Serum Alkaline Phosphatase Isoenzymes Research Articles

A simplified heat-inactivation method for investigating alkaline phosphatase isoenzymes in serum

A method is described for the determination of the percentage of liver alkaline phosphatase in serum samples in which measurements of residual activity are made after incubating the samples for 15 and 25 min at 56° C. This method has the advantage of taking into account quantitative variations in the heat stability characteristics of liver alkaline phosphatase from one sample to another, in contrast to methods in which only a single period of exposure to 56° C is employed.

Chemical Inhibition Method for Alkaline Phosphatase Isoenzymes in Human Serum

The authors adapted a chemical inhibition procedure using L-phenylalanine and urea as specific inhibitors to quantitate the activities of bone, liver, and intestinal alkaline phosphatase (ALP) isoenzymes in human serum. The results of this assay were compared with electrophoretic separation, gamma-glutamyl transpeptidase (GGTP) activity, and the clinical setting in a group of patients with elevated total ALP activity. In addition, expected ranges of serum ALP isoenzymes for healthy young men and also for a geriatric population are presented.

Analysis of heat inactivation curves of alkaline phosphatase isoenzymes in serum

The course of the decline in alkaline phosphatase activity during exposure of serum samples to a temperature of 56°C can be resolved into two phases. These represent the exponential decay of an enzyme component with an average half-inactivation time of 112 seconds and of a second component with an average half-inactivation time of 456 seconds. The more rapid fall is due to inactivation of bone alkaline phosphatase and the slower to inactivation of liver and, when present, intestinal phosphatases. The half-inactivation times of the different enzyme species show considerable variation from one serum sample to another. The implications of this variation for methods of estimating the relative proportions of alkaline phosphatase isoenzymes by selective inactivation procedures are discussed.

Serum and Placental lactic dehydrogenase and alkaline phosphatase isoenzymes in normal pregnancy and in pre-eclampsia.

LDH isoenzymes and heat-stable alkaline phosphatase were studied in the serum and placental extract of 20 cases of pre-eclampsia and 10 normal pregnancies as a control. The starch-gel electrophoretic serum and placental isoenzymogram showed that LDH4 and LDH5 were the main isoenzymes in the placenta while LDH1 and LDH2 were the main isoenzymes in the serum in pre-eclampsia. The electrophoretic serum protein pattern in pre-eclamlobulins with decreased albumin fraction, while in the placenta, the albumin fraction was increased together with a decrease in the alpha-globulins. The electrophoretic pattern of serum alkaline phosphatase showed a main band of activity at the B-globulin zone in all cases of normal pregnancy and pre-eclampsia. In the placenta, two additional bands were detected.

Clinical value of serum alkaline phosphatase isoenzyme estimations in the elderly.

The value of the estimation of liver and bone isoenzyme of alkaline phosphatase in a series of 500 admissions to a geriatric unit is described. A raised total alkaline phosphatase was found in 40 patients and this was due to raised levels of the bone isoenzyme in about two-thirds of these. Its value in diagnosis of treatable bone disease is emphasized.

Quantitative analysis of serum alkaline phosphatase isoenzyme activity

Quantitative analysis of serum alkaline phosphatase isoenzyme activity

The nature of the serum alkaline phosphatases in liver diseases.

The two main alkaline phosphatase isoenzymes in serum from patients with extrahepatic biliary obstruction have been purified. Properties of these isoenzymes, such as electrophoretic mobility, separation on gel filtration, ultracentrifugation characteristics, Michaelis constants, and sensitivity to neuraminidase have been studied and compared with the isoenzymes of liver and bile. The results show that there is an abnormal isoenzyme in the serum from these patients and that this isoenzyme is similar but not identical with the main bile isoenzyme. It is suggested that it may be associated with a lipoprotein carrier.

Characterization of alkaline phosphatase isoenzymes in serum by agar gel electrophoresis

A simple method of characterizing alkaline phosphatase isoenzymes in serum by agar gel electrophoresis is described. By using sera from cases of obstructive jaundice as markers in the electrophoresis reproducible β 2-phosphatase could be obtained. Combining the electrophoretic tests with heat stability tests at 56° bile, liver, bone, intestinal, and placental isoenzymes could be assessed for routine clinical purposes. Results obtained with 221 normal subjects are given and the clinical use of the method is briefly discussed.

