Dose response of sheep poisoned with locoweed (Oxytropis sericea)
Dose response of sheep poisoned with locoweed (Oxytropis sericea)
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DOI：
10.1177/104063879901100510
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发表时间：
1999-09-01
影响因子：
1.5
通讯作者：
Molyneux, RJ
中科院分区：
文献类型：
--
作者：
Stegelmeier, BL;James, LF;Molyneux, RJ
疯草中毒发生在牲畜食用含有苦马豆素的黄芪和棘豆物种数周。虽然中毒的临床和组织学变化已被描述，但导致严重或不可逆损害的苦马豆素摄入剂量或持续时间尚不清楚。本研究的目的是记录产生临床中毒和组织学病变的苦马豆素剂量。21只混种的威瑟犬通过管饲法给予磨碎的丝光棘豆，以获得0.0、0.05、0.1、0.2、0.4、0.8和1.0 mg/kg/天的苦马豆素剂量，持续30天。接受大于或等于0.2 mg/kg剂量的绵羊增重低于对照组。16天后，接受大于或等于0.4 mg/kg剂量的动物出现抑郁，不愿移动，并且不吃饲料配给。所有给药组均出现血清生化变化，包括α-甘露糖苷酶降低、天冬氨酸转氨酶和碱性磷酸酶升高，以及乳酸脱氢酶、钠、氯、镁、白蛋白和渗透压的偶发变化。在以下组织和苦马豆素剂量下观察到典型的疯草诱导的细胞空泡化：胰腺外分泌大于或等于0.05 mg/kg;近曲肾和甲状腺滤泡上皮大于或等于0.1 mg/kg;大于或等于0.2 mg/kg时，浦肯野细胞、枯否细胞、脾和淋巴结巨噬细胞以及膀胱移行上皮;基底神经节、中脑的神经元。以及小脑神经元和神经胶质，大于或等于0.8 mg/kg。当组织苦马豆素浓度为150 ng/g时，通常发现组织学病变。临床和组织学病变，特别是小脑病变，提示神经功能障碍，即使在低剂量的每日苦马豆素0.2毫克/公斤，这表明，长期疯草暴露，即使在低剂量，导致显着的生产损失以及组织学和功能损伤。
Locoweed poisoning occurs when livestock consume swainsonine-containing Astragalus and Oxytropis species over several weeks. Although the clinical and histologic changes of poisoning have been described, the dose or duration of swainsonine ingestion that results in significant or irreversible damage is not known. The purpose of this research was to document the swainsonine doses that produce clinical intoxication and histologic lesions. Twenty-one mixed-breed wethers were dosed by gavage with ground Oxytropis sericea to obtain swainsonine doses of 0.0, 0.05, 0.1, 0.2, 0.4, 0.8, and 1.0 mg/kg/day for 30 days. Sheep receiving greater than or equal to 0.2 mg/kg gained less weight than controls. After 16 days, animals receiving greater than or equal to 0.4 mg/kg were depressed, reluctant to move, and did not eat their feed rations. All treatment groups had serum biochemical changes, including depressed alpha-mannosidase, increased aspartate aminotransferase and alkaline phosphatase, as well as sporadic changes in lactate dehydrogenase, sodium, chloride, magnesium, albumin, and osmolarity. Typical locoweed-induced cellular vacuolation was seen in the following tissues and swainsonine doses: exocrine pancreas at greater than or equal to 0.05 mg/kg; proximal convoluted renal and thyroid follicular epithelium at greater than or equal to 0.1 mg/kg; Purkinje's cells, Kupffer's cells, splenic and lymph node macrophages, and transitional epithelium of the urinary bladder at greater than or equal to 0.2 mg/kg; neurons of the basal ganglia, mesencephalon. and metencephalon at greater than or equal to 0.4 mg/kg; and cerebellar neurons and glia at greater than or equal to 0.8 mg/kg. Histologic lesions were generally found when tissue swainsonine concentrations were congruent to 150 ng/g. Both the clinical and histologic lesions, especially cerebellar lesions an suggestive of neurologic dysfunction even at low daily swainsonine doses of 0.2 mg/kg, suggesting that prolonged locoweed exposure, even at low doses, results in significant production losses as well as histologic and functional damage.