Intrahepatic biliary tract--oral contraceptives. Electron microscopic examinations of 27 surgical liver biopsies.

An electron microscopic study of 27 liver biopsies of patients on oral contraceptives is reported with special attention to the alterations of intrahepatic biliary tract. Bile ductules were normal. Bile canaliculi were damaged in each case with severe alterations of the canalicular membranes. An accumulation of granular, filamentous, lipoid material or collagen fibres could be observed in the lumina of canaliculi. Wide layer of dense actin-like filaments was present in the pericanalicular area and along the lateral cell membrane of liver cells. It is presumed that the ultrastructural alterations of canalicular cell membranes and of pericanalicular cytoplasm are connected with an impaired bile secretion in patients on oral contraceptives.