The Meaning of Enzyme Activity Measurements in Human Tissues

2015 ◽  
pp. 3-7
Author(s):  
J. Frei
Keyword(s):  
Enzyme Activity ◽  
Human Tissues ◽  
Activity Measurements

Xanthine Oxidoreductase Gene Expression and Enzyme Activity in Developing Human Tissues

Neonatology ◽  
1998 ◽  
Vol 74 (4) ◽  
pp. 274-280 ◽  
Author(s):  
Mika Saksela ◽  
Risto Lapatto ◽  
Kari O. Raivio
Keyword(s):  
Gene Expression ◽  
Enzyme Activity ◽  
Xanthine Oxidoreductase ◽  
Human Tissues

scholarly journals Immunoassay of muscle-specific creatine kinase with a monoclonal antibody and application to myogenesis and muscular dystrophy

1983 ◽  
Vol 213 (2) ◽  
pp. 417-425 ◽  
Author(s):  
G E Morris ◽  
L P Head
Keyword(s):  
Monoclonal Antibody ◽  
Creatine Kinase ◽  
Enzyme Activity ◽  
Total Protein ◽  
Plasma Concentrations ◽  
Thigh Muscle ◽  
Cell Protein ◽  
Enzyme Linked Immunosorbent Assay ◽  
Activity Measurements

A competition e.l.i.s.a. (enzyme-linked immunosorbent assay) is described that enables direct measurement of the muscle-specific polypeptide of chick creatine kinase (M-CK) in extracts of differentiating muscle-cell cultures and in blood plasma samples, even in the presence of embryonic, or brain-type, creatine kinase. The characteristics of the assay can be considerably improved by the use of a monoclonal antibody, CK-ART, instead of rabbit antisera, and we offer an explanation for this in terms of heterogeneity of antibody affinities in polyclonal antisera. In addition to native enzyme, the assay will measure creatine kinase unfolded and inactivated by 8 M-urea treatment. During chick muscle differentiation in vitro, M-CK increased from 7.5% of the total creatine kinase at 24h to 76.0% at 143h, in good agreement with isoenzyme separation data. As a percentage of the total cell protein, M-CK increased by 156-340-fold over the same period and constituted 0.38-0.56% of the total protein in late cultures. E.l.i.s.a. measurements on 17-20-day embryonic thigh-muscle extracts, which contain almost exclusively M-CK, agree well with enzyme activity and radioimmunoassay. M-CK constituted 0.7-1.6% of the total protein in 17-19-day embryonic thigh muscle. Plasma M-CK concentrations in normal 2-8-week-old chickens were found to be in the range 0.5-0.9 micrograms/ml. Plasma concentrations of 32-56 micrograms/ml were found in 8-week-old dystrophic chickens by both e.l.i.s.a. and enzyme-activity measurements. The results suggest that inactive or unfolded forms of M-CK do not normally exist, in any significant amounts, in cell and tissue extracts or in freshly prepared samples of plasma.

Abstract WP153: Post-Stroke Physical Exercise Improves Cognition in Middle-Aged Female Rats

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Sharnikha Saravanan ◽  
Weizhao Zhao ◽  
Kunjan R Dave ◽  
Miguel A Perez-Pinzon ◽  
Ami P Raval
Keyword(s):  
Enzyme Activity ◽  
Physical Exercise ◽  
Cognitive Decline ◽  
Fear Conditioning ◽  
Enzyme Activities ◽  
Female Rats ◽  
Male Rats ◽  
Mitochondrial Enzyme ◽  
Post Stroke ◽  
Activity Measurements

