and succinic dehydrogenase (SDH) activity indicated percent fast-twitch glycolytic (FG) muscle fibers decreased and slow-twitch oxidative (SO) fibers increased as a function of increasing sampling depth. 3. Percent histochemically determined fast-twitch oxidative glycolytic (FOG) fibers decreased slightly only in the deepest region of the gluteus medius. 4. Citrate synthase (CS) enzymatic activity, used as a marker for mitochondrial oxidative potential, increased 2.5-fold in activity per g of muscle protein from 1 to 8 cm sampling depth. 5. 3-hydroxyacyl-CoA dehydrogenase (HAD) enzymatic activity, used as a marker for lipid oxidation potential, increased 3-fold in activity per g of muscle protein when the depth increased from 1 to 8 cm. 6. Phosphorylase (PS) enzymatic activity, used as a marker for potential glycogen utilization, decreased 50% in activity per g of muscle protein when going from 1 to 8 cm. 7. Lactate dehydrogenase (LDH) enzymatic activity, used as a marker for anaerobic glycolytic potential, decreased about 50% in activity as the sampling depth increased from 1 to 8 cm. 8. In summary, the superficial portion of the equine gluteus medius was found to be more glycolytic and less aerobic in its metabolic profile than deeper regions. The muscle became progressively more aerobic and less glycolytic with increasing sampling depth.
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PMID:Changes in the metabolic profile of the equine gluteus medius as a function of sampling depth. 290 49

Masseter muscles from normal and dystrophic mice were investigated with the electron microscope and by the use of histochemical techniques for myosin ATPase and succinic dehydrogenase activity. The observations show that the muscle fibers are severely affected in the masseter of the dystrophic mouse.
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PMID:Electron microscopic and histochemical studies on dystrophic masseter muscle. 293 34

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 activity of succinic dehydrogenase, myosin ATPase, as well as lactic dehydrogenase (LDG) spectrum and cross-section area of different type of muscle fibers have been studied for 3 weeks after denervation (control) and after denervation and intraperitoneal injection of 10(-6) M FeCl3. Intraperitoneal injection of FeCl3 prevented the development of denervation phenomena (increase in cross-section area of muscle fibers, changes in LDG spectrum).
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PMID:[Effect of trivalent iron on denervated skeletal muscles]. 294 27

The immunohistochemical location of cathepsin L in rabbit soleus, plantaris and psoas muscles was investigated using the peroxidase-anti-peroxidase (PAP) technique. The amount of enzyme detected varied according to the fibre type, which were identified by histochemical staining of serial sections for succinate dehydrogenase and alkali-stable myosin ATPase. In the three muscles studied labelling was strongest in the highly oxidative fibres and weaker in the other fibre types with least staining in the fast white fibres. Immunoreactive cathepsin L appeared to be most concentrated at the periphery of muscle fibres, especially near to the nuclei, although some staining was seen throughout the fibres.
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PMID:The immunohistochemical location of cathepsin L in rabbit skeletal muscle. Evidence for a fibre type dependent distribution. 295 26

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

Hindlimb suspension (HS) results in whole muscle atrophic and metabolic changes that vary in magnitude in different hindlimb muscles. The present study was designed to investigate these effects in single fibers. Fiber type and size and the activities of two metabolic marker enzymes were determined in a deep (close to the bone) and a superficial (away from the bone) region of the medial gastrocnemius (MG) and the tibialis anterior (TA) of control (CON) and 28-day HS adult female rats. Fibers were classified as dark or light adenosinetriphosphatase (ATPase) based on their qualitative staining reaction for myosin ATPase following alkaline preincubation. Fiber area and succinate dehydrogenase (SDH) and alpha-glycerophosphate dehydrogenase (GPD) activities were determined in tissue sections by use of an image analysis system. After 28 days of HS, the mean body weights of the CON and HS were similar. MG atrophied 28%, whereas TA weight was maintained in the HS. Both dark and light ATPase fibers in the deep region of the MG had smaller cross-sectional areas following HS, with the atrophic response being approximately twice as great in the light ATPase fibers. No significant changes in fiber type composition in either muscle or in fiber sizes in the superficial region of the MG or in either region of the TA were observed. Mean SDH activities of both fiber types were significantly lower in the MG and TA following HS. In contrast, mean GPD activities were either increased or maintained in light and dark ATPase fibers of both muscles in HS. Changes in SDH and GPD activity could not be directly linked to changes in fiber cross-sectional area. In summary, these data suggest an independence of the mechanisms determining muscle fiber size and metabolic adaptations associated with HS.
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PMID:Size and metabolic properties of fibers in rat fast-twitch muscles after hindlimb suspension. 295 35

