Role of Novel Biomarkers in Chronic Kidney Disease: Urotensin II

Urotensin II (UT) is an 11-amino-acid peptide widely expressed in the nervous system, heart, and kidneys. High UT levels are implicated in myocardial and renal dysfunction, and UT antagonists are considered as a possible treatment for these conditions. However, some studies involving patients with coronary heart disease, chronic kidney disease (CKD) and end-stage renal disease (ESRD) suggest that UT could have a dual role for the cardiovascular and renal systems in these diseases. In the cardiovascular system, UT acts as a vasoactive and inotropic substance. The kidney actively synthesizes UT, and urinary UT concentration far exceeds plasma UT concentra- tion. Clinical outcomes are inversely related to UT levels, and this association was reported for the first time in a cohort of patients with ESRD. In uremic people, high UT may underlie a cardioprotective situation. In agreement with this hypothesis, relatively higher UT levels were associated with a better left ventricular (LV) systolic function and relatively low LV posterior wall thickness in ESRD. These findings could be explained by the interference of UT with sympathetic activity and nitric oxide (NO) synthesis.