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PubMed1977

The world distribution of the electrophoretic variants of the red cell enzyme esterase D.

The phenotypic variation in the esterase D phenotypes among 2,405 individuals in 14 samples from populations in Europe, Africa and Asia are reported. There exists a marked difference in esterase D allele frequencies in different continental regions. Comparison of the world population data so far available show that esterase D is another useful genetic parameter for the study of population diversity.

Africa↗

PubMed1978

Group-specific component, alpha1-antitrypsin and esterase D in Canadian Eskimos.

Three genetic markers - group-specific component (Gc), alpha1-antitrypsin, and esterase D - were examined in a population of Eskimos from Igloolik in the eastern Canadian Arctic. Gc and esterase D were found to be polymorphic. In addition to the common Gc types, an anodal variant called Gc Igloolik was found, probably identical to previously reported Gc Eskimo. Gene frequencies were Gc1: 0.6524, Gc2: 0.3373, GcIgl: 0.0104, for 338 Eskimos. Genetic types of alpha1-antitrypsin (Pi types) were mostly M, with two MS sibs who were half Caucasian, in 170 Eskimos. Frequencies of the esterase D allele in 336 Eskimos were EsD1: 0.7083, EsD2: 0.2917. The frequencies of Gc2 and EsD2 are both higher than are found in Caucasian populations.

Canada↗

PubMed1982

The pancreolauryl test. A method of assessing the combined functional efficacy of pancreatic esterase and bile salts in vivo?

The pancreolauryl test is marketed as a tubeless test of pancreatic function based on the specific splitting by pancreatic esterase of orally administered fluorescein dilaurate. We have evaluated the test in 50 patients, all of whom had at least one other pancreatic function test (secretin-pancreozymin, Lundh, BT PABA/14C index). The sensitivity of the pancreolauryl test was 75% if equivocal results (T/K 20-30) were excluded and 77% if the equivocal results were included amongst the abnormal results - figures which were similar to those obtained for the other three function tests. However, the specificity of the pancreolauryl test was 60% if equivocal results were excluded, decreasing to only 39% if equivocal results were considered to be abnormal. The false-positive tests chiefly occurred in patients who had previously undergone gastric or biliary by-pass, or vagotomy and cholecystectomy (BT PABA/14C test normal). These data, and the known dependence of esterase activity on bile salts, suggest that the pancreolauryl test assesses the combined functional efficacy of secreted esterase and bile salts. Despite the test's high sensitivity, its low specificity makes it unreliable as a test of pancreatic function per se. The pancreolauryl test may be particularly useful in evaluating patients with bile-pancreatic juice admixture problems.

Bile Acids and Salts↗

PubMed1977

Nonspecific esterase activity in 'hairy cells'.

Nonspecific esterase activity using alpha-naphthyl butyrate as substrate was found to be present in hairy cells from patients with hairy cell leukemia. Activity of this enzyme was markedly diminished and in some instances obliterated by sodium fluoride. Since alpha-naphthyl butyrate is believed to be a more specific substrate for monocytic-type nonspecific esterase than alpha-naphthyl acetate, its presence in hairy cells combined with fluoride inhibition which is also characteristic of monocytic nonspecific esterase provides additional evidence of monocytic properties of hairy cells.

Acetates↗

PubMed1981

A possible explanation of myxedema and hypercholesterolemia in hypothyroidism: control of lysosomal hyaluronidase and cholesterol esterase by thyroid hormones.

Thyroid hormones control the levels of the lysosomal enzymes, cholesterol esterase and hyaluronidase, in rat liver, skeletal muscle and skin. Activities of these enzymes decreased to approximately 40-50% of normal levels in liver cell fractions, skeletal muscle homogenates and skin homogenates from thyroidectomized rats. Treatment of hypophysectomized rats with L-triiodothyronine increased the activities of cholesterol esterase and hyaluronidase approximately 2-fold in liver cell fractions. The low levels of hyaluronidase and cholesterol esterase in thyroidectomized rats may account for the accumulation of mucopolysaccharides in skin and for the elevation of serum cholesterol levels in hypothyroid patients.

Acid Phosphatase↗

PubMed1971

Genetically determined heterogeneity of the C1 esterase inhibitor in patients with hereditary angioneurotic edema.

