Cholestasis: Pump failure, microvilli defect, or both?

Cholestasis may result either from a disturbance of the systems responsible for solute transport into the bile canaliculi (for example, the Na+ and K+-ATP-ase system) or from an alteration of canalicular microvilli (for example, that resulting from microfilament dysfunction). Evidence that both mechanisms operate is drawn from the analysis of experimental cholestasis induced by oestrogen, cytochalasin-B, and phalloidin.