The fine structure of the liver cells in the bat (Myotis myotis) during hibernation,arousal and forced feeding

Summary The ultrastructure of liver cells was studied in three groups of bats (Myotis myotis) captured in March. 1. Hibernating animals: The liver cells contain much glycogen and large mitochondria, poorly developed ER, relatively well developed Golgi apparatus, various amounts of lysosomes. Most of the bile canaliculi are closed. 2. Non-hibernating, starving animals: 24 hours after arousal the glycogen and lipid droplets disappear from the liver cells, the mitochondria swell slightly. There is no essential alteration in the ER. In the liver cells of the starving animals numerous autophagic vacuoles appear including disintegrated cytoplasmic components. 3. Non-hibernating force-fed animals: They were given food rich in fat and protein, containing sugar and a drug increasing bile secretion. Within an hour, glycogen and lipid reappears in the liver cells, autophagic vacuoles disappear, mitochondria become larger. After feeding, the Golgi apparatus hypertrophies considerably, many bile canaliculi open, the number of the peribiliary lysosomes decreases.This paper is dedicated to Professor W. Bargmann on the occassion of his 60th birthday.