A relative heat stability test for the identification of serum alkaline phosphatase isoenzymes

A new approach is presented for the identification of increased levels of serum alkaline phosphatase isoenzyme activity by heat inactivation. The pattern of enzyme stability at 56° over a 20-min period is compared with simultaneously determined patterns for control sera from patients with diagnosed liver and bone disease. This assessment of relative heat stability patterns has allowed the differentiation between liver and bone as the tissue source of increased serum alkaline phosphatase in 93% of the cases.

Profiles of alkaline phosphatase isoenzymes in serum using cellulose acetate electrophoresis and organ-specific inhibitors.

Profiles of isoenzymes of alkaline phosphatase in the serum using a substrate-gel imprint following electrophoresis on cellulose acetate, organ-specific inhibitors (urea and L-phenylalanine), and heat inactivation are presented. The behavior of the frequently encountered mixtures of isoenzymes is emphasized. The isoenzyme couplet seen in hepatobiliary disorders is studied in relation to magnitude of total alkaline phosphatase, ABO blood group, and serum bilirubin levels. The alkaline phosphatase electrophoretic patterns seen in the sera of 43 normal pregnant women at term are classified according to the amount of placental alkaline phosphatase present and are related to age, blood group, and multiparity.

Observations on the heat-stability of alkaline phosphatase isoenzymes in serum

Serum specimens which apparently contain the same isoenzyme of alkaline phosphatase nevertheless show wide variations in the stabilities of their phosphatase activities on heating at 56°. A number of factors which may influence the stability of bone and liver phosphatases in serum have been studied and their contributions to the observed variability of serum phosphatase heat-stabilities have been assessed. Differences between specimens in protein or urea content do not appear to be significant in this respect, but differences in pH may cause variability in enzyme heat-stability. When differences between serum samples in characteristics such as pH have been taken into account, however, the range of variation which still remains suggests that a particular phosphatase isoenzyme entering the circulation in different individuals and in various diseases may not have constant stability properties.

Serum alkaline phosphatase isoenzyme patterns in disease

Serum alkaline phosphatase isoenzyme patterns have been obtained using starch gel electrophoresis. The intestinal isoenzyme was detected in about one-third of over 300 serum samples examined. The incidence was high in cirrhosis and chronic renal failure but low in gastrointestinal disease. In serum from some patients the intestinal isoenzyme was the only isoenzyme present. Isoenzymes of unusual electrophoretic mobility were found in the serum of eight patients.

Cellulose Acetate Electrophoresis of Alkaline Phosphatase Isoenzymes in Human Serum and Tissue

Abstract We describe a new electrophoretic method for the characterization of human serum and tissue alkaline phosphatases on cellulose acetate plates. Enzymes are localized fluorometrically with the substrate α-naphthol AS-MX phosphate or colorimetrically by coupling the reaction product with Fast Blue RR. Both localization techniques are sensitive enough to demonstrate isoenzyme patterns in micro-scale samples of normal sera. Our electrophoretic studies indicate that sera of children and adults normally contain isoenzymes originating from both liver and bone. The high sensitivity of the method allows the use of normal sera as markers rather than tissue extracts, and isoenzyme patterns may be visually assessed after heat inactivation and chemical inhibition. The method is suitable for the electrophoretic fractionation of alkaline phosphatase in large numbers of sera, with equipment and technique familiar to many laboratories.

A Study of Various Electrophoretic and Inhibition Techniques for Separating Serum Alkaline Phosphatase Isoenzymes

Abstract Optimal conditions for the identification and semiquantitation of the isoenzymes of serum alkaline phosphatase are reviewed and a new technique is presented. In the recommended scheme, specific disc electrophoretic conditions are used to produce good separations, which are improved by comparing the alkaline phosphatase patterns of sera before and after treatment with heat or urea (3 mol/liter). This method is compared with other electrophoretic and inhibition techniques. Interpretation is aided by (a) reference to the relative mobilities of each isozyme, and (b) inactivation of bone alkaline phosphatase by heat or urea. The isozymes originating from bile, intestine, placenta, bone, and liver can be independently resolved as separate bands with untreated sera except when bone alkaline phosphatase is grossly increased. The proposed method permits identification and semiquantitation of all the recognized alkaline phosphatase isozymes in most sera, as an aid to diagnosis.

