Liver function and histology in various species of animal treated with non-lethal doses of aflatoxin B1

Induced aflatoxicosis in rabbits: blood coagulation defects

The effect of acute and subchronic experimental aflatoxicosis on blood clotting activity and platelets was evaluated. Male New Zealand White rabbits (weighing 2.4-3.2 kg each) were used. In Experiment 1, 19 rabbits were given orally 0.05 mg of aflatoxin B1 (AFB1)/kg of body weight daily from Day 0 through Day 23. Blood samples were collected before dosing and on Days 2, 5, 9, 12, 16, 19, and 23 of the experimental period. In Experiment 2, 40 rabbits were given a single dose of 0.4 mg of AFB1/kg of body weight. Blood samples were collected before dosing and at 12, 24, 36, and 48 hr after dosing. When compared to baseline and control animal values, one-stage prothrombin times and activated partial thromboplastin times of aflatoxin-dosed rabbits were lengthened, and there was a statistically significant decrease in fibrinogen, Factor IX, VIII, and V activities. Platelet counts were significantly increased in subacutely exposed rabbits, and platelet size was decreased in single high-dose treated groups. Factor deficiencies were attributed to a combination of decreased factor synthesis from hepatic insufficiency and consumptive coagulopathy or primary fibrinolysis.

A delay in blood clotting of chickens and ducks induced by aflatoxin treatment

Using the thrombotest technique blood clotting times were measured in the duck and the chicken after an intraperitoneal (I.P.) administration of aflatoxin B1 (58 microgram/kg body weight). Six hours after injection, the average thrombotest (blood clotting) time of the blood of the young duck was 194.5 +/- 1.3 sec (control time was 101.5 +/- 1.4, P less than .0001) and that of the young chicken averaged 70.2 +/- sec (control time was 51.7 +/- 2 sec, P less than .001). Corresponding times for the aflatoxin-treated adult birds were 249.5 +/- 1.4 sec (control, 118.5 +/- 1.1 sec; P less than .001) and 82.9 +/- .2 sec (control, 66.8 +/- .1 sec; P less than .001) for the duck and chicken respectively. In addition to the relatively low concentration of blood clotting factors in the plasma of the bird the present results suggest that there is a weak interaction of blood clotting factors II, VII, IX, and X in the avian species during aflatoxin poisoning. There is an inter-species difference in the anticoagulant effects of aflatoxin in the avian class.

In vitro effects of aflatoxin B1 on the activities of three hydrolases

The in vitro effects of aflatoxin B1 on the activities of trypsin, amylase and lipase in the pancreatic extract of male albino Wistar rats have been studied. Activities of the 3 hydrolases were inhibited at 1 microgram/ml, 200 microgram/ml and 400 microgram/ml concentrations of aflatoxin B1, with the exception that at the 1 microgram/ml concentration the activity of lipase was stimulated. Lineweaver-Burk reciprocal plots indicate non-competitive inhibition of the 3 hydrolases.