DISTRIBUTION OF CHOLINESTERASE IN NORMAL HUMAN MUSCLE

1963 ◽  
Vol 41 (8) ◽  
pp. 1713-1720 ◽  
Author(s):  
J. Crispin Smith ◽  
Vera M. Foldes ◽  
Francis F. Foldes

The intracellular distribution of acetylcholinesterase and butyrylcholinesterase in biopsied human rectus abdominis and quadriceps femoris muscles was investigated. Differential ultracentrifugal fractionation showed that the highest specific activity of acetylcholinesterase was associated with the microsomal fraction, this enzyme being concentrated 19-fold compared to the original homogenate. The highest specific activity of butyrylcholinesterase was found in the non-particulate fraction. The mitochondrial fraction showed the lowest specific cholinesterase activity. Wide variation of cholinesterase activity was found in various autopsied muscles, the highest being oculomotor muscle and the lowest cardiac ventricular muscle. About 90% of the cholinesterase activity of skeletal muscle was due to acetylcholinesterase and 10% to butyrylcholinesterase.

1963 ◽  
Vol 41 (1) ◽  
pp. 1713-1720 ◽  
Author(s):  
J. Crispin Smith ◽  
Vera M. Foldes ◽  
Francis F. Foldes

The intracellular distribution of acetylcholinesterase and butyrylcholinesterase in biopsied human rectus abdominis and quadriceps femoris muscles was investigated. Differential ultracentrifugal fractionation showed that the highest specific activity of acetylcholinesterase was associated with the microsomal fraction, this enzyme being concentrated 19-fold compared to the original homogenate. The highest specific activity of butyrylcholinesterase was found in the non-particulate fraction. The mitochondrial fraction showed the lowest specific cholinesterase activity. Wide variation of cholinesterase activity was found in various autopsied muscles, the highest being oculomotor muscle and the lowest cardiac ventricular muscle. About 90% of the cholinesterase activity of skeletal muscle was due to acetylcholinesterase and 10% to butyrylcholinesterase.


1965 ◽  
Vol 97 (2) ◽  
pp. 389-392 ◽  
Author(s):  
G Vaes ◽  
P Jacques

1. When bone homogenates were fractionated according to the scheme developed for liver by de Duve, Pressman, Gianetto, Wattiaux & Appelmans (1955), all the enzymes assayed except cytochrome oxidase were found to occur partly in soluble and partly in particulate fractions. Among the particle-bound enzymes, the highest specific activity was found in the heavy-mitochondrial fraction for cytochrome oxidase, in the microsomal fraction for alkaline phenylphosphatase and in the light-mitochondrial fraction for eight acid hydrolases and for catalase. 2. Combined heavy-mitochondrial and light-mitochondrial fractions were subfractionated by isopycnic centrifugation in density gradients of sucrose or glycogen. In the various systems tried, cytochrome oxidase showed a relatively narrow distribution range with a sharp peak; the acid hydrolases and catalase showed flat and irregular distribution patterns, differing slightly in shape from one enzyme to the other. However, it was not possible to achieve a marked separation between the various enzymes under study. 3. It is concluded from these results that the acid hydrolases belong to special cytoplasmic particles, probably lysosomes, and that these particles are physically and enzymically heterogeneous. Catalase appears to be non-mitochondrial and could also belong to the lysosomes; but the possibility of an association with another type of particle must be kept in mind in view of what is known of liver catalase. Alkaline phenylphosphatase is largely attached to microsomal elements.


1974 ◽  
Vol 144 (2) ◽  
pp. 265-275 ◽  
Author(s):  
G S Cobon ◽  
P D Crowfoot ◽  
A W Linnane

The ability in vitro of yeast mitochondrial and microsomal fractions to synthesize lipid de novo was measured. The major phospholipids synthesized from sn-[2-3H]glycerol 3-phosphate by the two microsomal fractions were phosphatidylserine, phosphatidylinositol and phosphatidic acid. The mitochondrial fraction, which had a higher specific activity for total glycerolipid synthesis, synthesized phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylserine and phosphatidic acid, together with smaller amounts of neutral lipids and diphosphatidylglycerol. Phosphatidylcholine synthesis from both S-adenosyl[Me-14C]methionine and CDP-[Me-14C]choline appeared to be localized in the microsomal fraction.


