Impairment of vitamin A uptake by rat hepatocytes and fat storing cells determined by Monensin--morphological observations.

The action of the Na+/H+ antiport monensin on vitamin A uptake by rat liver has been studied in vivo. The quickfading autofluorescence of vitamin A has been used for the determination of vitamin A uptake by the liver. Pretreatment of rats intraperitoneally with monensin decreases the uptake of vitamin A by hepatocytes and its transfer for storage to fat storing cells. Pretreatment of rats intraperitoneally with vitamin A for a short time, then with monensin, shows that the hepatocytes no longer transfer vitamin A to fat storing cells for storage. These results might indicate that monensin impairs the uptake of vitamin A by the hepatocytes and might also impair the transport of vitamin A from parenchymal to perisinusoidal cells.