Chronic taurine treatment ameliorates reduction in saline-induced diuresis and natriuresis

Background. Taurine is an osmolyte found in high concentration in the kidney. Both the modulation of tissue taurine stores and the exogenous administration of taurine are known to affect renal function. Therefore, it is likely that taurine therapy could benefit the dysfunctional kidney. Methods. To test this idea, the present study examined the effect of chronic taurine administration on the excretory responses to acute saline volume loading by the unilaterally nephrectomized (UNX) control and the UNX glucose-intolerant rat (ages 3 to 9 months). Results. Sham-operated animals excreted similar amounts of the administered fluid and sodium loads with age. However, unilateral nephrectomy was associated with a significant reduction in the response to saline volume loading. This defect was prominent at a younger age (that is, 3 months) in the UNX glucose intolerant than the UNX control (6 months old) rat. Chronic taurine treatment ameliorated the reduction in saline-induced diuresis and natriuresis by both the UNX control and the UNX glucose intolerant rat. Both an increase in glomerular filtration and a reduction in tubular reabsorption of fluid and sodium caused this taurine-mediated improvement in renal excretory function. Conclusion. Taurine treatment protects the kidney of the UNX rat against an age-dependent decline in excretory efficiency.