Effect of light deprivation on the ERG responses of taurine-deficient rats

The decrease of taurine levels in the retina of taurine-depleted rats treated with guanidinoethane sulfonate (GES) reduced the amplitude of the a- and b-waves of the electroretinogram, registered as a function of the log relative intensity stimulus. The effect was observed either in rats exposed to a light-darkness cycle or to continuous darkness; this effect was somewhat more pronounced in retinas of rats exposed to light. Values obtained from the Naka-Rushton equation for the V-log I curve for the a-wave showed that the half-saturating intensity was unchanged but Vmax was decreased by GES treatment. Implicit times for the b-wave delayed whereas those for the a-wave were unaffected by the treatment.