Amiloride-Sensitive Sodium Channels: Physiology and Functional Diversity

Book excerpt: Sodium reabsorbing epithelia play a major role in whole-body sodium homeostasis. Some examples of sodium regulating tissues include kidney, colon, lung, and sweat ducts. Sodium transport across these membranes is a two-step process: entry through an amiloride-sensitive sodium channel and exit via the ouabain-sensitive sodium/potassium ATPase. The sodium entry channels are the rate-limiting determinant for transport and are regulated by several different hormones. The sodium channels also play a significant role in a number of disease states, like hypertension, edema, drug-induced hyperkalemia, and cystic fibrosis. Amiloride-Sensitive Sodium Channels: Physiology and Functional Diversity provides the first in-depth exchange of ideas concerning these sodium channels, their regulation and involvement in normal and pathophysiological situations. Summarizes current state of amiloride-sensitive sodium channel field Analyzes structure-function of epithelial sodium channels Discusses immunolocalization of epithelial sodium channels Examines hormonal regulation of sodium channels Discusses sodium channels in lymphocytes, kidney, and lung Considers mechanosensitivity of sodium channels Provides ideas on sodium channels and disease