Reference Interval for Lactate Dehydrogenase Catalytic Activity in Serum Measured According to the New IFCC Recommendations

2003 ◽  
Vol 41 (7) ◽  
Author(s):  
Franca Pagani ◽  
Roberto Bonora ◽  
Mauro Panteghini
Keyword(s):  
Catalytic Activity ◽  
Lactate Dehydrogenase ◽  
Reference Interval

Lactate dehydrogenase isoenzyme 1 with the centrifugal analyzer after immunochemical removal of other isoenzymes.

1981 ◽  
Vol 27 (6) ◽  
pp. 922-923 ◽  
Author(s):  
D E Bruns ◽  
J C Emerson ◽  
R L Bertholf ◽  
K E Hill ◽  
J Savory
Keyword(s):  
Lactate Dehydrogenase ◽  
Reference Interval ◽  
Enzymic Activity ◽  
The Other ◽  
Dehydrogenase Isoenzyme

Abstract We describe a centrifugal analyzer method for measuring the LD-1 isoenzyme of lactate dehydrogenase (EC 1.1.1.27) in serum, after immunochemical precipitation of the other four isoenzymes. Enzymic activity was measured kinetically at 30 degrees C with the pyruvate-to-lactate assay. The method for LD-1 was linear to 1000 U/L. The precision (CV) of the assay was 1.0--2.2% within-run and 3.1--4.5% day-to-day. The reference interval was 26--73 U/L (n = 51), corresponding to 21--35% of total LD activity.

Creatine measurement in serum and urine with an automated enzymatic method

1993 ◽  
Vol 39 (8) ◽  
pp. 1613-1619 ◽  
Author(s):  
C Beyer
Keyword(s):  
Creatine Kinase ◽  
Lactate Dehydrogenase ◽  
Pyruvate Kinase ◽  
Present Method ◽  
Comparative Method ◽  
Reference Interval ◽  
Enzymatic Method ◽  
Men And Women ◽  
Enzymatic Procedure ◽  
Serum And Urine

Abstract I describe an automated enzymatic procedure to quantitate creatine in both serum and urine. In this assay, which requires no pretreatment of the sample, creatine kinase (CK; EC 2.7.3.2) and pyruvate kinase (EC 2.1.7.40) are used as auxiliary enzymes and lactate dehydrogenase (EC 1.1.1.27) is used in the indicator reaction. CK is also used as the starting reagent. Data obtained with the present method for creatine measurement in serum were compared with those from the Jaffé method and an enzymatic method: y = 1.13x - 7.58, SE = 4.48, and r = 0.925 (Jaffé); and y = 1.17x + 2.73, SE = 5.06, and r = 0.962 (enzymatic); for creatine measurement in urine: y = 0.63x + 39.74, SE = 296.7 and r = 0.719 (Jaffé). The present method provides improved precision: the total CVs for serum, determined by the present and comparative methods, respectively, were 3.5-8.9%, 8.2-43.0%, and 5.3-16%; for urine, the CVs were 3.3-5.1% and 9.6-21.2% for the present and comparative method, respectively. I established the normal reference interval as 13-74 and 13-89 mumol/L for creatine in serum, and as 175-700 and 150-1200 mumol/24 h for creatine in urine for men and women, respectively.

Enhancement of the catalytic activity of d-lactate dehydrogenase from Sporolactobacillus laevolacticus by site-directed mutagenesis

2018 ◽  
Vol 133 ◽  
pp. 214-218
Author(s):  
Kento Nakano ◽  
Shoichi Sawada ◽  
Ryosuke Yamada ◽  
Takashi Mimitsuka ◽  
Hiroyasu Ogino
Keyword(s):  
Catalytic Activity ◽  
Lactate Dehydrogenase ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis

Catabolism of plasma enzymes, as studied with 125I-labeled lactate dehydrogenase-1 in the rabbit.

1976 ◽  
Vol 22 (8) ◽  
pp. 1269-1276
Author(s):  
J H Wilkinson ◽  
A R Qureshi
Keyword(s):  
Enzyme Activity ◽  
Small Intestine ◽  
Catalytic Activity ◽  
Lactate Dehydrogenase ◽  
Extracellular Fluid ◽  
Second Phase ◽  
Enzyme Protein ◽  
Plasma Enzymes ◽  
Close Proximity ◽  
Intestinal Contents

Abstract Circulating enzymes may be inactivated in the plasma and the inactive breakdown products may be hydrolyzed in the lumen of the small intestine. Evidence for this mechanism was based upon previous studies with 125I-labeled lactate dehydrogenase-5, and here similar studies with radioiodinated lactate dehydrogenase-1 are reported, to determine whether this isoenzyme is similarly catabolized. The pure rabbit enzyme was labeled with 125I by use of lactoperoxidase and hydrogen peroxide (the labeled enzyme had 80-85% of the original catalytic activity). After its intravenous injection into rabbits, plasma enzyme activity and radioactivity disappeared during the first 4 h at similar fast rates, apparently because of distribution of the injected enzyme throughout the extracellular fluid. During a second phase (30-h), catalytic activity disappeared significantly faster than radioactivity, suggesting inactivation of the enzyme in either the plasma or a compartment in close proximity to it, or both. Enzyme activity then remained constant while plasma radioactivity continued to decrease at a slower, exponential rate, apparently owing to removal of breakdown products. In no case did tissue radioactivity, studied 6 h after injection, approach that of plasma. We therefore conclude that removal of the enzyme protein or its breakdown products is a passive process. Appreciable radioactivity was detected in the intestinal contents, a finding which suggests that removal via the small intestine is an important route for the removal of inactivated enzyme products from the circulation. Less than 3% of the injected radioactivity appeared in the feces during the first three days; urinary excretion accounted for about 67% during the same period, about 60% of which consisted of radio-iodinated amino-acids, the remainder of iodide. Free mono- and di-iodotyrosines were among the products excreted. These appear to originate from absorption of the products of further breakdown of the enzyme molecule in the intestine.

Lactate dehydrogenase isoenzymes in serum during recent acute myocardial infarction.

1987 ◽  
Vol 33 (8) ◽  
pp. 1419-1420 ◽  
Author(s):  
Z Rotenberg ◽  
I Weinberger ◽  
A Sagie ◽  
J Fuchs ◽  
O Sperling ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Lactate Dehydrogenase ◽  
Normal Values ◽  
Myocardial Necrosis ◽  
Reference Interval ◽  
Total Serum ◽  
Recent Myocardial Infarction ◽  
Complicated Course ◽  
Recent Acute Myocardial Infarction ◽  
Lactate Dehydrogenase Isoenzymes

Abstract Lactate dehydrogenase (LD, EC 1.1.1.27) isoenzymes 1 and 2 and the LD 1:2 ratio were determined in 62 patients with recent myocardial infarction 24, 48, and 72 h after total serum LD activity had returned to normal values. From the results we could define two groups of patients. The first, 40 patients in whom proportions of LD-1 and LD-2 isoenzymes in serum and the LD 1:2 ratio were all within the normal reference interval, all had an uncomplicated course of recovery from myocardial infarction. In the remaining 22 patients, LD-1 still exceeded LD-2 24 to 72 h after total LD activity returned to normal values; i.e., the ratio was similar to that in patients with myocardial infarction. Seven of these 22 patients (32%) had a complicated course, with re-infarction in all seven. Thus, even in the presence of normal total LD activity, a high LD 1:2 ratio may reflect a consistent focal myocardial necrosis in some patients with recent myocardial infarction and may serve as an early marker for further re-infarction.

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