Gene Mapping and Linkage Homology

Zutphen, L.F.M. van; Bieman, M. G. C. W. den

doi:10.1007/978-94-009-3281-4_32

Cited by 8 publications

(2 citation statements)

References 16 publications

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“…The esterases cleave aliphatic esters of short‐chain carboxyl acids, aromatic esters, aromatic amides, phosphoesters, and thioesters. The physiological function of many esterases is still obscure, but they probably are essential because their genetic codes have been preserved throughout evolution (Van Zutphen et al, ; Urich, ). Several studies have suggested that human serum esterases are involved in metabolizing various classes of lipids, such as mono‐ and triacylglycerols (Tsujita and Okuda, ; Shirai et al, ).…”

Section: Commentarymentioning

confidence: 99%

Assays for the Classification of Two Types of Esterases: Carboxylic Ester Hydrolases and Phosphoric Triester Hydrolases

Anspaugh

Roe

2002

CP Toxicology

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Assays for the Classification of Two Types of Esterases: Carboxylic Ester Hydrolase and Phosphoric Triester Hydrolase (Douglas D. Anspaugh and Michael Roe, North Carolina State University, Raleigh, North Carolina). This unit describes assays that quantitate two types of esterase the carboxylic ester hydrolases and the phosphoric triester hydrolases. Carboxylic ester hydrolases include the B-esterases, which are inhibited by organophosphorus compounds. Among the phosphoric triester hydrolases is aryldialkylphosphatase, which has been called A-esterase or paraoxonase due to its ability to oxidize paraoxon and other organophosphates. These assays are colorimetric and miniaturized for rapid simultaneous testing of multiple, small-volume samples in a microtiter plate format. There is also a discussion of the history of esterase nomenclature and the reasons why this large group of enzymes is so difficult to classify.

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Section: Commentarymentioning

confidence: 99%

Assays for the Classification of Two Types of Esterases: Carboxylic Ester Hydrolases and Phosphoric Triester Hydrolases

Anspaugh

Roe

2002

CP Toxicology

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“…Wassmer et al (1988) described that an increased activity of lymph ES-2 was seen in mice after infusion of fat into the duodenum. Mouse esterase isozyme ES-2 is assumed to be homologous with rat ES-1 (Augustinsson & Henricson, 1966;Van Zutphen & Den Bieman, 1988). Wassmer et al.…”

Section: Discussionmentioning

confidence: 99%

Influence of amount of dietary fat and protein on esterase-1 (ES-1) activities of plasma and small intestine in rats

et al. 1992

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The objective of the present study was to characterize nutritionally esterase-1 (ES-1). For this purpose, the effects of replacement of dietary carbohydrates by isoenergetic amounts of either fat or protein on ES-1 activities of plasma and small intestine were studied in male rats. Purified diets differing in the amounts of maize starch plus dextrose, casein and various types of fat were used. Plasma and jejunal ES-1 activities were found to be increased with increasing fat intakes. As to the type of fat, increasing plasma ES-1 activities were induced by coconut fat, olive oil, maize oil and medium-chain triacylglycerols, in this order. Maize oil induced higher jejunal ES-1 activities than coconut fat and olive oil, but had similar effects to medium-chain triacylglycerols. Maize oil was more powerful in increasing plasma ES-1 activity than isoenergetic amounts of casein, but with respect to jejunal ES-1 activity these dietary components were equally effective. It is concluded that the amounts of fat and protein in the diet are important determinants of ES-I activities in plasma and jejunum.Dietary fat: Esterase-I: Plasma: Intestine: Rat Esterases (EC 3.1.1 .) form a complex system of non-specific enzymes present in most living organisms (Krisch, 1971). They can be detected in most tissues, but are most abundant in liver, intestine, kidney and plasma. The esterases catalyse the hydrolysis of artificial organic esters such as a-naphthylacetate and p-nitrophenylacetate. Isozymes of esterase catalyse the hydrolysis of a wide range of xenobiotic carboxylesters and aromatic amides, including various anaesthetics (Mentlein & Heymann, 1984).The function of the esterases with respect to natural substrates is still obscure, but there is some evidence that they are involved in lipid metabolism. In vitro studies have shown that rat liver esterases can hydrolyse various classes of lipids, including monoacylglycerols (Mentlein et al. 1985). Involvement of esterases in lipid metabolism is also indicated by in vivo studies. Replacement of isoenergetic amounts of carbohydrates by either maize oil or coconut fat in the diet of rats caused a slight increase in plasma total esterase activity, as measured with p-nitrophenylacetate as substrate (Van Lith et al. 1989). This increase was associated with a pronounced increase of the so-called ES-1 isozyme, an anodal, fastmoving esterase zone in the plasma zymogram. Lewis & Hunter (1966) reported that administration of fat by stomach tube caused an increase in the activity of esterase of high electrophoretic mobility in intestinal lymph of rats. It could be suggested that ES-1 is involved in fat absorption and that it is released from the intestine during this process. Three dietary trials with rats have been carried out in order to obtain clues as to this H. A. V A N L I T H A N D O T H E R Ssuggestion and to characterize plasma and jejunal ES-1 activities nutritionally. The amount and type of fat and the amount of protein in the diet have been focussed on as possible determinants of ...

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