In the rat, estrone sulphate is the main serum metabolite of oral oleoyl-estrone.
Two different oral doses of oleoyl-estrone: 1 and 10 nmol/g a day were given once to male Wistar rats. The serum levels of free estrone, estrone sulphate, estradiol, and acyl-estrone were measured at intervals up to 72 h after the gavage. Oleoyl-estrone was rapidly absorbed; with the 1 nmol/g dose no changes were observed in plasma acyl-estrone but levels increased dramatically with 10 nmol/g, peaking at 6 h; high acyl-estrone levels were maintained up to 24 h, returning to normalcy at 48 h. With the 10 nmol/g dose, free estrone at most doubled its levels but estrone sulphate concentrations rose by one order of magnitude; in both cases, the increases soon (2 h) reached a plateau that was maintained for almost two days. Estradiol levels remained unchanged except for a transient peak at 2 h at the 10 nmol/g dose. The relationship between free estrone and its sulphate was linear, and those of estrone and estrone sulphate versus acyl-estrone showed the existence of an upper serum concentration limit for both molecules. The results hint at estrone sulphate being an important metabolite of oleoyl-estrone disposal, confirm the limited estrogenic response to oleoyl-estrone administration and agree with a rapid absorption and disposal of oleoyl-estrone, nevertheless maintaining high circulating levels of the ester for a time after its oral administration.
Cabot
C
C
Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona, 08028 Barcelona, Spain.
González-Martínez
D
D
Fernández-López
J-A
JA
Alemany
M
M
D000284:Administration, Oral; D000818:Animals; D019440:Anti-Obesity Agents / Q000097:blood / Q000493:pharmacokinetics*; D004958:Estradiol / Q000097:blood; D004970:Estrone / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics; D008297:Male; D009829:Oleic Acids / Q000097:blood / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar
D019440:Anti-Obesity Agents; D009829:Oleic Acids; D004970:Estrone; D004958:Estradiol; C108709:oleoyl-estrone; C017296:estrone sulfate