Loop diuretics tend to be bound to plasma protein and therefore are not filtered. They enter the tubule via secretion by the [[Reabsorption and Secretion Along the Proximal Tubule - Anatomy & Physiology#Primary Active Secretion - Organic Acids and Bases|organic acid transport mechanisms]]. | Loop diuretics tend to be bound to plasma protein and therefore are not filtered. They enter the tubule via secretion by the [[Reabsorption and Secretion Along the Proximal Tubule - Anatomy & Physiology#Primary Active Secretion - Organic Acids and Bases|organic acid transport mechanisms]]. |