Uptake of taurine by platelets in retinitis pigmentosa

Uptake of 3H-taurine by platelets from twelve patients with retinitis pigmentosa (R.P.) and from healthy controls was measured. Platelets were incubated in autologous plasma with 3H-taurine for different times and at different substrate concentrations. The uptake of taurine by R.P. platelets at each incubation time was about two-thirds of the control value, the difference being statistically significant. Km was about the same, but Vmax was lower in R.P. platelets. The results suggest that R.P. is a disease affecting not only the eye but also taurine transport and/or storage in general.