ENAC

ENAC may refer to:

Epithelial sodium channel

The epithelial sodium channel (short: ENaC, also: amiloride-sensitive sodium channel) is a membrane-bound ion-channel that is selectively permeable to Na⁺-ions and that is assembled as a heterotrimer composed of three homologous subunits α, β, and γ or δ, β, and γ. These subunits are encoded by four genes: SCNN1A, SCNN1B, SCNN1G, and SCNN1D.

The apical membranes of many tight epithelia contains sodium channels that are characterized primarily by their high affinity for the diuretic blocker amiloride. These channels mediate the first step of active sodium reabsorption essential for the maintenance of body salt and water homeostasis. In vertebrates, the channels control reabsorption of sodium in kidney, colon, lung and sweat glands; they also play a role in taste perception.

Location and function

ENaC is located in the apical membrane of polarized epithelial cells in particular in the kidney (primarily in the distal tubule), the lung, and the colon. It is involved in the transepithelial Na⁺-ion transport, which it accomplishes together with the Na⁺/K⁺-ATPase.