Ultrastructural studies on the liver of rat treated with cyclosporin A; with the special reference to bile canaliculus

Cyclosporin A를 투여한 랫드 간장의 미세구조적 연구; 담세관을 중심으로

Cyclosporin A extracted from fungus Trichoderma polysporum Rifai and Cyclindrocarpon lucidum Booth serves as an important immunosuppressive drug in transplantation surgery. Systemic treatment with cyclosporin A induces an impairment of the biliary excretion of the bile salts and cholestasis. This study was designed to observe the Ultrastural changes of the hepatocytes and the bile canaliculi in cyclosporin A-induced intrahepatic cholestasis in rats. Cyclosporin A was injected into male Wistar rats intraperitoneally 50mg per kg body weight and rats were necropsied at 1, 3, 6, 9, 12, 24 hours. The liver tissues were observed with transmission and scanning electron microscopes and the results were as follows. Transmission electron microscopy: After cyclosporin A injection, SER and lysosomes were increased in the hepatocytes until 9 hours. At 12 hours after injection of cyclosporin A, RER with dilated cistern were increased, and SER, lysosomes in the cytoplasm were decreased. From 1 hour to 24 hours after injection of cyclosporin A, there were dilation of bile canalliculi and decreased or lost microvilli. At 24 hours the dilation of bile canaliculi were decreased. Scanning electron microsocopy: After cyclosporin A injection, the bile canaliculi were dilated and the microvilli were shortened, decreased or lost according to the sites. At 24 hours, the microvilli packing the bile canaliculi were observed. These observations suggest that cyclosporin A-induced cholestasis is associated with the dilation of bile canaliculi, increased microfilaments of the pericanalicular region and decreased or lost microvilli.