Then δ subunit of epithelial sodium channel in humans-a potential player in vascular physiology

Vascular epithelial sodium channels (ENaCs) made up of canonical alpha, beta, and gamma subunits have attracted more attention recently owing to their physiological role in vascular health and disease. A fourth subunit, delta-ENaC, is expressed in various mammalian species, except mice and rats, which are common animal models for cardiovascular research. Accordingly, delta-ENaC is the least understood subunit. However, the recent discovery of delta subunit in human vascular cells indicates that this subunit may play a significant role in normal/pathological vascular physiology in humans. Channels containing the delta subunit have different biophysical and pharmacological properties compared with channels containing the a subunit, with the potential to alter the vascular function of ENaC in health and disease. Hence, it is important to investigate the expression and function of delta-ENaC in the vasculature to identify whether delta-ENaC is a potential new drug target for the treatment of cardiovascular disease. In this review, we will focus on the existing knowledge of delta-ENaC and implications for vascular physiology and pathophysiology in humans.