Normal human serum contains 18 +/-5 mg/100 ml of C1 esterase inhibitor (alpha-2 neuraminoglycoprotein) as estimated by immunochemical means. Of 118 patients with hereditary angioneurotic edema, the sera of 80, from 42 kindred, contained a mean concentration of 3.15 mg/100 ml or 17.5% of normal. The mean serum concentration in 35 patients in 7 other kindred was 20 mg/100 ml or 111% of normal, and 3 patients in another kindred contained over 80 mg/100 ml or greater than 400% of normal. The nonfunctional inhibitors in patients' sera of these eight kindred were identical with normal C1 esterase inhibitor by Ouchterlony analysis, but they were different from normal and from each other with respect to their electrophoretic mobility, their capacity to bind C1 esterase, and their ability to inhibit esterolysis of N-acetyl-tyrosine-ethylester.

Acetates↗

PubMed1976

Assessment of monocyte esterase activity by flow cytophotometry.

An azo dye supravital method has been devised for selectively staining human monocytes in suspension for nonspecific esterase activity. Stained cells can be identified and rapidly enumerated by presenting the suspension of stained cells to the Cytograf, a flow-through cell discriminating cytophotometer. The intensity of stain is proportional to the intracellular esterase activity. By analysis of the oscilloscope display, it has been possible to obtain relative data concerning the degree of activity of monocyte nonspecific esterase activity. These observations suggest a unique approach to the measurement of intracellular enzyme activity in selected cells in a mixed population.

Autoanalysis↗

PubMed1978

Studies on acid lipase, and E 600-resistant acid esterase activities in human tissue homogenates.

Detailed comparison of acid lipase and acid esterase activities of human spleen, liver and kidney homogenates has been carried out by means of the following substrates: 14C-tripalmitin, alpha-naphthyl acetate, alpha-naphthyl butyrate, alpha-naphthyl laurate, p-nitro-phenyl acetate, butyrate and laurate. In addition, homogenates of the three tissues were subjected to isoelectric focusing in polyacrylamide gels and histochemical staining with the above mentioned naphthyl substrates in the presence and absence of the organophosphate esterase inhibitor diethyl-p-nitrophenyl phosphate (E 600). These studies provide extensive support for the proposal that E 600-resistant acid naphthyl butyryl and lauryl esterase activities in human tissues derive largely from the enzyme acid lipase. The studies suggest that the most specific chromogenic substrate for this enzyme at a biochemical and histochemical level is alpha-napthyl laurate in the presence of E600 (3 X 10(-6) M).

Carboxylic Ester Hydrolases↗

PubMed1980

Fluorophosphate-sensitive esterases in mammalian liver: the radioautographic localization and measurement of fluorophosphate-reactive sites in adult rat liver.

Fluorophosphate-reactive (FPR) sites in the adult male rat liver, tentatively identified as esterase active centers, were localized and measured using the combined techniques of quantitative electron microscope radioautography and morphometric analysis with the light and electron microscope. The FPR sites were measured in liver which had been prefixed by perfusion with 1.5% glutaraldehyde and reacted with 10(-4) M tritium-labeled diisopropyl fluorophosphate (3H-DFP). Under the experimental conditions 64-67% of the esterase activity in fresh liver was retained for reaction with the 3H-DFP, which is known to bind irreversibly to the active sites of certain esterases. In light and electron microscope radioautographs the developed silver grains were concentrated over the cytoplasm of hepatocytes. A low concentration occurred over erythrocytes. All other areas in the liver had a concentration of grains resembling the background concentration. Quantitative measurements of grain density in the electron microscope radioautographs revealed the highest density, after correcting for radiation spread, in cytoplasmic granules (mainly cytolysomes). The grain densities over the rough and smooth endoplasmic reticulum and associated structures were also equal to or above the average hepatocyte grain density. Due to the large fractional volume of endoplasmic reticulum per hepatocyte (58% of cell volume) and the fraction of the liver occupied by hepatocytes (79% of liver volume) the majority of FPR sites in the liver occurred in the rough and smooth endoplasmic reticulum and associated structures. The average numbers of FPR sites were calculated per micrometer3 of hepatocyte (5.0 x 10(5) sites/micrometer3) and per unit volume of each significantly labeled organelle. In addition, the number of FPR sites per hepatocyte (2.5 X 10(9) sites/cell), per cm3 liver (4.1 X 10(17) sites/cm3) and in the total liver of an average 100 g male rate (2.2 X 10(18) sites/total liver) were also calculated.

Animals↗

PubMed1996

Classical morphology, esterase cytochemistry, and interphase cytogenetics of peripheral blood and bone marrow smears.

