Stegelmeier B L, James L F, Panter K E, Ralphs M H, Gardner D R, Molyneux R J, Pfister J A
USDA/ARS Poisonous Plant Research Laboratory, Logan, Utah 84341, USA.
J Nat Toxins. 1999 Feb;8(1):35-45.
Locoweed poisoning is a chronic disease that develops in livestock grazing for several weeks on certain Astragalus and Oxytropis spp. that contain the locoweed toxin, swainsonine. The purpose of this review is to present recent research on swainsonine toxicokinetics and locoweed-induced clinical and histologic lesions. Swainsonine inhibits cellular mannosidases resulting in lysosomal storage disease similar to genetic mannosidosis. Diagnosis of clinical poisoning is generally made by documenting exposure, identifying the neurologic signs, and analyzing serum for alpha-mannosidase activity and swainsonine. All tissues of poisoned animals contained swainsonine, and the clearance rates from most tissues was about 20 hours (T1/2 half life). The liver and kidney had longer rate of about 60 hours (T1/2). This suggests that poisoned animals should be allowed a 28-day withdrawal to insure complete swainsonine clearance. Poisoning results in vacuolation of most tissues that is most obvious in neurons and epithelial cells. Most of these histologic lesions resolved shortly after poisoning is discontinued; however, some neurologic changes are irreversible and permanent.
疯草中毒是一种慢性病，家畜在采食含有疯草毒素苦马豆素的某些黄芪属和棘豆属植物数周后会发病。本综述的目的是介绍苦马豆素毒代动力学以及疯草引起的临床和组织学病变的最新研究。苦马豆素抑制细胞甘露糖苷酶，导致类似于遗传性甘露糖苷贮积症的溶酶体贮积病。临床中毒的诊断通常通过记录接触史、识别神经症状以及分析血清中的α-甘露糖苷酶活性和苦马豆素来进行。中毒动物的所有组织都含有苦马豆素，大多数组织的清除率约为20小时（半衰期）。肝脏和肾脏的清除率约为60小时（半衰期）。这表明应允许中毒动物有28天的休药期，以确保苦马豆素完全清除。中毒会导致大多数组织出现空泡化，在神经元和上皮细胞中最为明显。大多数这些组织学病变在停止中毒后不久就会消退；然而，一些神经变化是不可逆的且是永久性的。
