对乙酰氨基酚在家蚕体内的糖基化代谢特点和对组织的损伤作用

Glycosylation Metabolic Characteristics of Acetaminophen in Bombyx mori and Damage to Larval Tissues

以临床解热镇痛药基本成分对乙酰氨基酚(APAP)为模药,调查APAP在家蚕体内的代谢和对蚕体主要组织(系统)的损伤以及蚕体主要解毒酶基因的表达变化,探讨家蚕作为肝毒性药物毒理研究替代实验动物的可能性。家蚕5龄2 d幼虫经口给予APAP后0.5 h,在消化管、脂肪体和血淋巴中均能够检测到原药,APAP主要糖基化解毒代谢途径中的关键酶——尿苷二磷酸-葡萄糖醛酸基转移酶(UGT)活性也随即快速上升,其中脂肪体中的UGT酶活性上升早于血淋巴和消化管。实时荧光定量PCR(qRT-PCR)分析显示,幼虫消化管和脂肪体细胞中UGT家族基因Ugt30、Ugt86和Ugt89的转录水平在给予APAP后0.5 h开始显著上调。HE染色显示,高剂量APAP对蚕体消化管和脂肪体组织具有损伤作用,但AO/PI染色未发现血淋巴中死细胞增多。研究结果表明,家蚕的消化管、脂肪体和血淋巴都有通过糖基化代谢APAP的解毒功能,过量的APAP对消化管和脂肪体组织都有损伤作用。

Taking the basic component acetaminophen（ APAP） in clinical antipyretic analgesics as the model drug,we investigated the metabolism of APAP in silkworm（ Bombyx mori） and its damage to major tissues（ systems） of silkworm larvae,and the expression variation of main detoxification enzyme genes to discuss the possibility of using silkworm as the substituted experimental animal in the study of hepatotoxic drugs＇ toxicology. At 0. 5 h after oral administration to day2 silkworm larvae of the 5th instar,APAP was tracked in digestive tract, fat body and hemolymph in silkworm.Thereupon,the activity of UDP-glucuronosyltransferases（ UGT）,which are the key enzymes in main metabolic pathway of glycosylation detoxification of APAP,also increased quickly,and the enzymatic activity in fat body increased earlier than those in hemolymph and digestive tract. The results of real-time fluorescent quantitative（ qRT-PCR） analysis showed that at 0. 5 h after oral administration,the transcription level of UGT family genesUgt30,Ugt86 and Ugt89 significantly increased in fat body and digestive tract cells. HE staining showed that high dose of APAP can lead to damage of digestive tract and fat body,while the number of dead haemocytes was not found increased in circulative hemolymph by AO/PI staining. The results showed that the digestive tract,fat body and hemolymph of silkworm all have APAP detoxification function through glycosylation metabolization,while the excessive APAP could lead to injuring of digestive tract and fat body tissues in silkworm.