Distribution of Filipin-sterol Complexes in Rat Hepatocytes

: Distribution of cholesterol in rat hepatocytes under normal untreated and phenobarbital-treated conditions was studied by freeze-fracturing using filipin. In untreated rat hepatocytes, filipin-sterol complexes were observed on intercellular plasma membranes as well as on lysosomes and microbodies. These complexes were evenly distributed. In phenobarbital-treated rat hepatocytes, filipin-sterol complexes in the lysosomes or microbodies were distributed unevenly. In the bile canaliculi, no filipin-sterol complexes were noted. Based on these findings, the functional state of the organellae concerned was discussed.