Background: A woman’s risk of a stroke increases exponentially following the onset of menopause, andpost-stroke cognitive decline is a significant consequence of stroke survivors. Our earlier study demonstrated that physical exercise (PE) reduced post-stroke brain injury and improved cognitive functions in male rats. The focus of our study is on the improvement of post-stroke cognitive function in female rats. Methods: Reproductively senescent Sprague-Dawley female rats were exposed to transient middle cerebral artery occlusion (tMCAO; 90 min) and randomly assigned to either PE or sham-PE groups. After 3-5 days, rats underwent sham-PE (0m/min speed) or PE (15m/min speed) for 30 mins either every day (continuous) or alternate day for five times on treadmill. The rats that underwent the alternate day paradigm were treated with ER-β agonist (DPN; 1mg/kg) or vehicle-DMSO immediately following PE/sham-PE sessions to determine the synergistic effect. Twenty-one days after the last PE/sham-PE, rats were tested for hippocampal-dependent contextual fear conditioning and freeze time was measured. Rat brains were processed for histology and infarct area was measured with MCID software. From a separate cohort of rat subjected to PE or sham-PE, brain tissue was harvested for various biochemical assays and mitochondrial enzyme activity measurements. Results: Post-tMCAO continuous PE did not reduce ischemic damage. However, alternate PE regimen with or without ER-β agonist reduced infract volume by 20% (p < 0.05) and 23% (p < 0.05), respectively as compared to no-PE. Similarly, alternate PE showed increased freezing on the second day of fear conditioning by 15% (p < 0.05), indicating improved spatial memory. Individual mitochondrial complex I, II, III and IV enzyme activity measurements demonstrated significant improvement in complex III-IV enzyme activities in the alternate PE treated group as compared to sham-PE. Conclusion: An alternate day PE paradigm and ER-β activation improves post-stroke mitochondrial enzyme activities and cognition in reproductively senescent female rats. Future studies delineating underlying mechanism could help identify therapies to prevent/reduce cognitive decline in menopausal female stroke patients.

scholarly journals Measurement of 1-aspartamido-β-N-acetylglucosamine amidohydrolase activity in human tissues

1977 ◽  
Vol 163 (1) ◽  
pp. 9-14 ◽  
Author(s):  
B Dugal
Keyword(s):  
Enzyme Activity ◽  
Incubation Time ◽  
Human Liver ◽  
Enzyme System ◽  
Total Concentration ◽  
Reaction Times ◽  
Human Tissues ◽  
Human Organs ◽  
Crude Homogenate ◽  
Enzyme Fraction

The activity of 1-aspartamido-beta-N-acetylglucosamine amidohydrolase (aspartylglucosylaminase, EC 3.5.1.26) was measured in normal and diseased human liver, brain and kidney. Organs from patients with aspartylglucosaminuria show very little activity. Crude homogenates of human organs show a reaction catalysed by a complex enzyme system. With homogenate, the formation of product was linear with time up to about 6 h. Reaction times longer than 6-7h resulted in a decrease in the total concentration of product. This phenomenon was not found with the partially purified enzyme fraction. Linearity of the enzyme activity with different protein concentrations was found, independent of the incubation time. Longer incubation of the crude homogenate resulted in the utilization of the product, N-acetylglucosamine. This phenomenon was not observed with the partially purified enzyme fraction. This amidase from human organs differs from that obtained from other sources and apparently represents a rather complex enzyme system.

Relation Between Acid Proteinase Activity and Redistribution of Nitrogen During Grain Development in Wheat

1976 ◽  
Vol 3 (6) ◽  
pp. 721 ◽  
Author(s):  
MJ Dalling ◽  
G Boland ◽  
JH Wilson
Keyword(s):  
Enzyme Activity ◽  
Nitrogen Removal ◽  
Nitrogen Loss ◽  
Proteinase Activity ◽  
Acid Proteinase ◽  
Wheat Cultivars ◽  
Grain Development ◽  
Significant Relation ◽  
Activity Measurements ◽  
Grain Nitrogen

Accumulation of grain nitrogen was studied in the wheat cultivars Argentine IX and Insignia. The pattern of nitrogen removal from several tissues of each cultivar was compared with the pattern of acid proteinase activity. There was a highly significant relation between the rate of nitrogen loss from the tissues and the rate estimated from the enzyme activity measurements. This suggests an important role for acid proteinase enzymes in leaf senescence. Redistribution of nitrogen present in the plant at anthesis accounted for 78.5 and 80.6 % of the final grain nitrogen yield of Argentine IX and Insignia respectively.

scholarly journals Fast and accurate enzyme activity measurements using a chip-based microfluidic calorimeter

2018 ◽  
Vol 544 ◽  
pp. 57-63 ◽  
Author(s):  
Morten M.C.H. van Schie ◽  
Kourosh Honarmand Ebrahimi ◽  
Wilfred R. Hagen ◽  
Peter-Leon Hagedoorn
Keyword(s):  
Enzyme Activity ◽  
Activity Measurements

Amperometric Microcell for Enzyme Activity Measurements

1998 ◽  
Vol 70 (10) ◽  
pp. 2156-2162 ◽  
Author(s):  
Geza Nagy ◽  
Clarke X. Xu ◽  
Richard P. Buck ◽  
Erno Lindner ◽  
Michael R. Neuman
Keyword(s):  
Enzyme Activity ◽  
Activity Measurements
Sign in / Sign up

Export Citation Format

Share Document