Taurine and the renal system

Abstract

Taurine participates in a number of different physiologic and biologic processes in the kidney, often reflected by urinary excretion patterns. The kidney is key to aspects of taurine body pool size and homeostasis. This review will examine the renal-taurine interactions relative to ion reabsorption; renal blood flow and renal vascular endothelial function; antioxidant properties, especially in the glomerulus; and the role of taurine in ischemia and reperfusion injury. In addition, taurine plays a role in the renal cell cycle and apoptosis, and functions as an osmolyte during the stress response. The role of the kidney in adaptation to variations in dietary taurine intake and the regulation of taurine body pool size are described. Finally, the protective function of taurine against several kidney diseases is reviewed.

Figure 1

A model illustrates the 2 Na⁺:1 taurine:1 Cl^- stoichiometry of taurine transport.

Figure 2

Taurine transport is membrane surface-specific.

Figure 3

(a) The promoter region of TauT contains important binding sites. (b) Details of the intracellular signaling that regulate the gene.

Figure 4

Taurine’s role as an osmolyte is shown by its net movement under different conditions of tonicity.

Figure 5

(a) Location of the TonE site on the TauT gene promoter region; (b) Model of TonE and TauT gene activity following exposure to hypertonic conditions.

Figure 6

The renal adaptive response to dietary taurine intake conserves the total taurine body pool by reabsorbing or excreting taurine depending on its availability.