Blood serum enzymes

A2. Abul-Fadl, M. A. M., and Metwalli, 0. M., Studies on certain urinary and blood serum enzymes in bilharziasis and their possible relation to bladder cancer in Egypt. Brit J. Cancer 17, 137-141 (1963). 

Diagnostically Useful Assays of Blood Serum Enzymes ... 

The primary health care provider may also order laboratory and diagnostic tests, renal and hepatic function tests, complete blood count, serum enzymes, and serum electrolytes. The nurse reviews these test results before the first dose is given and reports any abnormalities to the primary health care provider. The patient is usually placed on a cardiac monitor before aiitiarrhytiuiric drug therapy is initiated. The primary health care provider may order an ECG to provide baseline data for comparison during therapy. 

Along with an effective electrolyte and screening program for genetic disease, the laboratory of Neonatology needs to have the capability of analyzing for other components in blood serum, which aid in the diagnosis of disease. These include such determinations as alkaline phosphatase, and various other enzymes, creatinine, uric acid and a host of other components which are normally assayed by the main clinical laboratory. 

Sample Collection and Enzyme Stability. Serum samples are collected with chemically clean, sterile glassware. Blood is allowed to clot at room temperature, the clot is gently separated from the test tube with an applicator stick, and the blood is centrifuged for 10 minutes at 1,000 g. If the red cells are known to contain the enzymes whose activity is being measured, as in the case of LD, even slightly hemolyzed serums must be discarded. When acid phosphatase is to be measured, the serum should be placed immediately in ice and processed as soon as possible, or it should be acidified by the addition of a small amount of sodium citrate. Anticoagulants such as EDTA, fluoride and oxalate inhibit some serum enzymes. However, heparin activates serum lipoprotein lipase. 

Materials required AChE preparations, commercial acetylcholinesterase, horse (blood) serum preparation, human (blood) serum preparation, or matrix biotests with these immobilized enzyme (see section 15.2.1)... 

Elevated blood and serum enzyme levels in rats fed 0.5 mg mirex/kg ration for 28 days (Yarbrough et al. 1981)... 

Since the enzyme solution used for the assay consists of different media (e.g., blood, serum, urine, cerebrospinal fluid, tissue homogenate, saliva), the activity must be related to different volumetric or gravimetric units. 

None of the exposures produced changes in clinical chemistry values (blood count, blood nitrate, blood urea nitrogen, serum enzymes, and serum electrolytes or urinalysis and nitrate and nitrite urinary excretion), spontaneous electrical activity of the cortex of the brain (detected by EEG), pulse rate and sinus rhythm, or pulmonary function. Visual and auditory acuity, exercise EKG, and time estimation tests did not differ from control values for any of the exposures. Only one of several cognitive tests was affected by exposure and the change occurred only in the four subjects exposed at 1.5 ppm. The test was taken during the time the subjects were experiencing severe headaches. 

There is some confusion in the literature regarding the substances designated as anti-choline-esterases (usually shortened to anticholinesterases). The term cholinesterase was first used1 in connexion with an enzyme present in the blood serum of the horse which catalysed the hydrolysis of acetylcholine and of butyrylcholine, but exhibited little activity towards methyl butyrate,... 

Thus a distinction was provided between simple esterases, such as fiver esterase, which catalysed the hydrolysis of simple aliphatic esters but were ineffective towards choline esters. The term 1 cholinesterase was extended to other enzymes, present in blood sera and erythrocytes of other animals, including man, and in nervous tissue, which catalysed the hydrolysis of acetylcholine. It was assumed that only one enzyme was involved until Alles and Hawes2 found that the enzyme present in human erythrocytes readily catalysed the hydrolysis of acetylcholine, but was inactive towards butyrylcholine. Human-serum enzyme, on the other hand, hydrolyses butyrylcholine more rapidly than acetylcholine. The erythrocyte enzyme is sometimes called true cholinesterase, whereas the serum enzyme is sometimes called pseudo-cholinesterase. Stedman,3 however, prefers the names a-cholinesterase for the enzyme more active towards acetylcholine, and / -cholinesterase for the one preferentially hydrolysing butyrylcholine. Enzymes of the first type play a fundamental part in acetylcholine metabolism in vivo. The function of the second type in vivo is obscure. Not everyone agrees with the designation suggested by Stedman. It must also be stressed that enzymes of one type from different species are not always identical in every respect.4 Furthermore,... 

Transaminases are also found in other tissues, from which they leak from the cells into the blood when injury occurs. Measurement of serum enzyme activity (serum enzyme diagnosis see also p. 98) is an important method of recognizing and monitoring the course of such injuries. Transaminase activity in the blood is for instance important for diagnosing liver disease (e.g., hepatitis) and myocardial disease (cardiac infarction). 

Serum alkaline phosphatase elevations have been reported following administration of salt-poor albumin (B5). Placenta is very rich in a heat-stable alkaline phosphatase, and albumin prepared from placental blood has a high activity of this enzyme. In one cirrhotic patient who received 1-6 units per day of albumin obtained from pooled human blood and/or human placenta, the alkaline phosphatase before infusion was 5 Bodansky units and by the thirteenth day of administration had reached a value of 160 units. The physician administering the albumin at first thought the patient was having a severe toxic liver reaction and stopped the therapy. The alkaline phosphatase then started to go down and within 10 days returned to normal levels. Analysis of the albumin indicated that it contained 470 units of alkaline phosphatase activity and was probably responsible for the observed elevations in the serum enzyme activity. Albumin prepared from venous blood did not cause an alkaline phosphatase elevation, but placenta-albumin caused elevations with a half-life of about 8 days (Ml). 

Encephalopathic syndrome - An encephalopathic syndrome (characterized by weakness, lethargy, fever, tremulousness, confusion, extrapyramidal symptoms, leukocytosis, elevated serum enzymes, blood urea nitrogen, fasting blood sugar) has occurred in a few patients treated with lithium plus an antipsychotic (haloperidol). 

The multi-copper oxidases include laccase, ceruloplasmin, and ascorbate oxidase. Laccase can be found in tree sap and in fungi ascorbate oxidase, in cucumber and related plants and ceruloplasmin, in vertebrate blood serum. Laccases catalyze oxidation of phenolic compounds to radicals with a concomitant 4e reduction of O2 to water, and it is thought that this process may be important in the breakdown of lignin. Ceruloplasmin, whose real biological function is either quite varied or unknown, also catalyzes oxidation of a variety of substrates, again via a 4e reduction of O2 to water. Ferroxidase activity has been demonstrated for it, as has SOD activity. Ascorbate oxidase catalyzes the oxidation of ascorbate, again via a 4e reduction of O2 to water. Excellent reviews of these three systems can be found in Volume 111 of Copper Proteins and Copper Enzymes (Lontie, 1984). 

An enzyme present in blood serum of the horse. Biochem. J. 26 2056-2066, 1932. 

Sialyltransferases can be solubilized from their subcellular site by using detergents, and be purified by affinity chromatography on, for example, CDP-6-aminohexanol-agarose,267 as already described. Solubilization of frog- and rat-liver sialyltransferases by means of Triton X-100 has been described.27 Soluble sialyltransferase occurs in colostrum, and is also present in small quantities in normal blood-serum. From the latter source, the enzyme was purified 300-fold by poly (acrylamide) gel-electrophoresis.2 ... 

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