Differential responsiveness of avian vitellogenin I and vitellogenin II during primary and secondary stimulation with estrogen.
Avian vitellogenin consists of two major species, VTG I and VTG II, which show major differences in structure and immunological properties suggesting that VTG I and VTG II are distinct gene products. During primary stimulation with estrogen, VTG I was found to accumulate in plasma much more slowly than VTG II. At 1 day after hormone treatment VTG I was only 1-3% of VTG II, but by day 5 VTG I increased to approximately 25% of VTG II. Measurements of hepatic vitellogenin synthesis confirmed the slower induction and reduced expression of VTG I. A further difference was noted in the amnestic or memory response to secondary estrogen treatment. Measurements of VTG I and VTG II accumulation and synthesis after primary and secondary estrogen treatment showed that the memory response occurs to a much greater extent for VTG I than VTG II. These differences indicate that the inductions of VTG I and VTG II are not tightly coupled.
D000818:Animals; D002645:Chickens; D004054:Diethylstilbestrol / Q000494:pharmacology; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D004967:Estrogens / Q000494:pharmacology*; D007700:Kinetics; D008074:Lipoproteins / Q000097:blood*; D008099:Liver / Q000378:metabolism; D008297:Male; D014819:Vitellogenins / Q000096:biosynthesis / Q000097:blood*
D004967:Estrogens; D008074:Lipoproteins; D014819:Vitellogenins; D004054:Diethylstilbestrol