Enzymes in serum

Roy, A. V. Brown, M. E. and Hayden, J. E. Sodium thymolphthalein monophosphate, a new acid phosphatase substrate with greater specificity for the prostatic enzyme in serum. Clin. Chem. (1971), IJ, 1093-1102. 

Tab. 6-4 RMs for proteins in serum (i), enzymes in serum (2), lipids and other in serum (3), pure and purified materials (4)...

Elevated activities of liver enzymes (lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, glutamate dehydrogenase) were found in the serum of rats exposed continuously to 26 ppm phenol vapor for 15 days (Dalin and Kristoffersson 1974). Increased concentration of these enzymes in serum is often associated with liver injury but is not conclusive evidence for the type or severity of injury. Therefore, 26 ppm can be considered a less serious LOAEL in rats. Serum levels of... 

Hepatic Effects. An increase in serum iron, which may reflect an adverse liver effect, was observed in workers exposed for 6 months to phenol in a wood treatment liquid (Baj et al. 1994). Elevated concentrations of hepatic enzymes in serum, and an enlarged and tender liver suggestive of liver injury, were reported in an individual who had been exposed repeatedly to phenol vapor for 13.5 years (Merliss 1972). Since phenol was also spilled on his clothes resulting in skin irritation, dermal and inhalation exposures were involved. A 2-fold increase in serum bilirubin was observed in a man who was accidentally splashed with a phenol solution over his face, chest wall, hand, and both arms (Horch et al. 1994). Changes in liver enzymes were not observed in persons exposed to phenol in drinking water for several weeks after an accidental spill (Baker et al. 1978). This study is not conclusive because the measurements were completed 7 months after the exposure. 

Hepatotoxicity, characterized histologically by centrilobular necrosis, and elevated hepatic enzymes in serum were reported in separate studies in which laboratory animals were exposed to phenol in air at concentrations 26 ppm (Dalin and Kristoffersson 1974 Deichmann et al. 1944). Hepatic effects were not observed in monkeys, rats, or mice exposed to 5 ppm phenol in air continuously for 90 days (Sandage 1961). Hepatic effects have also not been observed in rodents following oral exposure to phenol (Berman et al. 1995 Hsieh et al. 1992 Jones-Price et al. 1983a, 1983b NCI 1980). 

Musculoskeletal Effects. Dramatic musculoskeletal effects as evidenced by elevated muscle enzymes in serum occurred in two patients exposed by the dermal and inhalation routes (Letz et al. 1984). No musculoskeletal effects were reported in humans exposed by other routes or in experimental animals. Risks appear to be negligible for adverse musculoskeletal effects in humans exposed to low levels of 1,2-dibromoethane. 

Mitochondrial diseases may be manifest as ready fatigability elevated lactic acid levels In blood Increased muscle enzymes In serum ataxia and a variety of neurosensory deficits. Including blindness and deafness. 

In cases of low -glucuronidase activity, the activity of this enzyme in serum should also be assessed to avoid missing I - cell disease. 

Finally, mass spectrometric determination of the phosphonylated peptic nonapeptide from butyrylcholinesterase allowed the positive identification of sarin-inhibited enzyme in serum samples from several Japanese victims of the Tokyo subway attack (see Figure 10). 

In recent years, the importance of enzyme levels in body fluids for clinical diagnosis has been recognized. It has been established that activities of secreted enzymes and cellular enzymes in serum are a sensitive indication of the pathophysiological condition of the body. Specific and sensitive substrates play a prominent role for this purpose. Fluorogenic substrates, e.g., enable sensitive micro-analyses. 

C for 15 to 60 minutes before centrifuging for 2 minutes and injecting 20 fiL on the column. To assay the enzyme in serum 20 /tL aliquots were removed from the assay mixture and injected directly. 

The assay is suitable for assaying enzyme in serum and plasma, and also recombinant human prorenin expressed in Chinese hamster ovary cells. Prorenin was activated by trypsin digestion. 

GGT activity in serum comes primarily from liver. The enzyme in serum is heterogeneous with respect to both net molecular charge (e.g., shown by electrophoresis) and size. These forms appear to derive from posttranslational modifications of a single type of enzyme molecule rather than to be due to the existence of true isoenzymes. For example, high molecular weight forms may represent the release of cell membrane fragments into the circulation. Despite numerous investigations, clear correlations between patterns of multiple forms and particular diseases cannot be discerned. 

Schumann G, Klauke R, New IFCC reference procedures for the determination of catalytic activity concentrations of five enzymes in serum preliminary upper reference Emits obtained in hospitalized subjects. Chn Chim Acta 2003 327 ... 

