To gain insight into the role of epithelial ion channels, pumps, and cotransporters in regulating airway water and mucociliary transport, we administered inhibitors of the Na+ channel (amiloride), 3Na-2K-adenosinetriphosphatase (acetylstrophanthidin), and Na-K-2Cl cotransporter (furosemide) to anesthetized dogs and/or baboons. Tracheal ciliary beat frequency was measured by using heterodyne las...

Epithelial ion transport is essential to renal homeostatic function, and it is dysregulated in several diseases, such as hypertension. An understanding of the insect renal (Malpighian) tubule yields insights into conserved epithelial ion transport processes in higher organisms and also has implications for the control of insect infectious disease vectors. Here, we examine the role of the Na(+)-...

Aldosterone elevates Na /K /2Cl cotransporter activity in rabbit cardiomyocytes within 15 min, an effect blocked by K-canrenoate and thus putatively mineralocorticoid receptor mediated. Increased cotransporter activity raises intracellular [Na ] sufficient to produce a secondary increase in Na -K pump activity; when this increase in intracellular [Na ] is prevented, a rapid effect of aldosteron...

THE ROLE OF Na-K-ATPase in the regulation of epithelial cell polarity, adhesion, and migration has been demonstrated. Some of these processes, such as tight junction (TJ) formation, require ion transport function of Na-K-ATPase by its catalytic subunit Na-K. Other functions, such as motility suppression, cell adhesion, and contact inhibition, are mediated by the regulatory subunit Na-K, typical...