Protective effect of taurine against acute paraquat intoxication in rats.

The effect of taurine (TA) on acute paraquat (PQ) intoxication was investigated in rats. Treatment with TA was begun 10 min after rats received a s. c. injection of PQ 40 mg/kg. Saline (0.9%) or 5% TA solution were infused i.v. for 5-6 min (short-interval infusion study). One hour after TA infusion, PQ concentration in the blood was increased and that in the urine was lowered, as compared with those in the saline-infused group. Significant increases of the PQ concentration was observed in kidney at 3 hours after TA administration. Excreted urine volume was significantly higher in the TA group during the time-period of 0-1 and 0-5 hours after the 5% TA administration compared with that of the saline group. However, there were no significant differences in total urinary PQ excretion between the two groups. Saline or 2.5% and 5% TA was infused continuously during the time-period of 0-1, 0-3 or 0-5 hours (long-interval infusion study). A marked increase in PQ concentration in blood and a reduction of PQ concentration in kidney were noticed during the time-period of 1-5 hours after the 5%TA infusion. Urinary excretion was remarkably accelerated by 5% TA infusion and the total urine volume increased to 20 times during the time-period 0-1 hour and 1.7 times during the time-period of 3-5 hours as compared with the saline control. In addition, urinary volume during the time-period of 0-5 hours almost reached that of 5% TA volume which infused to animals. The mortality rate of the groups that received either single or double short-time infusion of 5% TA was 100%. Thus, these results suggest that a long continuous infusion of 5% TA increased urine output and inhibits of PQ accumulation in renal tissue despite a rise in blood PQ concentration.