The efficacy of a modified aluminosilicate as a detoxifying agent in Fusarium toxin contaminated maize containing diets for piglets.

Two feeding experiments with female weaned piglets were carried out applying a complete two by two factorial design to investigate the effects of the dietary inclusion of 500 g/kg Fusarium toxin contaminated maize (8.6 mg/kg deoxynivalenol (DON); 1.2 mg/kg zearalenone (ZON)) and of 4 g/kg aluminosilicate (AS) as a detoxifying agent. The resulting four diets were fed ad libitum to a total of 80 piglets (20 piglets per group, allotted to a total of 20 pens) covering a live weight range of 10.5 +/- 1.3 to 27.5 +/- 4.4 kg in experiment 1, and to a total of 48 piglets (12 piglets per group, allotted to 12 pens) covering a live weight range of 9.7 +/- 1.8 to 21.4 +/- 4.8 kg in experiment 2. The animals of experiment 1 were slaughtered on days 34-36 of feeding the experimental diets. The mycotoxin analyses revealed that the control maize also contained considerable concentrations of Fusarium toxins, but the differences in DON and ZON concentrations between control and contaminated diets were sufficiently high to demonstrate both dose-related toxin effects. Voluntary feed intake and live weight gain of the animals were significantly reduced by the inclusion of Fusarium toxin contaminated maize into the diets in both experiments, while a significantly decreased feed to gain ratio was found in experiment 1. Furthermore, the relative weight of the uterus, stomach and heart of the animals fed the contaminated maize containing diets were significantly increased. Serum albumin concentrations and the activity of GLDH were significantly reduced by the inclusion of the contaminated maize. The addition of AS to the Fusarium toxin contaminated diets did not prevent or alleviate any of the mentioned effects. Moreover, the feed intake tended to be decreased by this supplementation in both experiments, while a significantly decreased feed to gain ratio was indicated for this factor in experiment one as well. The serum concentration of albumin and the activities of ASAT and gammaGT were significantly increased if AS was present in the diets while serum concentration of cholesterol and alpha-tocopherol were decreased significantly or in tendency, respectively. The concentrations of retinol and retinyl esters in liver and serum were not altered by the treatments. The analysed concentrations of zearalenone (ZON) and its metabolites in the bile fluid clearly indicated the differences in dietary ZON concentrations and showed that AS was ineffective in preventing the absorption of the toxin from the gastrointestinal tract. Also, serum concentrations of DON reflected the DON intake prior to sampling. However, there were no differences between groups fed diets with or without AS which also suggests the inefficacy of the tested AS in preventing the DON absorption. The present investigations failed to demonstrate a detoxifying capacity of the tested additive and emphasize the general necessity for a critical verification of detoxifying agents in vivo.

[Results of the toxicokinetics of bromoxynil in rats]. / Ergebnisse zur Toxikokinetik von Bromoxynil an Ratten.

The present paper reports on toxicokinetics of bromoxynil after oral administration of two different dosages in male and female rats. The concentrations measured in serum proceed with a terminal half life of 20 h. Differences in sex are expressed in MRT- and AUC-values. The simulated concentration course after multiple dosing corresponds essentially to experimental course (male rats). Toxicokinetics studies of liver and kidney show a saturation kinetics in kidney after oral administration of a high dose (100 mg/kg KM) in case female rats.

Diurnal variation of cytochrome P-450 dependent parameters after administration of the phenoxyacid herbicide dichlorprop to rats.

The circadian rhythm of ethylmorphine N-demethylase (ND) and hexobarbital sleeping time (HBS) was studied in noninduced and dichlorophenoxy propionic acid (DP) induced adult male rats. DP was gavaged (40 mg/kg bw) at 1.00, 7.00, 13.00 or 19.00 hr. After 21 days the above mentioned parameters were determined corresponding to the time point of DP administration. ND showed a biphasic oscillation (peak activities at 1.00 and 13.00 hr), whereas HBS was significantly shortened only at 1.00 hr. The effects of DP--ND-induction and HBS-shortening--were significant only, when the circadian phase of these parameters was low (i.e. at 7.00 and 19.00 hr for ND and at 7.00 hr for HBS). Consequently, attention should be paid not only to circadian rhythms of the cytochrome P-450 system per se but also to circadian alterations of the inducibility of this system.

Toxicokinetics of the herbicide dichlorprop and its leucinate and their action on liver mixed function oxidase in rats.

The concentrations of dichlorprop and its leucine conjugate in serum and bile of rats have been determined at different periods after a single oral dosage of these compounds (30 or 300 mg/kg body weight). From the results it can be concluded that dichlorprop is excreted by active renal mechanisms resembling that described for 2,4,5-T. It is suggested that the leucinate is excreted more by the biliary route. Investigations of the liver demonstrate that both compounds are able to induce mixed function oxidases.

Differences in the distribution of methyl mercury in erythrocytes, plasma, and brain of Japanese quails and rats after a single oral dose.

Distribution of a single oral dose of methyl mercury (10 mg Hg/kg body weight) was followed from 90 min up to 120 h in plasma, erythrocytes, and brain of Japanese quails and rats. Significantly higher Hg concentrations were observed in plasma and brain of quails and red blood cells of rats. Blood/brain ratio decreased in quails from 6 to 2 at 24 h and 120 h respectively, whereas it increased in rats. Erythrocyte/plasma ratio in quails was about three times lower and averaged 54. The differences in Hg distribution were accompanied by a more than 3-fold higher acute toxicity in quails under adequate experimental conditions.