Seizure-susceptibility and decreased taurine transport in the genetically epileptic rat.

P(2) fractions from brains of genetically seizure-susceptible (SS) rats as compared to seizure-resistant (SR) rats show decreased high affinity uptake of taurine. Uptakes of GABA and glutamate into P(2) fractions did not differ between the substrains. In neonatal SS rats that had never had a seizure, the uptake of taurine is decreased both into the whole brain in vivo and into P(2) fraction in vitro, as compared to age-matched SR rats. This indicates that decreased uptake is not a consequence of seizure activity per se. In non-seizure susceptible progeny of SS rats, the uptake of taurine into P(2) fraction did not differ significantly from that of SR rats. In kidney cortex slices from SS rats, taurine uptake is slightly greater than in slices from SR rats. We propose that the decreased taurine transport in the P(2) fraction of the brains of SS rats may reflect a defect in transport in vivo that contributes to seizure-susceptibility.