Electron Microscopic Study on Uptake and Excretion of Biligrafin by the Hepatic Parenchymal Cells in Rats

After intravenous injection of Biligrafin, the changes of the cytoplasmic organellae in the liver cells of the rats were examined electron microscopically and the following results were obtained. Discussion on uptake and active transport of substance from plasma to bile is also made. 1) At five minutes following injection of Biligrafin, the smooth-surfaced endoplasmic reticulum showed marked development and distension of the lumen which contained some dense granules with an approximate diameter of 40 to 80 mμ. Proliferation of the endoplasmic reticulum was more prominent at the sinusoidal area in the liver cell. 2) At 60 minutes the Golgi complex showed a prominent appearance, and the vesicles and vacuoles contained many dense granules. Near the bile canaliculi, similar granules were recognized mainly within the smooth-surfaced endoplasmic reticulum. Though there was no increse of the lysosomes, they occasionally contained the same granules especially in the vicinity of the bile capillary. 3) The mitochondria and the nucleus revealed no remarkable changes. 4) From these findings, the following conclusion has been obtained as to the mechanism whereby the hepatic parenchymal cells move Biligrafin particles across the cytoplasm from plasma to bile. Biligrah particles taken up by pinocytosis and / or phagocytosis at the sinusoidal surface are enveloped by the smooth- surfaced endoplasmic reticulum, transported to the Golgi complexes where the materials may be concentrated, transferred chiefly to the smooth-surfaced endoplasmic reticulum and finally discharged into the bile capillaries.