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.

Comparative in vitro metabolisms of dimethylnitrosamine in animals of six different species.

The in vitro metabolisms of dimethylnitrosamine (DMN) by liver slices and microsomal + soluble fractions, respectively, were studied in the rat, guinea pig, cat, duck, lizard and monkey using disappearance of DMN and the formation of formaldehyde, in situ, as indices of the decomposition of the compound. All the animal species investigated metabolised DMN, and the rate of metabolism of the compound was highest in media containing cat tissue and lowest in that containing duck tissue. The rat and guinea pig however appeared to metabolise DMN at comparable rates. Our results would suggest that DMN demethylase activity in the liver is a linear function of time. These results are discussed in relation to the toxicity of possible DMN metabolites.

Interaction of N-(phosphonomethyl)glycine with some respiratory chain enzymes of isolated corn-shoot mitochondria.

Spectrophotometric measurements of the activities of some dehydrogenases and electron transfer complexes of isolated corn-shoot mitochondria revealed that N-(phosphonomethyl)glycine (PMG), a broad-spectrum, non-selective, and post-emergence herbicide, at a concentration of 6.25 x 10(-4)M enhanced by about 10% the activities of NAD+-linked malate and NAD+-linked isocitrate dehydrogenases. At concentrations of 5 x 10(-3)M and 10 x 10(-3)M PMG, the activities of succinate and the NAD+-linked dehydrogenases were reduced by at least 10% and 25%, respectively. Although no effect was observed on the activities of the electron transfer complexes at lower concentrations of PMG, these enzymes were inhibited by at least 10% and 20%, respectively, at 5.0 x 10(-3)M and 10 x 10(-3)M PMG.

The effect of dietary fat on the anticoagulant activity of aflatoxin B.

A single i.p. dose of aflatoxin B1 had no significant effect on the thrombotest clotting times of monkeys subsisting on low-fat and high-fat dietary regimens, respectively. There was a significant interaction between aflatoxin and dietary fat level.

Contamination of some fermented Nigerian beverages by carcinogenic nitrosamines.

A survey to determine the extent of the nitrosamine contamination of some popular fermented Nigerian beverages by dimethyl- and diethylnitrosamine has been carried out in the Lagos, Ogun, Oyo, Ondo, Kwara and Benue States of Nigeria, following the mass spectrometric detection of these carcinogens in palm wine and nono (sour milk). The indication is that the contamination of the drinks, namely, palm-wine, nono, pito, burukutu, and ogogoro, by both nitrosamines is widespread and occurs at the part per billion level. 0.6 - 22 mu g nitrosamine/l was found by routine thin layer and gas liquid chromatographic methods using authentic nitrosamines as reference standards. Because of the widespread contamination of the test beverages by dimethyl- and diethylnitrosamine, and the usually frequent occurrence of nitrosamine precursors in nature, it is presumed that these potent and versatile carcinogens could play a significant role in the formation of human cancers in the Nigerian population.

Short-term effects of aflatoxin B1 on serum lipids in subhuman primates.

Aflatoxin B1 significantly depressed serum lipid levels in specimens of Cercopithecus aethiops, Cercopithecus mona, Erythrocebus patas and Papio anubis. Serum cholesterol, total phospholipids and total lipids were not affected to the same extent.

Microbial nitrosamine formation in palm wine: in vitro N-nitrosation by cell suspensions.

The ability of certain species of bacteria and yeasts that usually contaminate fresh palm sap to induce the formation of the carcinogen dimethylnitrosamine from suitable precursors (trimethylamine, dimethylamine, nitrate, and nitrite) was investigated in vitro under neutral and acid pH conditions. In the incubation media containing cell suspensions of each species of test organism, namely, Aerobacter, Micrococcus, Serratia, Saccharomyces, and two unidentified yeasts and the precursors, added in varying concentrations, the presence of dimethylnitrosamine was indicated. The possible role of indwelling microorganisms in the elaboration of the hazardous compound in fermenting palm wine is discussed.

Comparative mutagenicity of palmotoxin Bo and aflatoxins B1 and M1.

The mutagenicity of palmotoxin Bo and of aflatoxin M1 relative to that of aflatoxin B1, the potent mutagen, was studied in five Ames' Tester Strains of Salmonella typhimurium (TA-98, TA-100, TA-1535, TA-1537, TA-1538). Aflatoxins B1 and M1 are both highly mutagenic in a microsome-mediated system in TA-100. The prediction of the relative carcinogenicity of aflatoxin M1 to aflatoxin B1 posed by the mutation of TA-100 is probably more authentic than TA-87. The mutagenic potency of palmotoxin Bo is less than that of either aflatoxin B1 or M1.