Osuna O, Edds G T, Blankespoor H D
Am J Vet Res. 1977 Mar;38(3):341-9.
This experiment was designed to compare 3 dose levels of aflatoxin B1 (0.0, 0.5, and 1.0 mg/kg of body weight) and 2 infection levels of Fasciola hepatica metacercariae (0 and 220) to determine whether an additive effect from aflatoxin B1 occurs when fascioliasis is present in dairy calves. Twenty-four male, Holstein calves, 4 weeks old, and averaging 45.8 kg each, were assigned at random to 6 treatment groups, 4 calves per group: group 1--negative control; group 2--0.5 mg of aflatoxin B1/kg; group 3--1.0 mg of aflatoxin B1/kg group 4--220 metacercariae; group 5--220 metacercariae plus 0.5 mg of aflatoxin B1/kg; and group 6-220 metacercariae plus 1.0 mg of aflatoxin B1/kg. The single oral dose of 220 metacercariae was given (groups 4, 5, and 6) at the start of the 10-week experiment, and 5 weeks later, the single oral dose of aflatoxin B1 was given (groups 2, 3, 5, 6). Results from the principals, as compared with that from the controls (group 1), included significant decreases of dry matter intake (P less than 0.006), body weight (P less than 0.024), and serum albumin (P less than 0.04), and in groups 4, 5, and 6 infected with 220 flukes, there were significantly increased values of prothrombin time (P less than 0.014), serum alkaline phosphatase (P less than 0.04), and serum sorbitol dehydrogenase (P less than 0.007). Significant differences in number of flukes recovered from liver were seen in groups 4 to 6 given 0, 0.5, and 1.0 mg of aflatoxin B1/kg (P less than 0.046). The single oral dose of 22* fluke metacercariae in groups 4, 5, and 6 resulted in significantly increased concentrations of serum total protein (P less than 0.003) and globulins (P less than 0.01). Results from the development of the flukes from metacercariae to the mature state with sizes, numbers, feeding habits, and pathologic lesions were described. Differences in numbers of flukes recovered from liver of groups 4 to 6 and the presence of pneumonia in calves of group 6 indicated aflatoxin B1 produced persisting, lowered resistance. In all animals necropsied, the liver was the organ most affected by aflatoxin B1 as well as with flukes. Periportal fibrosis, monocytic infiltration, fatty infiltration, and bile duct proliferation were the usual lesions induced by aflatoxin B1. Additive toxic effects were observed in the groups 5 and 6 dosed with flukes and aflatoxin B1, with significant variations of serum and plasma values, as well as increased severity of histopathologic changes.
本实验旨在比较黄曲霉毒素B1的3个剂量水平（0.0、0.5和1.0毫克/千克体重）以及肝片吸虫囊蚴的2个感染水平（0和220），以确定当奶牛犊存在片形吸虫病时，黄曲霉毒素B1是否会产生相加效应。24头4周龄、平均体重45.8千克的雄性荷斯坦犊牛被随机分配到6个处理组，每组4头：第1组为阴性对照；第2组为0.5毫克黄曲霉毒素B1/千克；第3组为1.0毫克黄曲霉毒素B1/千克；第4组为220个囊蚴；第5组为220个囊蚴加0.5毫克黄曲霉毒素B1/千克；第6组为220个囊蚴加1.0毫克黄曲霉毒素B1/千克。在为期10周的实验开始时，给第4、5和6组单次口服220个囊蚴，5周后，给第2、3、5和6组单次口服黄曲霉毒素B1。与对照组（第1组）相比，主要结果包括干物质摄入量显著降低（P＜0.006）、体重（P＜0.024）和血清白蛋白（P＜0.04），在感染220条吸虫的第4、5和6组中，凝血酶原时间（P＜0.014）、血清碱性磷酸酶（P＜0.04）和血清山梨醇脱氢酶（P＜0.007）的值显著升高。在给予0、0.5和1.0毫克黄曲霉毒素B1/千克的第4至6组中，从肝脏回收的吸虫数量存在显著差异（P＜0.046）。第4、5和6组单次口服22个吸虫囊蚴导致血清总蛋白（P＜0.003）和球蛋白（P＜0.01）浓度显著升高。描述了吸虫从囊蚴发育到成熟状态的大小、数量、摄食习性和病理病变。第4至6组从肝脏回收的吸虫数量差异以及第6组犊牛出现的肺炎表明，黄曲霉毒素B1产生了持续的、降低的抵抗力。在所有解剖的动物中，肝脏是受黄曲霉毒素B1以及吸虫影响最严重的器官。门静脉周围纤维化、单核细胞浸润、脂肪浸润和胆管增生是黄曲霉毒素B1引起的常见病变。在同时感染吸虫和黄曲霉毒素B1的第5和6组中观察到相加毒性作用，血清和血浆值有显著变化，组织病理学变化的严重程度也增加。