In patients with epithelial ovarian carcinomas, serum Mn-SOD levels increased in accordance with the clinical progression of disease. At the early stage, however, the incidence of cases with elevated serum levels was low. Therefore measurements of serum Mn-SOD may not always be useful for the early diagnosis of epithelial ovarian carcinoma. The decline in serum Mn-SOD levels following affective therapy seems to reflect the disappearance of lesions. Decreases occurred after therapy and increases occurred with recurrences. Thus it appears that the measurement of this enzyme in serum can provide useful data for monitoring epithelial ovarian cancer following therapy, and for the early diagnosis of recurrences of the disease. 

Binding those metal ions in a metalloprotein usually prevents them from entering into these types of reactions. For example, transferrin, the iron-transport enzyme in serum, is normally only 30 percent saturated with iron. Under conditions of increasing iron overload, the empty iron-binding sites on transferrin are observed to fill, and symptoms of iron poisoning are not observed in vivo until after transferrin has been totally saturated with iron. Ceruloplasmin and metallothionein may play a similar role in preventing copper toxicity. It is very likely that both iron and copper toxicity are largely due to catalysis of oxidation reactions by those metal ions. 

The activity of these enzymes in serum following an Ml is shown in Figure 3. Creatine kinase levels rise rapidly, peaking at 24 h. with slower rises being show ii by A.ST and l.DH. The more rapid fall in CK also allows for its use in the diagnosis of... 

Korsrud, G. O., and K. D. Trick. 1973. Activities of several enzymes in serum and heparinized plasma from rats. Clinica ChimicaActa... 

LEVELS OF SOME PROTEINS AND ENZYMES IN SERUM AND URINE (after Herber et al.. 1988)... 

Figure 2. Concentration of one metabolite and two enzymes in serum of Packy during a musth episode, (a) Serum creatinine, 1994. (b) Serum creatinine phosphokinase, 1994. (c) Serum gamma glutamyl transferase (GGT), 1994—95. Arrows as in Figure 1.

Only a few enzymes are specifically secreted by organs into the blood stream. These are the enzymes of blood coagulation, cholinesterase, and amylase [21]. Serum, in the main, is a passive receptacle for enzymes derived from the tissue cells and the formed elements of blood. Normally, the level of enzymes in serum is both low and constant. Since most of the enzymes present are derived from cells, it follows that these enzymes must be able to pass through the limiting membrane of the parent cell. This outward passage is accomplished either by diffusion through pores or alternatively by the aid of an active transport system. Except in those cases where enzyme secretion is a physiological process, active transport is unlikely. The loss of enzymes from cells is accelerated by tissue injury, and also by metabolic inhibitors like 2,4-dinitrophenol, iodoacetate, and carbon monoxide [22]. The implication that the retention by the cell of a... 

Isoenzymes should become a valuable means of establishing the tissue origins of enzymes in serum. That this has not always been successfully accomplished stems very largely from the fact that isoenzyme forms are often not easy to separate. Sometimes, the required electrophoretic, chromatographic, or immunological procedures are not easily transplanted from their laboratories of origin. 

K. S. Henley, E. Schmidt and F.W. Schmidt, Enzymes in Serum (C.C. Thomas, Spring-field, 1966). 

TABLE 2. Concentration of Proteins and Enzymes in Serum and Urine Information Important for Assessment Tubular and Glomerular Kidney Damage... 

Cobalamin analogues Cobalamin analogues are cobalamin-related molecules not able to act as coenzymes for the cobalamin dependent human enzymes. In serum, both cobalamin and cobalamin analogues are present. The protein transcobalamin can only bind active forms of cobalamin, whereas the protein haptocorrin can bind both cobalamins and analogues. 

Gamma-glutamyl transferase. This enzyme is located in cell plasma membranes of several tissues, with the highest levels present in liver. Alcohol and other toxic compounds that impair liver cells result in a major increase in the activity of this enzyme in serum. Therefore, it is a good marker of injury to the liver and a diagnostic marker for monitoring the abstinence of alcoholic patients during withdrawal therapy. 

In recent studies Aronson s group (see page 220) examined the activities of various enzymes in serum and cerebrospinal fluid and found among other abnormalities a lack of fructose-1-phosphate aldolase in children with TSD. This is a unique finding among the lipidoses and may be useful for detection of hetero-zygotes for the disease (see below). 

The use of enzyme activity assays in the presence and absence of inhibitors has some merit and can be automated. Cholinesterase variants have been detected by Kalow and Genest (1957) and Harris and Whittaker (1961) using dibucaine and fluoride inhibition, respectively they have provided a means of obtaining both qualitative information (type of variant) and quantitative information (activity of cholinesterase in the sample) about the enzyme in serum. 

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