Pannon White weaned rabbits were fed on diets artifi cially complemented with 2 mg/kg diet T-2 toxin, or
10 mg/kg diet fumonisin B1 (FB1), and both toxins in a combination (2+10 mg/kg, resp.). Th e control was
fed on a toxin free, fully identical diet. Blood was sampled aft er 2 and 4 weeks of administration. Body and
liver weight of the T-2 group was lower aft er 4 weeks. Aft er full red cell lysis in a hypotonic buff er cellular
membranes were isolated with centrifugation (30000 g/10 min) and the cation transport was implemented
as the breakdown of ATP in the absence and in the presence of a selective sodium pump inhibitor, ouabain.
Results were interpreted as the diff erence between the inhibited and non-inhibited treatments, and were
given as liberated inorganic phosphate (nmol Pi/mg protein/ h.) Th e red blood cell (RBC) total, ouabain
sensitive Na+/K+ ATPase activity decreased aft er 4 weeks in the T-2 group, increased in the FB1 group
and antagonistic eff ect was revealed by the T-2+FB1 group (enzyme activity identical with the control).
Th e RBC membrane fatty acid composition was altered by both mycotoxins similarly during the entire
feeding. Considering hematology, aft er 4 weeks T-2 alone and in combination with FB1 increased mean
cell volume (MCV). Time-dependent alterations in the T-2 group were signifi cant for MCV and the mean
cell hemoglobin, both parameters increasing. Th e active monovalent cation transport was signifi cantly
infl uenced by both T-2 and FB1 as well. Most probably FB1 exerts its sodium pump activity modifi cation
via an altered ceramide metabolism (behenic acid (C22:0) proportional decrease in the RBC membrane
composition), while for T-2 toxin a moderate membrane disruption and enzyme (protein) synthesis
inhibition was supposed (ca. 75% decrease of the ouabain sensitive sodium pump activity).
Th e research was supported by the Hungarian Academy of Sciences (MTA-KE “Mycotoxins in the food
chain” Research Group) and by the Bolyai János Research Grant (BO_499_13 to J. Sz-F.)