1988 ◽  
Vol 251 (3) ◽  
pp. 881-885 ◽  
Author(s):  
J B Allred ◽  
C R Roman-Lopez

Biotinyl proteins were labelled by incubation of SDS-denatured preparations of subcellular fractions of rat liver with [14C]methylavidin before polyacrylamide-gel electrophoresis. Fluorographic analysis showed that mitochondria contained two forms of acetyl-CoA carboxylase [acetyl-CoA:carbon dioxide ligase (ADP-forming) EC 6.4.1.2], both of which were precipitated by antibody to the enzyme. When both forms were considered, almost three-quarters of the total liver acetyl-CoA carboxylase was found in the mitochondrial fraction of liver from fed rats while only 3.5% was associated with the microsomal fraction. The remainder was present in cytosol, either as the intact active enzyme or as a degradation product. The actual specific activity of the cytosolic enzyme was approx. 2 units/mg of acetyl-CoA carboxylase protein while that of the mitochondrial enzyme was about 20-fold lower, indicating that mitochondrial acetyl-CoA carboxylase was relatively inactive. Fractionation of mitochondria with digitonin showed that acetyl-CoA carboxylase was associated with the outer mitochondrial membrane. The available evidence suggests that mitochondrial acetyl-CoA carboxylase represents a reservoir of enzyme which can be released and activated under lipogenic conditions.


1996 ◽  
Vol 80 (6) ◽  
pp. 2051-2059 ◽  
Author(s):  
S. A. Binder-Macleod ◽  
S. C. Lee

This study examined the catchlike property of skeletal muscle during eccentric and concentric isovelocity contractions of fresh and fatigued quadriceps femoris muscles of 10 healthy subjects. During concentric contractions of fresh muscles, stimulation trains that elicited a catchlike response (CITs) produced greater force outputs and rates of rise force than comparable constant-frequency trains. These enhancements became more pronounced during fatigue. CITs were less effective in enhancing forces during eccentric contractions but did improve the rates of rise of force. Overall, the CIT that produced the greatest augmentation had a 5-ms initial interpulse interval. Proposed mechanisms for the catchlike property involve enhanced muscle stiffness for more efficient transmission of tension and increased calcium release. These results suggest that stimulation trains that take advantage of the catchlike property of skeletal muscle may be helpful during clinical applications where neuromuscular electrical stimulation is used to restore function in patients with damaged central nervous systems.


1980 ◽  
Vol 188 (2) ◽  
pp. 569-572 ◽  
Author(s):  
E J Barrett ◽  
N M Ryan ◽  
D R Headon

The influence of homogenization times on the presence of constituents in the microsomal fraction of skeletal muscle was investigated. Membranes having Ca2+-activated ATPase activity have a fragmentation pattern distinct from that of membranes displaying Ca2+-independent or basal ATPase activity. These latter membranes were found in highest specific concentration in the microsomal fraction prepared from homogenates subjected to short periods of homogenization. 5′-Nucleotidase (EC 3.1.3.5) activity paralleled that of basal ATPase on short periods of homogenization, as also did the specific concentration of cholesterol. Longer periods of homogenization led to a decrease in the specific activity of basal atpase, which reached its lowest value at 120s of homogenization, whereas the specific activity of 5′-nucleotidase and the specific concentration of cholesterol decreased initially in a similar manner to basal ATPase, but both increased substantially after the longest period of homogenization.


1983 ◽  
Vol 50 (03) ◽  
pp. 740-744 ◽  
Author(s):  
Nils Bergsdorf ◽  
Torbjörn Nilsson ◽  
Per Wallén

SummaryUtilizing the immunoglobulin fraction from a goat antiserum against human uterine tissue plasminogen activator, an enzyme- linked immunoassay for tissue-type plasminogen activator in human plasma has been developed. With the new method, the concentration of t-PA in normal human acidified plasma is found to be 4.0 ± 1.8 (SD) ng/ml. It increases to 12 ng/ml after a tomiquet test, and to 14 ng/ml after strenous physical exercise. In a group of patients with idiopathic thromboembolic disease, the resting t-PA concentration was 5 ng/ml and the post-occlusion value 16 ng/ml. Furthermore, the patients also exhibited a normal post-occlusion rise in the concentration of plasmin-α2-antiplasmin complex. However, in 37% of the post-occlusion patient plasmas, virtually no increase in t-PA could be detected by a specific activity assay. The results indicate that the reason for a defective post-occlusion fibrinolytic activity in a majority of cases may be the presence of increased concentrations of a fast-acting specific t-PA inhibitor.


