**4.2.5 Other hormones**

Dopamine mediates renal phosphate excretion, which is affected by the function of renalase (Weinman et al. 2011). Chronic infusion of angiotensin II into rats was demonstrated to increase the expression of NaPi-IIa in PTC brush border membranes by posttranscriptional mechanisms (Xu et al. 2004). This increase of NaPi-IIa may be associated with an angiotensin II-mediated decrease in the expression of megalin that plays a role in endocytosis and the degradation of NaPi-IIa (Bachmann et al. 2004). Insulin may also be involved in regulating sodium-dependent phosphate transporters (Kunkler et al. 1991; Li et al. 1996). Glucocorticoids inhibit phosphate uptake in primary cultured rabbit PTCs via both nongenomic and genomic mechanisms (Park, Taub, and Han 2001). In addition, estrogen causes the PTH-independent downregulation of NaPi-IIa in PTCs (Faroqui et al. 2008).
