犊牛体内丙草胺、萘和敌草腈代谢过程中不存在半胱氨酸S-共轭N-乙酰转移酶活性的证据。

Evidence for the absence of cysteine S-conjugate N-acetyltransferase activity in the metabolism of propachlor, naphthalene, and dichlobanil in calves.

Bakke J E, Davison K L, Larsen G L

Metabolism and Radiation Research Laboratory, Agricultural Research Service, US Department of Agriculture, Fargo, ND 58105.

Xenobiotica. 1990 Aug;20(8):801-7. doi: 10.3109/00498259009046894.

Abstract

The glutathione conjugate of 2-chloro-N-isopropyl[1-14C]acetanilide (14C-propachlor) was perfused through a calf kidney in situ; 23% of the dose was excreted in the perfused kidney urine as the cysteine conjugate, no mercapturic acid was detected. 2. A 5-day-old calf dosed orally with 14C-propachlor excreted 70% dose in the urine as the cysteine conjugate; no mercapturic acid was detected. Rumen microflora were established in the calf (5 weeks older) and the experiment was repeated with the same results. 3. When the same calf was dosed 1 week later with 14C-naphthalene, 99% dose was excreted in the urine, mostly as the dihydrodiol-glucuronide (34%) and the dihydrohydroxy-cysteine conjugate (47%); no mercapturate was detected. 4. A 9-day-old calf dosed orally with 2,6,-dichlorobenzo[14C]nitrile (14C-dichlobanil) excreted 67% dose in the urine as cysteine conjugates (34%), and products of cysteine conjugate beta-lyase cleavage of cysteine conjugates (30%); no mercapturates were detected. 5. Cysteine S-conjugate N-acetyltransferase activity in calf kidney and liver was about 10% of that in the corresponding rat tissues.

摘要

将2-氯-N-异丙基[1-¹⁴C]乙酰苯胺（¹⁴C-毒草安）的谷胱甘肽共轭物原位灌注到小牛肾脏中；23%的剂量以半胱氨酸共轭物的形式随灌注肾脏尿液排出，未检测到巯基尿酸。2. 给一只5日龄的小牛口服¹⁴C-毒草安，70%的剂量以半胱氨酸共轭物的形式随尿液排出；未检测到巯基尿酸。在小牛（5周龄更大）中建立瘤胃微生物区系，并重复该实验，结果相同。3. 1周后给同一只小牛投喂¹⁴C-萘，99%的剂量随尿液排出，大部分为二氢二醇-葡萄糖醛酸苷（34%）和二氢羟基-半胱氨酸共轭物（47%）；未检测到巯基尿酸盐。4. 给一只9日龄的小牛口服2,6-二氯苯[¹⁴C]腈（¹⁴C-敌草腈），67%的剂量随尿液排出，其中半胱氨酸共轭物占34%，半胱氨酸共轭物的β-裂解酶裂解产物占30%；未检测到巯基尿酸盐。5. 小牛肾脏和肝脏中的半胱氨酸S-共轭物N-乙酰转移酶活性约为相应大鼠组织的10%。