1996 ◽  
Vol 351 (1346) ◽  
pp. 1455-1462 ◽  

The lateral frontal cortex is involved in various aspects of executive processing within short- and long-term memory. It is argued that the different parts of the lateral frontal cortex make distinct contributions to memory that differ in terms of the level of executive processing that is carried out in interaction with posterior cortical systems. According to this hypothesis, the mid-dorsolateral frontal cortex (areas 46 and 9) is a specialized system for the monitoring and manipulation of information within working memory, whereas the mid-ventrolateral frontal cortex (areas 47/12 and 45) is involved in the active retrieval of information from the posterior cortical association areas. Data are presented which support this two-level hypothesis that posits two distinct levels of interaction of the lateral frontal cortex with posterior cortical association areas. Functional activation studies with normal human subjects have demonstrated specific activity within the mid-dorsolateral region of the frontal cortex during the performance of tasks requiring monitoring of self-generated and externally generated sequences of responses. In the monkey, lesions restricted to this region of the frontal cortex yield a severe impairment in performance of the above tasks, this impairment appearing against a background of normal performance on several basic mnemonic tasks. By contrast, a more severe impairment follows damage to the mid-ventrolateral frontal region and functional activation studies have demonstrated specific changes in activity in this region in relation to the active retrieval of information from memory.


2019 ◽  
Vol 105 (2) ◽  
pp. 557-566 ◽  
Author(s):  
Kittichate Visuttijai ◽  
Carola Hedberg-Oldfors ◽  
Christer Thomsen ◽  
Emma Glamuzina ◽  
Cornelia Kornblum ◽  
...  

Abstract Context Glycogenin is considered to be an essential primer for glycogen biosynthesis. Nevertheless, patients with glycogenin-1 deficiency due to biallelic GYG1 (NM_004130.3) mutations can store glycogen in muscle. Glycogenin-2 has been suggested as an alternative primer for glycogen synthesis in patients with glycogenin-1 deficiency. Objective The objective of this article is to investigate the importance of glycogenin-1 and glycogenin-2 for glycogen synthesis in skeletal and cardiac muscle. Design, Setting, and Patients Glycogenin-1 and glycogenin-2 expression was analyzed by Western blot, mass spectrometry, and immunohistochemistry in liver, heart, and skeletal muscle from controls and in skeletal and cardiac muscle from patients with glycogenin-1 deficiency. Results Glycogenin-1 and glycogenin-2 both were found to be expressed in the liver, but only glycogenin-1 was identified in heart and skeletal muscle from controls. In patients with truncating GYG1 mutations, neither glycogenin-1 nor glycogenin-2 was expressed in skeletal muscle. However, nonfunctional glycogenin-1 but not glycogenin-2 was identified in cardiac muscle from patients with cardiomyopathy due to GYG1 missense mutations. By immunohistochemistry, the mutated glycogenin-1 colocalized with the storage of glycogen and polyglucosan in cardiomyocytes. Conclusions Glycogen can be synthesized in the absence of glycogenin, and glycogenin-1 deficiency is not compensated for by upregulation of functional glycogenin-2. Absence of glycogenin-1 leads to the focal accumulation of glycogen and polyglucosan in skeletal muscle fibers. Expression of mutated glycogenin-1 in the heart is deleterious, and it leads to storage of abnormal glycogen and cardiomyopathy.


Blood ◽  
2001 ◽  
Vol 97 (1) ◽  
pp. 130-138 ◽  
Author(s):  
Valder R. Arruda ◽  
James N. Hagstrom ◽  
Jeffrey Deitch ◽  
Terry Heiman-Patterson ◽  
Rodney M. Camire ◽  
...  

Abstract Recent data demonstrate that the introduction into skeletal muscle of an adeno-associated viral (AAV) vector expressing blood coagulation factor IX (F.IX) can result in long-term expression of the transgene product and amelioration of the bleeding diathesis in animals with hemophilia B. These data suggest that biologically active F.IX can be synthesized in skeletal muscle. Factor IX undergoes extensive posttranslational modifications in the liver, the normal site of synthesis. In addition to affecting specific activity, these posttranslational modifications can also affect recovery, half-life in the circulation, and the immunogenicity of the protein. Before initiating a human trial of an AAV-mediated, muscle-directed approach for treating hemophilia B, a detailed biochemical analysis of F.IX synthesized in skeletal muscle was carried out. As a model system, human myotubes transduced with an AAV vector expressing F.IX was used. F.IX was purified from conditioned medium using a novel strategy designed to purify material representative of all species of rF.IX in the medium. Purified F.IX was analyzed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE), N-terminal sequence analysis, chemical γ-carboxyglutamyl analysis, carbohydrate analysis, assays for tyrosine sulfation, and serine phosphorylation, and for specific activity. Results show that myotube-synthesized F.IX has specific activity similar to that of liver-synthesized F.IX. Posttranslational modifications critical for specific activity, including removal of the signal sequence and propeptide, and γ-carboxylation of the N-terminal glutamic acid residues, are also similar, but carbohydrate analysis and assessment of tyrosine sulfation and serine phosphorylation disclose differences. In vivo experiments in mice showed that these differences affect recovery but not half-life of muscle-synthesized F.IX.


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