猪蛔虫中γ-谷氨酰转肽酶的活性

gamma-Glutamyl transpeptidase activity in Ascaris suum.

作者信息

Dass P D, Donahue M J

出版信息

Mol Biochem Parasitol. 1986 Sep;20(3):233-6. doi: 10.1016/0166-6851(86)90103-9.

Abstract

Using histochemical techniques gamma-glutamyl transpeptidase activity has been localized mainly in the cuticle-hypodermis in Ascaris suum. The specific activity of gamma-glutamyl transpeptidase was 3.87 +/- 0.49 mumol h-1 (g tissue)-1 in cuticle-hypodermis as compared to gastrointestinal tract, where it was 0.07 +/- 0.02 mumol h-1 (g tissue)-1, and muscle and reproductive tract where it was less than 0.001 mumol h-1 (g tissue)-1. When cuticle sections were incubated with labelled glutamine a large portion of the glutamine nitrogen was recovered as ammonia which indicated glutamine uptake and utilization by the cuticle-hypodermis. Collectively these histochemical and biochemical data support the fact that gamma-glutamyl transpeptidase activity is found in the cuticle-hypodermis of A. suum and this may be an indication that amino acid absorption could occur through the cuticle via the gamma-glutamyl cycle.

摘要

利用组织化学技术，γ-谷氨酰转肽酶活性主要定位于猪蛔虫的角质层-皮下组织。与胃肠道相比，角质层-皮下组织中γ-谷氨酰转肽酶的比活性为3.87±0.49 μmol h⁻¹（g组织）⁻¹，胃肠道中为0.07±0.02 μmol h⁻¹（g组织）⁻¹，肌肉和生殖道中则小于0.001 μmol h⁻¹（g组织）⁻¹。当角质层切片与标记的谷氨酰胺一起孵育时，大部分谷氨酰胺氮以氨的形式回收，这表明角质层-皮下组织摄取并利用了谷氨酰胺。这些组织化学和生物化学数据共同支持了这样一个事实，即γ-谷氨酰转肽酶活性存在于猪蛔虫的角质层-皮下组织中，这可能表明氨基酸可以通过γ-谷氨酰循环经角质层吸收。