We used peripheral blood (PB) and bone marrow (BM) smears in the development of two methods based on cytomorphology and esterase cytochemistry in combination with fluorescence in situ hybridization (FISH). The first method involves photodocumentation of May-Grünewald-Giemsa (MGG)-stained cells, followed by destaining in methanol-acetic acid, fixation in paraformaldehyde, and digestion with protease and RNAse before FISH using alpha-satellite probes that specify chromosomes X, 7, 8, and 17. On average, two hybridization signals were seen in 94.5% of disomic BM cells. The hybridization sensitivity was found to vary, however, both among morphologically defined hematopoietic cell lineages and among differentation levels within a lineage. In the second method, an esterase staining technique was followed by the same treatment as for MGG-stained cells. The esterases and FISH signals could be simultaneously visualized and the method was found suitable for rapid screening of in situ signals in cytochemically defined granulocytes and lymphocytes but not in monocytes. The combined methods proved very useful in elucidating the clinical significance of chromosomal abnormalities seen in two cases of leukemia.

Blood Cells↗

PubMed2005

Continuous monitoring of cholesterol oleate hydrolysis by hormone-sensitive lipase and other cholesterol esterases.

Hormone-sensitive lipase (HSL) contributes importantly to the hydrolysis of cholesteryl ester in steroidogenic tissues, releasing the cholesterol required for adrenal steroidogenesis. HSL has broad substrate specificity, because it hydrolyzes triacylglycerols (TAGs), diacylglycerols, monoacylglycerols, and cholesteryl esters. In this study, we developed a specific cholesterol esterase assay using cholesterol oleate (CO) dispersed in phosphatidylcholine and gum arabic by sonication. To continuously monitor the hydrolysis of CO by HSL, we used the pH-stat technique. For the sake of comparison, the hydrolysis of CO dispersion was also tested using other cholesteryl ester-hydrolyzing enzymes. The specific activities measured on CO were found to be 18, 100, 27, and 3 micromol/min/mg for HSL, cholesterol esterase from Pseudomonas species, Candida rugosa lipase-3, and cholesterol esterase from bovine pancreas, respectively. The activity of HSL on CO is approximately 4- to 5-fold higher than on long-chain TAGs. In contrast, with all other enzymes tested, the rates of TAG hydrolysis were higher than those of CO hydrolysis. The relatively higher turnover of HSL on CO observed in vitro adds further molecular insight on the physiological importance of HSL in cholesteryl ester catabolism in vivo. Thus, HSL could be considered more as a cholesteryl ester hydrolase than as a TAG lipase.

Cholesterol Esters↗

PubMed1977

Arginine esterase and lysosomal hydrolases in liver from cystic fibrosis subjects.

The total activity and isoelectric focusing patterns of arginine esterase, cathepsin B1, and several lysosomal hydrolases were normal in liver from two patients with cystic fibrosis. No abnormalities were observed in values for pH optimum, Km, and Vmax for arginine esterase and cathepsin B1 in liver from cystic fibrosis patients compared to those values for liver from the control subject. Soybean trypsin inhibitor at concentrations up to 100 microgram/ml had no effect on liver arginine esterase or cathepsin B1.

Adolescent↗

PubMed1978

Decrease of lipase and esterase activities in intestinal contents of newborn infants during test meals.

Both lipase and esterase activities were present in intestinal contents of all newborns studied, from the first day of life. In adults given a test meal lipase activity increased and esterase activity remained unchanged. In contrast, both activities decreased markedly in infants on feeding. During the digestion of the test meal the lipase activity in intestinal contents of the infants was much lower than in adults (ratio of median values 1:27) and the esterase activity was also several fold lower (ratio of median values 1:1.3). Speculation Newborn infants often absorb lipids less efficiently than adults. One contributing factor may be that their incompletely developed pancreas responds to feedings with comparatively low outputs of lipolytic enzymes. The newborn may be more dependent than adults on auxiliary sources of lipase activity such as the pharyngeal lipase and/or the bile-stimulated lipase in human milk.

Adult↗

PubMed1984

Activatable esterase activity of murine natural killer cell--YAC tumour cell conjugates.

Natural killer (NK) cells have been obtained from mouse spleens and grown in vitro. These cells: retained cytotoxicity against YAC targets; and were homogeneous as judged by morphology and surface markers. The alpha-naphthol acetate esterases (ANAE) and diisopropyl-fluorophosphate (DFP)-binding proteins of NK cells, YAC cells and NK-YAC conjugates have been examined. Ultrastructural cytochemistry indicates that NK cells have two types of ANAE: an enzyme primarily associated with the granule externum and an activatable ANAE associated with the granule internum. Both of these activities are inhibited by DFP. The activatable ANAE appears during incubation of NK cells with YAC cells. DFP-binding proteins were examined by sodium dodecyl sulphate/polyacrylamide gel electrophoresis and autofluorography. NK cells and YAC cells have major DFP-binding proteins of 35 X 10(3) and 20 X 10(3) Mr, respectively. NK-YAC conjugates had a new band at 55 X 10(3) Mr. This new protein may be identical to the activatable ANAE described above. Our studies provide evidence for an NK cell esterase that becomes activated when incubated in the presence of tumour cells. This esterase may be related to the cytolytic mechanism.

