不同动物物种中的犬尿氨酸途径酶。

Kynurenine pathway enzymes in different species of animals.

作者信息

Allegri Graziella, Bertazzo Antonella, Biasiolo Monica, Costa Carlo V L, Ragazzi Eugenio

机构信息

Department of Pharmaceutical Sciences, University of Padova, Via Marzolo 5, I-35131 Padova, Italy.

出版信息

Adv Exp Med Biol. 2003;527:455-63. doi: 10.1007/978-1-4615-0135-0_53.

DOI:10.1007/978-1-4615-0135-0_53

PMID:15206763

Abstract

Kynurenine pathway enzyme activities, liver tryptophan 2,3-dioxygenase (TDO), small intestine indole 2,3-dioxygenase (IDO), liver and kidney kynurenine 3-monooxygenase, kynurenine-oxoglutarate transaminase, kynureninase, 3-hydroxyanthranilate 3,4-dioxygenase and aminocarboxymuconate-semialdehyde decarboxylase, were assayed in rabbits, rats, mice and guinea pigs. Their activities varied among species. Especially, TDO was present as both holoenzyme and apoenzyme only in rat, while the other species, rabbit, mouse and guinea pig, only showed holoenzyme activity. Mitochondrial liver and kidney kynurenine 3-monooxygenase activities were much higher in mouse and rat, with rabbit showing the lowest activity. Kynureninase activity showed similar values in both liver and kidney in each species. However, lower activity was present in rabbit. As regards kynurenine-oxoglutarate transaminase, the highest activity appeared in kidney, in all species studied. 3-Hydroxyanthranilate 3,4-dioxygenase activity showed different behaviour in the four species. In rabbit, its activity was higher in kidney than in liver; in rat and mouse, it was viceversa; and in guinea pig, both liver and kidney had similar activity. Instead, the activity of aminocarboxymuconate-semialdehyde decarboxylase was higher in kidney than in liver only in guinea pig. Serum tryptophan concentrations were also determined. Rabbit and guinea pig showed similar values, whereas in rat and mouse, serum tryptophan levels were higher, rat having the highest concentrations. In all species assayed, the free fraction was present as 11-12% of total tryptophan.

摘要

在兔、大鼠、小鼠和豚鼠中测定了犬尿氨酸途径的酶活性，包括肝脏色氨酸2,3-双加氧酶（TDO）、小肠吲哚2,3-双加氧酶（IDO）、肝脏和肾脏犬尿氨酸3-单加氧酶、犬尿氨酸-酮戊二酸转氨酶、犬尿氨酸酶、3-羟基邻氨基苯甲酸3,4-双加氧酶和氨基羧基粘康酸半醛脱羧酶。它们的活性在不同物种间有所差异。特别是，TDO仅在大鼠中同时以全酶和脱辅基酶的形式存在，而其他物种，兔、小鼠和豚鼠，仅表现出全酶活性。小鼠和大鼠肝脏和肾脏线粒体中的犬尿氨酸3-单加氧酶活性要高得多，兔的活性最低。每个物种肝脏和肾脏中的犬尿氨酸酶活性值相似。然而，兔中的活性较低。至于犬尿氨酸-酮戊二酸转氨酶，在所研究的所有物种中，肾脏中的活性最高。3-羟基邻氨基苯甲酸3,4-双加氧酶活性在这四个物种中表现不同。在兔中，其在肾脏中的活性高于肝脏；在大鼠和小鼠中则相反；在豚鼠中，肝脏和肾脏的活性相似。相反，氨基羧基粘康酸半醛脱羧酶的活性仅在豚鼠的肾脏中高于肝脏。还测定了血清色氨酸浓度。兔和豚鼠的值相似，而大鼠和小鼠的血清色氨酸水平较高，大鼠的浓度最高。在所有测定的物种中，游离部分占总色氨酸的11-12%。