仓鼠肺中磷脂酶A2的特性以及博来霉素对该酶的体内外作用

Characterization of a phospholipase A2 in hamster lung and in vitro and in vivo effects of bleomycin on this enzyme.

作者信息

Wang Q, Giri S N, Hyde D M

机构信息

Department of Veterinary Pharmacology and Toxicology, School of Veterinary Medicine, University of California, Davis 95616.

出版信息

Prostaglandins Leukot Essent Fatty Acids. 1989 May;36(2):85-92. doi: 10.1016/0952-3278(89)90023-9.

DOI:10.1016/0952-3278(89)90023-9

PMID:2474835

Abstract

Phospholipase A2 (PLA2) activity from adult hamster lung was characterized using L-alpha-1-palmitoyl-2-arachidonyl-[arachidonyl-1-14C]-phosphatidylcholine as the substrate. The released [14C]-arachidonic acid was separated by TLC. The enzyme activity increased with increasing incubation time (0-120 minutes), calcium ion concentration (0-25.0 mM) and protein (0-2.0 mg). The optimum pH was 8.0. Deoxycholate had a concentration dependent (0.1 to 0.5 mM) inhibitory effect on the activity. PLA2 specific activity was the highest in mitochondrial fraction. PLA2 activity following incubation with bleomycin was increased in a dose related fashion. In vivo study showed that both PLA2 activity and collagen content in hamster lung were significantly elevated at 14 days followed intratracheal instillation of bleomycin. The activation of PLA2 may play an important role in bleomycin-induced pulmonary toxicity.

摘要

使用L-α-1-棕榈酰-2-花生四烯酰-[花生四烯酰-1-¹⁴C]-磷脂酰胆碱作为底物，对成年仓鼠肺中的磷脂酶A2（PLA2）活性进行了表征。通过薄层层析法分离释放出的[¹⁴C]-花生四烯酸。酶活性随孵育时间（0 - 120分钟）、钙离子浓度（0 - 25.0 mM）和蛋白质（0 - 2.0 mg）的增加而增加。最适pH为8.0。脱氧胆酸盐对活性有浓度依赖性（0.1至0.5 mM）抑制作用。PLA2比活性在线粒体部分中最高。与博来霉素孵育后的PLA2活性呈剂量相关增加。体内研究表明，气管内注入博来霉素后14天，仓鼠肺中的PLA2活性和胶原蛋白含量均显著升高。PLA2的激活可能在博来霉素诱导的肺毒性中起重要作用。