Actions of guanidinoethane sulfonate on taurine concentration, retinal morphology and seizure threshold in the neonatal rat.

Administration of the taurine transport inhibitor, guanidinoethane sulfonate (GES) to pregnant rats depleted taurine concentrations to approximately one-half of normal values in the newborn progeny. By 5 days of age taurine concentrations had returned to normal in all organs tested with the exception of the lungs. Longer postnatal exposure to GES significantly depressed tissue taurine levels. Prenatal exposure to GES had no effect on fetal development or the capability of the newborn rat to biosynthesize or transport taurine. Pre- and postnatal exposure to GES produced a degeneration of the photoreceptor layer of the retina similar to that observed in cats fed a taurine deficient diet. The pentylene tetrazole chemoshock threshold in GES-treated pups was greater than that in control pups. These results indicate that prenatal exposure to GES deplete taurine concentrations in the newborn rat. Morphological changes are thereby produced in the retina of rat that are similar to those observed in animals having limited ability to synthesize taurine which are maintained on a taurine-free diet.