Normal serum alkaline phosphatase isoenzymes examined by acrylamide and starch gel electrophoresis and by isoenzyme analysis using organ-specific inhibitors.

The serum alkaline phosphatase isoenzymes of 56 normal individuals have been studied from three points of view: the partition of intestinal type alkaline phosphatase from nonintestinal by L-phenylalanine inhibition and their respective heat sensitivities; the performance of starch gel electrophoresis; and acrylamide gel electrophoresis of all sera. The improved acrylamide gel electrophoresis technic did separate bone and liver isoenzymes more effectively than starch gel electrophoresis. The liver position of every subject was seen as the fastest moving compact band and had relatively low heat inactivation, whereas the bone band was slower, less compact, and had a high heat inactivation. The intestinal position was easily observed on starch gel electrophoresis, and was visualized on acrylamide gel by the subsequent use of the liver and bone inhibitor, L-homoarginine, in the substrate medium. These results show the heterogeneity of alkaline phosphatase isoenzymes in the serum of the normal individual.

Detection of Isoenzymes of Chicken Serum Alkaline Phosphatase Using Polyacrylamide Disc Electrophoresis

STARCH, agar, and polyacrylamide gels have been used in the separation of chicken serum and plasma alkaline phosphatase. Phosphatase zymograms using starch gel consisted of a single isoenzyme (Law and Munroe, 1965; Wilcox, 1966; Grunder et al., 1969). Tamaki and Tanabe (1970) compared starch, agar and polyacrylamide gel separations of plasma alkaline phosphatase. Starch and agar gel zymograms contained either 1 or 2 isoenzymes. Polyacrylamide gel zymograms contained two isoenzymes. Zymograms from starch-gel electrophoretic separations of individual chicken and Japanese quail sera each contained a single phosphatase isoenzyme (Savage, 1970). In contrast, the examination of over 700 quail sera in our laboratory, using polyacrylamide disc gel electrophoresis has shown that each serum sample contained at least two alkaline phosphatase isoenzymes and some samples as many as 4 (Savage et al., 1970a). The purpose of this report is to demonstrate additional isoenzymes of chicken serum alkaline phosphatase which have been detected…

Onset of Egg Production and its Relationship to Isoenzymes of Serum Alkaline Phosphatase in Japanese Quail

ELECTROPHORETIC separations of avian serum proteins have shown that some components are influenced by sex, age, and physiology. Kristjansson et al. (1963) demonstrated in chickens that the serum protein prealbumin B was present in laying females, but not in non-laying females, males or immature chickens. Qualitative and quantitative changes of 5 distinct serum protein components observed in the domestic fowl have been related to the onset and termination of egg production in females (Lush, 1963). Hashiguchi et al. (1968) found no sex-associated serum protein pattern in young Japanese quail or in adult males, but a new protein band designated as J was present in laying females.A change in the zymogram of serum alkaline phosphatase specifically associated with the onset of egg production in female Japanese quail is described in this report.MATERIALS AND METHODSThe Japanese quail (Coturnix coturnix japonica) used in this research were derived from a population…

Diagnostic use of serum alkaline phosphatase isoenzymes and 5-nucleotidase

1. 1. Serum 5-nucleotidase and alkaline phosphatase isoenzymes separated on polyacrylamide gel have been examined in 114 patients with raised total alkaline phosphatase. 2. 2. The isoenzymes gave a good indication of clinical diagnosis of liver and bone disease, with 20% showing multiple bands of more than one origin. 3. 3. 5-Nucleotidase was raised in most but not all patients with hepatobiliary disorders. It is therefore a reasonably specific test of liver disease, but as it is not very sensitive, a normal 5-nucleotidase (with raised alkaline phosphatase) does not exclude this diagnosis, and does not necessarily indicate bone as the origin of the raised alkaline phosphatase. 4. 4. Polyacrylamide gel electrophoresis of alkaline phosphatase isoenzymes is of particular value in cases where there is some difficulty in clinical diagnosis, or where the alkaline phosphatase is high with otherwise normal liver function tests and 5-nucleotidase.

Serum alkaline phosphatase isoenzymes: An aid to the diagnosis of liver diseases

Serum alkaline phosphatase isoenzymes: An aid to the diagnosis of liver diseases

Studies on serum alkaline phosphatase isoenzyme (II) Effects of various inhibitors on it

Studies on serum alkaline phosphatase isoenzyme (II) Effects of various inhibitors on it