In this study, plasma and platelet taurine content and fluxes were determined in 38 type 2 diabetic patients and in 26 healthy control subjects. Taurine levels in diabetic patients were significantly lower than in control subjects both in plasma (32.1 v 48.6 micromol/L, P = .000) and platelets (148 v 183 nmol/mg protein, P = .043). Platelet taurine uptake in diabetic patients was significantly reduced (321.2 v 524.9 pmol total taurine 10(8) platelet(-1) min(-20), P = .000), whereas taurine release increased in comparison to healthy controls (38.7 v 29.5% of platelet 3H taurine at the start of incubation, P = .000). These results may reflect modified systems of taurine carriers or a compensatory mechanism in response to an increase of other organic osmolytes.