Animals↗

PubMed1995

Partial purification and characterization of an esterase acting on the anticancer pro-drugs, 7-ethylcamptothecin derivatives.

A hydrolytic enzyme which catalyzes hydrolysis of the ester-linkage of a series of 17-O-acyl derivatives of 7-ethylcamptothecin-21-(2-dimethylamino)ethylamide [acyl derivatives of 22E] was purified from rat liver and its properties were characterized. It hydrolyzed the ester-linkage of all 22E derivatives tested as well as p-nitrophenyl acetate at pH 8-9 but had no effect on 7-ethyl-10-[4-(piperidino)-1-piperidino] carbonyloxycamptothecin (CPT-11: irinotecan), unlike CPT-11 converting carboxylesterase, which was previously purified from rat serum [Tsuji T. et al., J. Pharmacobio-Dyn., 14, 341 (1991)]. The enzyme had no effect on either acetyl choline or butyrylcholine. It was inhibited by several organophosphorous compounds such as diisopropyl fluorophosphate (DFP), bis-(p-nitrophenyl)phosphate and paraoxon, but was insensitive to inhibitors specific for choline esterases. These results indicate that this liver esterase is clearly distinct from choline esterase and serum CPT-11 converting enzyme and is able to convert pro-drugs, O-acyl derivatives of 22E, to an antitumor agent.

Animals↗

PubMed2003

Age dependency of esterase activity in rat and human keratinocytes.

The age and species dependent characteristics of cutaneous esterase activity were examined in cultured keratinocytes of neonatal and adult humans and of rats at the age of 1, 3, 10, and 50 d. The existence of esterases was characterized using fluorescein-5-isothiocyanate diacetate under a confocal laser scanning microscope. In vitro hydrolysis of ethyl nicotinate (EN), an esterified prodrug of nicotinic acid, was investigated in homogenate of cultured keratinocytes, and the Michaelis-Menten parameters (V(max) and K(m)) of EN were evaluated. Together with development and growth of rats and humans, V(max) and V(max)/K(m) increased drastically, suggesting that esterases in keratinocytes develop markedly during the growth process. The affinity parameter, K(m), was almost the same among the ages in each species. These findings in cultured keratinocytes corresponded with our previous report using dissected skin specimens. Species differences in V(max), V(max)/K(m) and K(m) were also observed, and these parameters of EN hydrolysis in rats were significantly higher than that in humans. In conclusion, cultured keratinocytes can be an advantageous method with which to estimate cutaneous activation of ester prodrugs in humans and during the growth process.

Aging↗

PubMed1984

Alloantibody to a sex-influenced esterase in rats (Rattus norvegicus).

An antiserum to a serum protein from female ACI rats was produced in DONRYU rats by alloimmunization. The serum protein reacting with this antiserum was shown to be a sex-influenced esterase which is identified by zymogram techniques. Evidence for this is as follows: this protein migrated in the albumin region on agarose gel immunoelectrophoresis and was not present in sera from mature males; all rats possessing the protein were sex-influenced esterase in sera specifically disappeared after treatment with this antiserum. The attempt in ACI rats to produce antiserum to the esterases from DONRYU rats was unsuccessful.

Animals↗

PubMed1990

Distorted segregation of the esterase isozyme genotypes in barley (Hordeum vulgare L.).

Distorted segregation of the esterase isozyme genotypes was observed in F2 population which was produced from a cross combination between 'Ko A' and 'Mokusekko 3' of barley varieties. After examining the segregation of esterase isozyme genotypes in B1F1 hybrids derived from the reciprocal backcrosses, it was made clear that the distorted segregation was caused by certation between pollens of different genotypes, independent of the female genotypes. Furthermore, the certation was controlled by a newly designated gene, Ga2, at the locus which was linked with the multiocus, Est1, Est2 and Est4, for esterase isozymes at the long arm of chromosome 3. The distorted segregation ratios did not significantly vary among F2 populations derived from F1 hybrids of the same combination which were grown in different years. Mechanically mixed pollens of the parents, however, could not induce the certation.

Chimera↗