Estrogen-dependent DNA synthesis and parenchymal cell proliferation in the liver of adult male Xenopus frogs.
Estradiol-17 beta treatment of adult male Xenopus laevis induces liver parenchymal cells to synthesize DNA and proliferate. DNA synthesis begins 3 to 4 days after estrogen treatment and continues for approximately 10 days. Over this 2-week period, the total number of liver parenchymal cells increases fourfold, the wet weight of the liver remains constant, and there is a 50% reduction in cell volume. The elevated number of cells persists for several months and then returns to the control value. The extent of proliferation is hormone dose dependent. Pulse-chase experiments demonstrate that as a result of hormone treatment a minority of the parenchymal cells in the initial population enter the cell cycle, and via repeated divisions become the majority (79%) of the population by Day 14. The implications of this phenomenon for estrogen-induced liver cell differentiation and vitellogenin gene function are discussed.
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects*; D002645:Chickens; D004247:DNA / Q000096:biosynthesis*; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D008099:Liver / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D014819:Vitellogenins / Q000235:genetics; D014982:Xenopus laevis
D014819:Vitellogenins; D004958:Estradiol; D004247:DNA