The absorption, distribution and elimination of fumonisin B(1) (and B(2)) after oral administration of Fusarium verticillioides (MRC 826) fungal culture, mixed into the experimental feed for 10 days, was studied in weaned barrows. In order to determine the absorption of FB(1) from the feed marked by chromium oxide, a special T-cannula was implanted into the distal part of pigs' ileum. During the feeding of toxin-containing diet (45 mg FB(1) kg(-1)) and until the tenth day after the end of treatment, the total quantity of urine and faeces was collected and their toxin content analysed. At the end of the trial, samples of lung, liver, kidney, brain, muscle, and fat were also collected and their fumonisin content analysed by LC-MS. The fumonisins appeared to decrease the reduced glutathione content in blood plasma and red blood cell haemolysate, possibly associated with in vivo lipid peroxidation. From a data set of 80 individual data and the concentration and rate of C(r) and fumonisins (FB(1), partially hydrolysed FB(1) and aminopentol) in the chymus, it could be established that the accumulative absorption of fumonisin B(1) was 3.9% +/- 0.7%. In the chymus, the FB(1) conversions into aminopentol and partially hydrolysed FB(1) were 1.0 and 3.9%, respectively. The degree of metabolism in faeces was variable, although the main product was the partially hydrolysed form, with very small amounts of the aminopentol moiety being recovered. In the investigated tissues the FB(1) conversion to aminopentol and partially hydrolysed FB(1) was 30 and 20%, respectively.