Aim: The present study described hormonal and lipids concentrations
of follicles that develop under high progesterone
plasmatic levels, mimicking the second follicular wave.
Methods: All follicles were removed by aspiration in order to
generate a new follicular wave. Follicular fluid was then
obtained from either 3 day old follicles (F3) or 6 day old
follicles (F6). This experimental protocol was carried out at
20 days and 90 days post-partum on Frisian dairy cows that
had already returned to cyclicity.
Results: Estrogen active follicles (ratio of estrogen to progesterone
in follicular fluid higher than 1) have higher levels of
VEGF, IGF-I and linoleic acid, and have lower levels of NEFA,
oleic and arachidonic acid. Non-estrogen active follicular
fluid concentrations of IGF-I and NEFA were similar to
plasma concentrations. In contrast, estrogen active follicles
showed higher IGF-I and lower NEFA levels than plasmatic
ones that could be used to sustain follicular growth.
Conclusions: The results show that estrogen active follicles
might have their own metabolism. (Reprod Med Biol 2007; 6:
45–51)