Contractile properties and innervation patterns were determined in identified single fibers from the iliofibularis muscle of the desert iguana, Dipsosaurus dorsalis. Single fibers from both the red and white regions of the iliofibularis muscle were dissected along their length under oil and a portion was mounted on transducers for determination of maximum isometric tension (Po) and unloaded shortening velocity (Vmax) using the slack test method. Fibers were chemically skinned and activated by high Ca++. The remaining portion of the muscle fiber was mounted on a glass slide and histochemically treated to demonstrate myosin ATPase activity. Fibers studied functionally could therefore be classified as fast or slow according to their myosin ATPase activity, and they could also be classified metabolically according to the region of the muscle from which they were dissected. Fast-twitch glycolytic (FG) fibers from the white region and fast-twitch oxidative, glycolytic (FOG) and slow fibers from the red region had shortening velocities at 25 degrees C of 7.5, 4.4, and 1.5 l X s-1, respectively. Po did not differ in the three fiber types, averaging 279 kN X m-2. In a second experiment, 10 microns sections were examined every 30 microns through the proximal-most 7.5 mm of the iliofibularis muscle for motor endplates. Sections were stained to demonstrate regions of acetylcholinesterase activity. Fibers with visible endplates were classified in serial sections by histochemical treatment for myosin ATPase and succinic dehydrogenase. All slow fibers examined (n = 22) exhibited multiple endplates, averaging one every 725 microns.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Reptilian skeletal muscle: contractile properties of identified, single fast-twitch and slow fibers from the lizard Dipsosaurus dorsalis. 295 58

A line of Japanese quail selected for high body weight at 4 weeks of age (P line) was compared to an unselected control (C) line at 10, 23 and 56 days of age. The increase in the weight of the pectoralis major and supracoracoideus muscles in the P line was paralleled by an increase in total DNA, RNA and protein content of the muscles when compared to comparable age C line. DNA, RNA and protein concentrations and RNA/DNA and protein/DNA ratios were similar between lines within age. Greater muscle mass in the P line was accomplished primarily through an increase in the total number of muscle nuclei rather than through an increase in DNA unit size. Ca2+-activated myosin ATPase, total phosphorylase and succinic dehydrogenase enzyme activities were similar between lines and across ages in the pectoralis major and supracoracoideus muscles. The semimembranosus muscle possessed 59% more alpha fibers and only 7% more beta fibers in the P line when compared to the C line. Semimembranosus alpha fiber diameters were not significantly different between lines within age, while beta fiber diameters were significantly greater in the P line. Estimated beta fiber contribution to total semimembranosus muscle cross sectional area revealed no significant difference between lines within age. There was a significant increase in the length of the femur and humerus in the P line when compared to C line within age, indicating that some of the increased muscle weight of the P line quail was due to an increase in muscle length in addition to an increase in muscle cross-sectional area.
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PMID:An analysis of skeletal muscle response to selection for rapid growth in Japanese quail (Coturnix coturnix Japonica). 615 55

Histological and histochemical study was carried out to investigate disuse atrophy on skeletal muscle in adult albino rabbits. Untreated anterior tibial muscle and gastrocnemius muscle were studied. Three fiber types were recognized with myosin ATPase reaction, viz. type I, IIA and IIB fibers under a positive correlation with succinate dehydrogenase, phosphorylase, lactate dehydrogenase and NADH. TR stain. Statistical analysis in histogram of fiber diameter was also done. Soleus muscle mainly consisted of type I and type IIA fibers. As to developing skeletal muscle after birth in rabbits, especially in neonatal periods, type IIC fiber and also myotubes were demonstrated, with a gradual decrease in the process of growth. Fiber type ratio were examined in the anterior tibial and soleus muscle. In soleus muscle, type I fiber increased in numbers along with growth. Fibers, reacting with both ATPase pH 9.4 and SDH stain decreased in number. In the anterior tibial muscle, on the other hand, numbers of type I fiber were unremarkable, but all of the fibers were stained moderately with succinate dehydrogenase in neonatal periods, and fibers, with evident ATPase (pH 9.4) and SDH stain, decreased in numbers with growth. Instead, type IIB fibers appeared. Cast immobilization were applied on the legs of rabbits under three different positions, namely in so-called neutral, relaxed and stretched, in order to examine anterior tibial and gastrocnemius muscle respectively. In the neutral posture, three to four weeks after immobilization, decrease in size of type IIA fibers in the anterior tibial muscle was remarkable, whereas, in gastrocnemius muscle less than three weeks after immobilization type IIA and also type I fibers were involved predominantly. In gastrocnemius muscle under relaxed posture, type IIA and also type I fiber were decreased in fiber diameter only two weeks after immobilization, whereas, under stretched posture only type IIA fibers were involved three to four weeks after immobilization. In the anterior tibial muscle under stretched posture, same results were not obtained as in the gastrocnemius muscle. Less significant change of fiber type ratio was recognized in the anterior tibial muscle after four weeks immobilization.
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PMID:[Histochemical study on disuse atrophy of skeletal muscle in rabbit (author's transl)]. 617 50


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